CFR NPRM

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[Federal Register: May 27, 1975 (Volume 40, Number 102)]
[Page 23048]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 23, 25, 27, and 29
Docket No. 14625; Notice No. 75-23
RIN
Airworthiness Review Program, Notice No. 5: Equipment and Systems Proposals

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AGENCY: Federal Aviation Administration, DOT
ACTION: Proposed Rules

SUMMARY:
14 CFR Parts 23, 25, 27, 29, 91, 121 and 127

The Federal Aviation Administration is considering amending Parts 23, 25, 27, 29, 91, 121 and 127 of the Federal Aviation Regulations to update and improve the airworthiness standards applicable to aircraft equipment and systems and to make related changes in the operating rules.

DATES: Comments on this notice must be received on or before August 25, 1975.
ADDRESSES:
FOR FURTHER INFORMATION CONTACT:

SUPPLEMENTARY INFORMATION:
This is one of a series of notices of proposed rule making issued, or to be issued, as a part of the First Biennial Airworthiness Review Program. Notice No. 74-33 (39 FR 36595; October 11, 1974) was the first. Amendments 21-43, 23-16, and 25-37, issued on December 31, 1974 (40 FR 2576; January 14, 1975) pursuant to that notice, incorporated certain form number and clarifying revisions into the Federal Aviation Regulations. In addition to Notice 74-33, the following Airworthiness Review notices of proposed rule making have been issued: Notice No. 75-10 (40 FR 10802, March 7, 1975); Notice No. 75-19 (40 FR 21866, May 19, 1975); and Notice 75-20 (40 FR 22110, May 20, 1975).
Interested persons, including the general public, manufacturers and users of aircraft and their components, both foreign and domestic, and foreign airworthiness authorities, are invited to participate in this proposed rulemaking by submitting such written data, views, or arguments as they may desire. Comments relating to any significant environmental or economic impact that might result because of the adoption of the proposals contained herein may also be submitted. Comments should identify this regulatory docket or notice number (Docket No. 14625; Notice No. 75-23) and be submitted in duplicate to: Federal Aviation Administration, Office of Chief Counsel, Attention: Rules Docket, AGC-24, 800 Independence Avenue, SW, Washington, D.C. 20591. All communications received on or before August 25, 1975, will be considered by the Administrator before taking action on the proposed rules. However, interested persons are urged to submit their comments as early as possible to facilitate rapid resolution of any issues raised. The proposals contained in this notice may be changed in the light of comments received. All comments submitted will be available in the Rules Docket for examination by interested persons.
On February 12, 1974, the FAA issued an invitation to all interested persons to submit proposals for consideration during the First Biennial Airworthiness Regulations Review (see Notice 74-5, 39 FR 5785, February 15, 1974). In that notice, the FAA announced that it would make available for comment by interested persons a compilation of proposals that were to be given further consideration as possible agenda items for the First Biennial Airworthiness Review Conference. On May 22, 1974, the FAA issued an announcement of the availability of the compilation of proposals containing over 1000 submissions by the FAA and interested persons, and invited all interested persons to submit comments on the proposals it contained (see Notice 74-5A, 39 FR 18662, May 29, 1974).
In response to that invitation for comments, the FAA received over 4900 individual comments contained in 74 submissions. Based on those comments and on the compilation of proposals, the FAA prepared a number of working documents for the Airworthiness Review Conference held in Washington, D.C., on December 2-11, 1974. The FAA distributed those documents to all persons who had participated in the Airworthiness Review Program and to all other interested persons who requested them (see Notice 74-5B, 39 FR 36594, October 11, 1974).
For reasons given in Notice 74-5B, not all of the proposals contained in the compilation were included in the agenda for the conference. However, the proposals not included in the agenda were listed in a conference workbook titled "Proposals Not in Agenda." In general, Notice 75-10 deals with the proposals identified as "Items for Notice" in that workbook.
On November 25, 1974, the FAA issued a notice of conference that set forth the schedule for the conference and invited all interested persons to attend the conference (see Notice 74-5C, 39 FR 41319, November 26, 1974).
The Airworthiness Review Conference was attended by over 586 individuals representing 22 foreign airworthiness authorities as well as aircraft manufacturers and users. Except for the opening and closing plenary sessions of the conference, one or more committees discussed agenda items during conference working hours. Summaries were given by the FAA Committee Chairmen at the close of discussions on each agenda item. Persons present were given an opportunity to correct those oral summaries. Transcripts of those summaries (with editorial revisions) were combined with an attendee list for the conference as well as with transcripts of certain plenary session speeches and were distributed in accordance with a notice on availability issued February 4, 1975 (see Notice 74-5D, 40 FR 5810; February 7, 1975).
In general this notice deals with the proposals that were contained in the Committee workbook titled "Committee V - Equipment". That workbook contained the proposals discussed by the Equipment and Systems Committee at the Airworthiness Review Conference. Another conference working document used was the Agenda for the Airworthiness Review Conference. That document, in addition to providing general information relating to the conference, included details on how the proposals were grouped into agenda items, and the scheduling of those items for discussion. Both the workbooks and the agenda were updated and corrected by a supplemental working document distributed prior to and at the conference to participating individuals as well as to other interested persons. These workbooks along with the committee discussions and written information submitted by conference attendees have provided the basis upon which the FAA has developed this notice.
A number of proposals contained in this notice were not included in the Committee V workbook. Among these are proposals that are directly related to the proposals in the workbook and are included for the sake of clarity, consistency, and comprehensiveness. In addition, there are several proposals dealt with in this notice which appeared as "Items for Notice" in the "Proposal Not in Agenda" workbook but were withheld from consideration pending the completion of the Airworthiness Review Conference (see Appendix I to Notice 75-10 for a list of those proposals).
A number of proposals contained in the Committee V workbook are not included in this notice. These proposals (listed in Appendices I, II, and III) fall into three categories as follows:
Appendix I - those proposals which are being deferred to a later notice or to the next Airworthiness or Operations Review.
Appendix II - those proposals which were withdrawn by their proponent.
Appendix III - those proposals which were removed from consideration during this Airworthiness Review.
The FAA believes that, in general, the proposals in Appendix I have sufficient merit to warrant further consideration and will be dealt with in the next Airworthiness or Operations Review, unless withdrawn by their proponent. But, because of the complexity of the proposal, the need for addition data, or the operational character of the proposal, further consideration within this Airworthiness Review is not feasible. The proposals in Appendix III have been removed from consideration for the reasons stated in that appendix.
The FAA believes that the airworthiness standards should, to the extent practical, be consistent throughout the airplane and rotorcraft certification parts (Parts 23, 25, 27, and 29). Therefore, the FAA has attempted within the time frame of this Airworthiness Review Program, to make consistent and parallel proposals, where appropriate, for each of these certification parts.
To avoid unnecessary repetition, in a number of instances the proposals developed for purposes of consistency are not set forth in their entirety if those proposals are substantively identical to another proposal in this notice. A short-form proposal referring to a proposal that is expressly set forth in this notice is used. Where a short-form proposal is used, however, there may be a need, if the proposal is to be adopted as a final rule, to change paragraph designations, cross references, or aircraft terminology (i.e. "airplane" to "rotorcraft", or vice versa) from that used in the referenced express proposal.
The FAA recognizes that there may exist additional instances in which a proposed rule change prescribed in this notice as expressly applying only to certain parts of the Federal Aviation Regulations should more appropriately apply to additional parts as well. Therefore, with respect to each proposal in this notice relating to Parts 23, 25, 27, or 29 of the Federal Aviation Regulations for which similar proposals do not exist for all of those parts, comments are solicited from all interested persons with respect to the applicability of that proposal (and its stated explanation) to those parts for which the proposal has not been expressly presented. Such comments received in response to this notice will either be dealt with as a part of the 1974 - 1975 Airworthiness Review Program or be considered as a part of the next Biennial Airworthiness Review.
For convenience, each proposal in this notice is numbered separately. The FAA requests that interested persons, when submitting comments, refer to proposals by these numbers, or by the section to which they relate. Each proposal contains, or references a proposal that contains, a reference to the Airworthiness Review Program proposal number, section, and agenda item to which that proposal relates. Comments on this notice should not refer to the Airworthiness Review Program proposal numbers or section numbers without also referring to the corresponding proposal numbers as set forth in this notice. Each proposal in this notice is provided with an explanation. In addition, to avoid confusion several of the proposals in this notice reference proposals in Notice 75-10 that deal with the same regulatory provisions. Several explanations deal with comments received in response to Notice 74-5A; however, all comments submitted in response to Notice 74-5A or submitted for the Airworthiness Review Conference, dealing with proposals contained in this notice, should be re-submitted if it is desired that they be considered as a part of this rulemaking action.
This amendment is proposed under the authority of Secs. 313(a), 601, 603, 604 and 605 of the Federal Aviation Act of 1958 (49 U.S.C. 1354(a), 1421, 1423, 1424, and 1425) and of Sec. 6(c) of the Department of Transportation Act (49 U.S.C. 1655(c)).

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The Proposed Amendment
In consideration of the foregoing, it is proposed to amend Parts 23, 25, 27, 29, 91, 121 and 127 of the Federal Aviation Regulations as follows:

PART 23 - AIRWORTHINESS STANDARDS: NORMAL, UTILITY, AND ACROBATIC CATEGORY AIRPLANES

5-1. By revising Sec. 23.1301 to read as follows:

Sec. 23.1301 Function and installation.
(a) Each item of installed equipment must -
(1) Be of a kind and design appropriate to its intended function;
(2) Be permanently and legibly marked or, if the item is too small to mark, tagged as to its identification, function, and operating limitations;
(3) Be installed according to limitations specified for that equipment; and
(4) Function properly when installed.
(b) No item of installed equipment may under any circumstance prevent the proper operation of any required system or of any other system provided to the flight crew for controlling, navigating, or monitoring performance of the airplane.

Explanation. This proposal would expand the applicability of this section to cover some optional equipment not now covered by present paragraph (a). Service experience has shown that improperly designed or malfunctioning optional equipment may introduce hazards. Proposed paragraph (a) is identical to the present requirement in Sec. 25. 1301 except for the clarification in proposed paragraph (a)(2). Proposed paragraph (b) would prohibit detrimental interference with required systems or any other system used in controlling, navigating or monitoring performance of the airplane. The addition of proposed paragraph (b) would render present Sec. 23.1309(a) superfluous. Therefore, it is also being proposed that Sec. 23.1309(a) be deleted.
Ref. Proposal No. 672; Sec. 12.1301; Agenda Item A-1.

Sec. 23.1309 [Amended]
5-2. By deleting Sec. 23.1309(a) and marking it "[Reserved]".
Explanation. See the proposal for Sec. 23.1301.
Ref. Proposal No. 672; Sec. 23.1301; Agenda Item A-1.

5-3. By revising Sec. 23.1321(a) and by adding a new Sec. 23.1321(e) to read as follows:

Sec. 23.1321 Arrangement and visibility.
(a) Each instrument which has a visual indicator for use in flight by any pilot must be plainly visible to him from his station with the minimum practicable deviation from his normal position and line of vision when he is looking forward along the flight path.
* * * * *
(e) If a visual indicator is provided to indicate malfunction of an instrument, it must be effective under all cockpit lighting conditions.

Explanation. The present visibility requirement in Sec. 23.1321(a) pertains only to flight, navigation, and powerplant instruments. Since other devices may be intended for use in flight and a pilot may develop vertigo by his head movements to see these devices, the location of all visual indicators for use in flight needs to be considered. Of course, flight safety will remain the primary consideration in position priority. The standard of "minimum practicable deviation" will remain, if the rule is adopted as proposed, thus allowing considerations of all factors related to utilization and flight safety. The same proposal is also made for Secs. 25.1321(a), 27.1321(a), and 29.1321(a).
The proposed Sec. 23.1321(e), if adopted, would extend the requirement of the present and proposed Sec. 23.1321(a) to require consideration of all possible cockpit lighting conditions for visibility of required malfunction indicators.
The FAA considered the question whether the proposal should apply only to required malfunction indicators or to all indicators, and believes that if a malfunction indicator has been provided for the crew it should be effective under all cockpit lighting conditions.
Ref. Proposal Nos. 680, 681, 791, 864, 950; Secs. 23.1321, 23.1321(a), 25.1321(b), 27.1321 , 29.1321; Agenda Items B-7, B-8.

5-4. By revising Sec. 23.1323 to read as follows:

Sec. 23.1323 Airspeed indicating system.
(a) Each airspeed indicating instrument must be calibrated to indicate true airspeed (at sea level with a standard atmosphere) with a minimum practicable instrument calibration error when the corresponding pitot and static pressures are applied.
(b) Each airspeed system must be calibrated in flight to determine the system error. The system error, including position error, but excluding the airspeed indicator instrument calibration error, may not exceed three percent of the indicated airspeed or five knots, whichever is greater, throughout the following speed ranges:
(1) 1.3 to VMO/MMO or VNE, whichever is appropriate with flaps retracted.
(2) 1.3 to VFE with flaps extended.

Explanation. See the proposal for Sec. 23.1545(a).
Ref. Proposal Nos. 114, 129; Secs. 23.1323(a), 23.1545(a); Agenda Item B-9.

5-5. By amending Sec. 23.1325 by adding paragraph (d) to read as follows:

Sec. 23.1325 Static pressure system.
* * * * *
(d) Each system must be designed and installed so that the error in indicated pressure altitude, at sea level, with a standard atmosphere, excluding instrument calibration error, does not result in an error of more than 30 feet per 100 knots speed for the appropriate configuration in the speed range between 1.3 with flaps extended and 1.8 with flaps retracted. However, the error need not be less than 30 feet.

Explanation. This proposal is identical to the standard presently required by Sec. 25.1325(e). Part 23 now contains no specified standard of allowable error for the static pressure system. This proposal, if adopted, will provide a standard which would be consistent for small airplanes and transport category airplanes.
Airworthiness Review Notice 75-10 proposed a new Sec. 23.1325(c).
Ref. Proposal No. 685; Sec. 23.1325; Agenda Item B-12.

5-6. By revising Sec. 23.1327(b), and by adding a new Sec. 23.1327(c), to read as follows:

Sec. 23.1327 Magnetic direction indicator.
* * * * *
(b) Except as provided in paragraph (c), the compensated installation may not have a deviation, in level flight, greater than ten degrees on any heading.
(c) A magnetic nonstabilized directional indicator may deviate more than ten degrees due to the operation of electrically powered systems such as electrically heated windshields if either an additional magnetic direction indicator (stabilized or nonstabilized) which does not have a deviation, in level flight, greater than ten degrees on any heading, or a gyroscopic direction indicator, is installed. Deviations of a magnetic nonstabilized direction indicator of more than 10 degrees must be placarded in accordance with Sec. 23.1547(e).

Explanation. This proposal would allow deviation (exceeding 10 degrees) in a magnetic nonstabilized direction indicator caused by operation of electrically powered systems if the airplane is equipped with another direction indicator that meets the standard specified in paragraph (b) and the airplane is placarded in accordance with proposed Sec. 23.1547(e). Under these conditions, safety would not be adversely affected. A similar change is proposed for Sec. 27.1327.
Ref. Proposal Nos. 686, 867; Secs. 23.1327(b), 27.1327(b); Agenda Item B-13.

5-7. By redesignating Sec. 32.1329 as Sec. 23.1311; and by revising the heading, by deleting the introductory phrase, by revising paragraph (a), and by adding new paragraphs (g) and (h) to read as follows:

Sec. 23.1311 Automatic flight control systems.
(a) Each automatic flight control system must be designed so that it can -
(1) Be quickly and positively disengaged by the pilots to prevent it from interfering with their control of the airplane; and
(2) Be sufficiently overpowered by one pilot to let him control the airplane. The overpower and control forces may not exceed the temporary application limits set forth in Sec. 23.143.
* * * * *
(g) Quick release (emergency) controls must be on each control wheel (or stick control) on the side opposite the throttles.
(h) Means independent of the mode selector switch must be provided to indicate to the flight crew the current mode of operation and the availability status of each alternate system.

Explanation. It is proposed that Sec. 23.1329 be redesignated as Sec. 23.1311, and that the term "automatic pilot system" be replaced with "automatic flight control system", as proposed for Part 25 in Airworthiness Review Notice No. 2 (Notice 75-10).
Under present Sec. 23.1329(a), either the airplane must have a means to quickly and positively disengage the automatic pilot system or one pilot must be able to overpower that system. The FAA believes that neither of these alternatives, by itself, provides an adequate level of safety. If a disengage device is provided, and a malfunction or failure in it prevents disengagement in an emergency, the pilot may not be able to overpower the automatic system. And if overpowering capability is provided, any need to continuously overpower the automatic flight control system adds a large increment to the pilot's workload and, should another failure occur, may prevent continued safe flight and landing. It is therefore proposed to require both a means to quickly and positively disengage the automatic flight control system and the ability to overpower that system. In addition, proposed Sec. 23.1311(a) would also require that the overpower and control forces may not exceed the temporary application limits set forth in present Sec. 23.143(c).
To ensure quick release of the automatic flight control system in an emergency, proposed Sec. 23.1311(g) would require that quick release controls be installed on each control wheel (or stick control), on the side opposite the throttles. This would allow disengagement without moving the hand from its normal position.
A proposal identical to Sec. 23.1311(a) is being proposed for Part 25. Also see the proposal for Secs. 27.1311 and 29.1311.
For an explanation of proposed Sec. 23.1311(h) see the proposal for Sec. 25.1329(h).
Ref. Proposal No. 687; Sec. 23.1329(a)(1); Agenda Item C-20.

5-8. By revising Sec. 23.1335, including the heading, to read as follows:

Sec. 1335 Flight director systems.
If a flight director system is installed, means independent of the mode selector switch must be provided to indicate to the flight crew its current mode of operation.

Explanation. See the proposal for Sec. 25.1335.
A proposal was made in Airworthiness Review Notice No. 2 (Notice 75-10) to delete present Sec. 23.1335. This Notice No. 2 proposal was not included in the agenda for the Airworthiness Review Conference. At the conference, however, proposals concerning flight director systems were discussed, and have been included in this notice as a proposal for Sec. 25.1335. Pursuant to FAA's belief that the airworthiness standards should be consistent, to the extent practicable, throughout the airplane and rotorcraft certification parts new proposals for Secs. 23.1335, 27.1335 and 29.1335 are being made. The proposal contained in Notice No. 2 for Sec. 23.1335 will be withdrawn at the time of final rulemaking action if the new proposal for Sec. 23.1335 is adopted. All comments received in response to proposed Sec. 23.1335 in Notice No. 2 will be considered for this new proposal for Sec. 23.1335.
Ref. Proposal No. 141; Sec. 25.1333; Agenda Item C-23.

5-9. By adding a new Sec. 23.1351(f) to read as follows:

Sec. 23.1351 General.
* * * * *
(f) External power. If provisions are made for connecting external power to the airplane, and that external power is not used solely for starting the engine, means must be provided to ensure that no external power supply having a reverse polarity, or a reverse phase sequence, can supply power to the airplane's electrical system.

Explanation. If an external power supply with reverse polarity or reverse phase sequence were to supply power to the airplane's electrical system extensive damage to the system could result. This proposal would require a means to prevent such an occurrence.
Ref. Proposal Nos. 118, 308; Secs. 23.1351, 25.1355; Agenda Item D-29.

5-10. By revising Sec. 23.1353(b)(1) and by adding a new Sec. 23.1353(g) to read as follows:

Sec. 23.1353 Storage battery design and installation.
* * * * *
(b) * * *
(1) At maximum regulated voltage or power;
* * * * *
(g) Each nickel cadmium battery installation capable of being used to start an engine or auxiliary power unit must have provisions to prevent any hazardous effect on structure or essential systems that may be caused by the maximum amount of heat the battery can generate during a short circuit of the battery or of its individual cells.

Explanation. Proposed Sec. 23.1353(b)(1) would add "or power" to the battery recharging standard. The proposal by adding an alternative standard is intended to clarify the present rule to more appropriately include all battery charging means and parameters. In some battery charging techniques, voltage is not a controlled factor except by response of the battery. Also, power is a measure of heat input to the battery. A similar proposal is made for Secs. 25.1353(c)(1)(i), 27.1353(b)(1), and 29.1353(c)(1)(i).
Short circuits of nickel cadmium batteries (either internally or to the airplane structure through the battery caps) have occurred in service. The heat generated by such short circuits may in some circumstances damage nearby structure or essential systems. It is therefore proposed to require provisions to prevent any hazardous effect from this cause. See also proposed new Sec. 23.1353(f) in Airworthiness Review Notice No. 2 (Notice 75-10), which is aimed at reducing the occurrence of short circuits that are caused by excessive battery charging current.
Ref. Proposal Nos. 307, 694, 800, 871, 956; Secs. 23.1353(f), 25.1353, 25.1353(d), 27.1353(f), 29.1353(d); Agenda Items D-30, D-31.

5-11. By revising Sec. 23.1357(b) to read as follows:

Sec. 23.1357 Circuit protective devices.
* * * * *
(b) A protective device for a circuit essential to flight safety may not be used to protect any other circuit.
* * * * *

Explanation. Proposed paragraph (b) would clarify the present rule by specifically prohibiting the use of a single protective device to protect an essential and a nonessential circuit, or more than one essential circuit. A protective device protecting two circuits would trip in response to a fault in either one; thus a fault in the nonessential circuit would render the essential circuit inoperative.
Ref. Proposal Nos. 695, 872, 119; Secs. 23.1357(b), 27.1357(b); Agenda Item D-32.

Sec. 23.1361 [Amended]
5-12. By amending Sec. 23.1361(b) by adding, at the end thereof, the sentence, "These circuits must be isolated, or physically shielded, to prevent their igniting flammable fluids or vapors that might be liberated by the leakage or rupture of flammable fluid systems".

Explanation. Circuits by-passing the master switch remain energized after the master switch is opened. If such circuits fail during a crash landing they might possibly ignite nearby flammable fluids or vapors. This proposal would reduce that possibility.
Ref. Proposal No. 696; Sec. 23.1361(b); Agenda Item D-34.

Sec. 23.1401 [Amended]
5-13. By amending Sec. 23.1401 by striking the number "30" in both places in paragraph (b) and inserting in place thereof (in both places) the number "75"; and by adding a line at the end of the table in paragraph (f) to read as follows: "30 to 75 ______20".

Explanation. The present anticollision light rule in Sec. 23.1401(b) requires that the field of coverage extend in each direction within at least 30 above and 30 below the horizontal plane of the airplane. The FAA believes that this minimum coverage should be increased. Under the present rule, visibility of the light may be less than is needed when the airplane is approached by another aircraft ascending or descending, or when the airplane is banked at more than 30. This proposal would expand the present field of coverage so that it extends in each direction within at least 75 above and 75 below the horizontal plane of the airplane. In addition, this proposal would specify at least a 20-candle effective intensity in the 30 to 75 field of coverage, thereby increasing the probability of seeing the airplane from other aircraft (including air rescue aircraft) and from control towers.
Ref. Proposal Nos. 124, 697, 313, 801; Secs. 23.1401(b), 23.1401(f), 25.1401(b), 25.1401(f); Agenda Item E-36.

5-14. By adding a new Sec. 23.1438 to read as follows:

Sec. 23.1438 Pressurization and pneumatic systems.
(a) Pressurization system components must be burst pressure tested to 2.0 times, and proof pressure tested to 1.5 times, the maximum normal operating pressure.
(b) Pneumatic system components must be burst pressure tested to 4.0 times, and proof pressure tested to 1.5 times, the maximum normal operating pressure.

Explanation. Components (such as ducts and couplings) of pressurization and pneumatic systems have failed at an unacceptable rate in service. The proposed standards for these components have been effective in preventing design deficiencies in the past.
Ref. Proposal Nos. 702, 811; Secs. 23.1438(a)(b)(c)(d), 25.1438; Agenda Item G-45.

5-15. By adding a new Sec. 23.1447(c) and (d) to read as follows:

Sec. 23.1447 Equipment standards for oxygen dispensing units.
* * * * *
(c) If certification for operation above 30,000 feet is requested, the dispensing units providing the required oxygen flow rate must be automatically presented to each occupant before the cabin pressure altitude exceeds 14,000 feet.
(d) If an automatic dispensing unit (hose and mask, or other unit) system is installed, each occupant served by that system must be provided with a manual means to make the dispensing unit immediately available in the event of failure of the automatic system.

Explanation. The proposal would require automatic presentation of oxygen dispensing units on airplanes certificated under Part 23 for operations above 30,000 feet. Should loss of pressurization occur at those altitudes, the time of useful consciousness varies between 90 seconds at 30,000 feet and 10-12 seconds at 40,000 feet, necessitating automatic presentation of oxygen dispensing units. It is also proposed to specify 14,000 feet as the cabin pressure altitude at which they must be automatically presented so that they would be ready for use not only when the cabin pressure altitude goes very rapidly to very high values but also in the event of a pressurization system failure or malfunction after which (under present Sec. 23.841(a)) the cabin pressure altitude may go to 15,000 feet. The 14,000-foot cabin pressure altitude for automatic presentation is also being proposed for Part 25.
In addition, since service experience has shown that the automatic presentation feature may fail, it is proposed that a manual means be provided to enable each occupant to gain access to his oxygen dispensing unit. This manual means is also being proposed for Part 25.
Ref. Proposal Nos. 704, 322; Secs. 23.1447(c) and (d), 25.1447(c)(1); Agenda Item H-47.

Sec. 23.1450 [New]
5-16. By adding a new Sec. 23.1450 that would be substantively identical to the proposed new Sec. 25.1450.

Sec. 23.1461 [New]
5-17. By adding a new Sec. 23.1461, following Sec. 23.1449, that would be substantively identical to the proposed new Sec. 25.1461.

5-18. By revising Sec. 23.1545(a) and Sec. 23.1545(b)(5), and by adding Sec. 23.1545(b)(6), to read as follows:

Sec. 23.1545 Airspeed indicator.
(a) Each airspeed indicator must be marked as specified in paragraph (b) of this section, with the marks located at the corresponding indicated airspeeds.
(b) * * *
(5) For the one-engine-inoperative best rate of climb speed, VY, a blue sector extending from the VY speed at sea level to the VY speed at -
(i) An altitude of 5000 feet, if the one-engine-inoperative best rate of climb at that altitude is less than 100 feet per minute; or
(ii) The highest 1000-foot altitude (at or above 5000 feet ) at which the one-engine-inoperative best rate of climb is 100 feet per minute or more.
Each side of the sector must be labeled to show the altitude for the corresponding VY.
(6) For the minimum control speed (one-engine-inoperative), VMC, a red radial line.

Explanation. Proposed Sec. 23.1545(a) would require airspeed limitation marks be located at the corresponding indicated airspeeds instead of at the calibrated airspeeds, thereby providing a more useful indicator dial for operation of the airplane. However, to ensure uniformity, it is also proposed to revise Sec. 23.1323 to require that the airspeed instrument be calibrated according to the standard relationship between pressure and airspeed. (See the proposal for Sec. 23.1323.) The allowable airspeed system error would then include position error, but exclude the airspeed instrument calibration error, consistent with Part 25. The airspeed range for calibration, as set forth in proposed Sec. 23.1323, would encompass the airspeed limitations in proposed Sec. 23.1545(a).
Also, proposed Sec. 23.1545(b)(5) would provide for the variation in the one-engine-inoperative best rate of climb speed with altitude, and proposed Sec. 23.1545(b)(6) would cover VMC.
Ref. Proposal Nos. 114, 129; Secs. 23.1323(a), 23.1545(a); Agenda Item B-9.

5-19. By adding a new Sec. 23.1547(e) to read as follows:

Sec. 23.1547 Magnetic direction indicator.
* * * * *
(e) If a magnetic nonstabilized direction indicator can have a deviation of more than 10 degrees caused by electrical equipment, the placard must state which electrical loads, or combination of loads, would cause a deviation of more than 10 degrees when turned on.

Explanation. See the proposal for Sec. 23.1327(b) and (c). Proposed Sec. 23.1547(e) would require that the magnetic direction indicator placard identify those electrical loads which cause a deviation of more than 10 degrees. The pilot would thus know when the indicated heading of the magnetic nonstabilized direction indicator is not reliable due to magnetic fields associated with airplane electrical systems.
Ref. Proposal Nos. 686, 867; Secs. 23.1327(b), 27.1327(b); Agenda Item B-13.

PART 25 - AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

5-20. By revising Sec. 25.831(e) and by adding a new Sec. 25.831(f) to read as follows:

Sec. 25.831 Ventilation.
* * * * *
(e) Except as provided in paragraph (f) of this section, there must be a means in each compartment or area occupied by crewmembers to enable the occupants of each area or compartment to control the temperature and quantity of ventilating air supplied to that compartment or area independently of the temperature and quantity of air supplied to other compartments or areas.
(f) Means to control the temperature and ventilating air flow in the crew compartment independently of the temperature and air flow in the passenger compartment are not required if all of the following conditions are met;
(1) The total volume of the crew and passenger compartments is 800 cubic feet or less.
(2) The air inlets and passages for air to flow between crew and passenger compartments are arranged to provide compartment temperatures within 5F of each other and adequate ventilation to occupants in both compartments.
(3) The temperature and ventilation controls are accessible to the pilot.

Explanation. A proposal was made in Airworthiness Review Notice No. 2 (Notice 75-10) to revise Sec. 25.831(e) and to add a new Sec. 25.831(f). These proposals were not included in the agenda for the first Airworthiness Review Conference. At the conference, however, other proposals concerning Sec. 25.831(e) were discussed. The FAA now believes that a further revision of Sec. 25.831(e) may be needed. Also, the proposed new Sec. 25.831(f) is reproposed to avoid confusion with Notice No. 2. The proposals contained in Notice No. 2 for Sec. 25.831 for Sec. 25.831 will thus be withdrawn at the time of final rulemaking action if the proposal for Sec. 25.831 in this Notice is adopted. All comments received in response to the proposal for Sec. 25.831 in Notice No. 2 will be considered for the new proposal for Sec. 25.831.
The proposed new Sec. 25.831(f) would allow an exception to the requirement of independent controls for ventilating air for certain airplanes. If the conditions in new paragraph (f) are met, the FAA believes independent controls do not contribute significantly to airworthiness. However, the FAA believes if those conditions are not met that greater control in individual areas may be needed.
Neither present Sec. 25.831(e) nor proposed Sec. 25.831(e) in Notice No. 2 requires independent control in flight attendant areas of ventilating air supplied to those areas. Since both flight attendants and flight crewmembers perform various duties affecting safety, it is necessary that the ventilation in their work areas be adequate to ensure that their efficiency is not adversely affected. The ventilation needed in flight attendant areas may be quite different due to the presence of heating elements and the activity required in performance of their duties. Control of ventilation in flight attendant areas may be needed when flight crewmembers are busy with other tasks. Therefore, the FAA believes that all crewmembers compartments or areas should have not only their own supply of ventilating air, but should have a control of such air in the individual compartment or area.
Ref. Proposal Nos. 251, 729; Secs 25.831, 25.831(f); Agenda Item G-42.

5-21. By revising Sec. 25.1301(b) to read as follows:

Sec. 25.1301 Function and installation.
* * * * *
(b) Be permanently and legibly marked or, if the item is too small to mark, tagged as to its identification, function, and operating limitations;
* * * * *

Explanation. The proposal would provide a more realistic and specific requirement for labeling airplane equipment. The proposal is consistent with the corresponding requirement for equipment manufactured in accordance with a Technical Standard Order and with the proposal for Sec. 23.1301.
Ref. Proposal No. 781, Sec. 25.1301; Agenda Item A-1.

5-22. By amending the lead-in of Sec. 25.1309(d) and (e) and by revising Sec. 25.1309(a), (b), (c), (e)(3) and (f) to read as follows:

Sec. 25.1309 Equipment systems and installations.
(a) The equipment, systems, and installations whose functioning is required by this chapter must be designed to ensure that they perform their intended functions under any foreseeable operating condition.
(b) The airplane systems and associated components, considered separately and in relation to other systems, must be designed so that -
(1) The occurrence of any failure condition which would prevent the continued safe flight and landing of the airplane or which, in the event of loss of all propulsive power, would preclude controlled flight to an emergency landing, is extremely improbable; and
(2) The occurrence of any other failure condition which would significantly reduce the operational or performance capability of the airplane is improbable.
(c) Warning information must be provided to alert the crew to unsafe system operating conditions, and to enable them to take appropriate corrective action. Systems, controls, and associated monitoring and warning means must be designed to minimize crew errors which could create additional hazards.
(d) Compliance with the requirements of paragraph (b) of this section must be shown by analysis, and where necessary, by appropriate ground, flight, or flight simulator tests. The analysis must consider -
* * * * *
(e) Each installation whose functioning is required by this chapter, and that requires a power supply, is an "essential load" on the power supply. * * *
(3) Essential loads after failure of -
(i) Any one engine on two-engine airplanes; and
(ii) Any two engines on three-or-more engine airplanes.
(f) In determining compliance with paragraphs (e)(2) and (3) of this section, the power loads may be assumed to be reduced under a monitoring procedure consistent with safety in the kinds of operation authorized. Loads not required in controlled flight need not be considered for the two-engine-inoperative condition on airplanes with three or more engines.
* * * * *

Explanation. The proposed revision of Sec. 25.1309(a) and the lead-in paragraph (e) would change the term "subchapter" to "chapter" in both. The term "chapter" is being proposed to broaden the applicability of Sec. 25.1309. Equipment, systems, and installations not specifically required by Subchapter C are installed in airplanes in order to engage in operations covered by other subchapters. Dependence for safety of flight might be placed on installations not otherwise mentioned in the rules. The proposal for Sec. 25.1309(a) is also made for Sec. 27.1309(a) and Sec. 29.1309(a).
The proposal for Sec. 25.1309(b) would qualify the present requirement in Sec. 25.1309(b)(1) to take into account the possibility of loss of all propulsive power, in which event "continued safe flight and landing" would not necessarily be attainable. In addition, the proposal would delete the reference to occupant injury in present Sec. 25.1309(b)(2) since the matter of preventing injuries to occupants is treated elsewhere in the regulations (see Secs. 25.785, 25.787, 25.789, 25.801), and would clarify the language in that paragraph.
Also the proposal would revise the language in present Sec. 25.1309(c) and delete the reference to paragraph (c) from the language of paragraph (d). The method of compliance set forth in paragraph (d) which is applicable to paragraph (c) in the present rule has been found to be an unreasonably burdensome procedure in some instances. Further, the revision of paragraph (c) would more appropriately emphasize the required design considerations of minimizing crew errors.
Under present Sec. 25.1309(e)(3), system power sources on three-engine airplanes need not be capable of supplying essential loads after failure of two engines. It is proposed to upgrade this requirement by specifying that essential loads must be supplied after failure of two engines on three-engine airplanes. In general, three-engine airplanes are capable of considerable performance on one engine. Essential loads required for controlled flight on one engine must be supplied. A corresponding change has been proposed for Sec. 25.1309(f).
A proposal in Airworthiness Review Notice Number 2 (Notice 75-10) would add commas in the section heading between "Equipment" and "systems," and between "systems" and "and."
Ref. Proposal Nos. 295, 296, 299, 789; Secs. 25.1309, 25.1309(a), 25.1309(e); Agenda Items A-2, A-3, A-6.

Sec. 25.1321 [Amended]
5-23. By amending Sec. 25.1321 in a manner substantively identical to that proposed for Sec. 23.1321.

5-24. By revising the title of Sec. 25.1329 and 25.1329(a), and by adding a new Sec. 25.1329(h) to read as follows:

Sec. 25.1329 Automatic flight control systems.
(a) Each automatic flight control system must be designed so that it can -
(1) Be quickly and positively disengaged by the pilots to prevent it from interfering with their control of the airplane; and
(2) Be sufficiently overpowered by one pilot to let him control the airplane. The overpower and control forces may not exceed the temporary application limits set forth in Sec. 25.143.
* * * * *
(h) Means independent of the mode selector switch must be provided to indicate to the flight crew the current mode of operation and the availability status of each alternative system.

Explanation. For an explanation of Sec. 25.1329(a), see the proposal for Sec. 23.1329 (proposed redesignation to Sec. 23.1311).
Service experience has shown that where automatic flight control systems are installed, confusion may result if there is no indication of the current mode of operation, and of the status of alternate systems. Moreover, experience has also shown that the position of a mode selector switch is not a reliable means of providing such indication. This proposal would ensure that an indication entirely independent of the mode selector switch is provided.
In Airworthiness Review Notice Number 2 (Notice 75-10), a proposal was made to change all references from "Automatic Pilot systems" to "Automatic flight control systems", and this proposal has been worded to be consistent with that proposal. The proposal in Notice 75-10 would also redesignate Sec. 25.1329 as Sec. 25.1311. This proposal (for Sec. 25.1329(h)), if adopted, will be designated accordingly.
Ref. Proposal Nos. 687, 795, Secs. 23.1329(a)(1), 25.1329(h); Agenda Items C-20, C-22.

5-25. By amending Sec. 25.1331 by striking the phrase ", or adjacent to," in paragraph (a)(1); and by adding a new paragraph (a)(3) to read as follows:

Sec. 25.1331 Instruments using a power supply.
(a) * * *
(3) If in instrument presenting navigation data receives information from sources external to that instrument and loss of that information would render the presented data unreliable, the instrument must incorporate a visual means to warn the crew, when such loss of information occurs, that the presented data should not be relied upon.

Explanation. By deleting the alternative "adjacent to" location from instrument power failure indicators, this proposal would require that these indicators be integral with the instrument. An integral indicator provides a more reliable warning of instrument-power failure. The proposal for paragraph (a)(3) would ensure that the flight crew is warned when loss of information to an instrument presenting navigation data renders that data unreliable.
Ref. Proposal No. 796; Sec. 25.1331(a)(c); Agenda Item B-15.

5-26. By striking the period at the end of Sec. 25.1333(a) and inserting a semicolon in place thereof, and by revising Sec. 25.1333(b) to read as follows:

Sec. 25.1333 Instrument systems.
* * * * *
(b) The equipment, systems, and installations must be designed so that one display of the information essential to the safety of flight which is provided by the instruments, including attitude, direction, airspeed, and altitude will be immediately available to the pilots after any single failure or combination of failures that is not shown to be extremely improbable; and
* * * * *

Explanation. A major revision to Sec. 25.1333 was made by Amendment 25-23, effective May 8, 1970 (35 FR 5665). The FAA still believes, as stated in Amendment 25.23, that instrument systems must be designed considering a combination of failures that are not shown to be extremely improbable and the necessity of providing information essential to the safety of flight to any pilot after these failures. However, the FAA believes that the requirement in present Sec. 25.1333(b) of availability of this information without crewmember action is too restrictive. Some minimal crewmember action, such as allowing manual switching, would be a more reasonable alternative without degrading the level of safety. Therefore, it is proposed to delete the words "without additional crewmember action" and "remain", and to insert "will be immediately" available.
Ref. Proposal No. 303; Sec. 25.1333(a) and (b); Agenda Item B-14.

5-27. By adding a new Sec. 25.1335 to read as follows:

Sec. 25.1335 Flight director systems.
If a flight director system is installed, means independent of the mode selector switch must be provided to indicate to the flight crew its current mode of operation.

Explanation. Service experience has shown that safety is compromised when the flight crew is not informed as to the current mode of operation of the flight director system. Moreover, experience has also shown that the position of the mode selector switch is not a reliable means of providing that information. This proposal would ensure that an indication entirely independent of the mode selector switch is provided.
Ref. Proposal No. 141; Sec. 25.1333; Agenda Item C-23.

5-28. By adding a new Sec. 25.1351(c) that would be substantively identical to the proposed new Sec. 23.1351(f) and by adding a new Sec. 25.1351(d) to read as follows:

Sec. 25.1351 General.
* * * * *
(d) Operation without normal electrical power. It must be shown by analysis, tests, or both, that the airplane can be operated safely in VFR conditions, for a period of not less than five minutes, with the normal electrical power inoperative, with critical type fuel (from the standpoint of flameout and restart capability), and with the airplane initially at the maximum certificated altitude. Parts of the electrical system may remain on if -
(1) A single malfunction, including a wire bundle or junction box fire, cannot result in loss of the part turned off and the part turned on;
(2) The parts turned on are electrically and mechanically isolated from the part turned off; and
(3) The electrical wire and cable insulation, and other materials, of the parts turned on are self-extinguishing when tested in accordance with Sec. 25.1359(d).

Explanation. The FAA has been applying for the past few years, as a special conditions, a requirement that the airplane can be operated safely for a period of five minutes under VFR conditions without normal generator or battery power. Emergency power should be provided to those services which are necessary to complete the flight in safety. Such emergency power should be mechanically and electrically isolated from the normal system and be such that no single malfunction, including the cutting of a cable bundle or the loss of a junction box, will affect both the normal and emergency power.
Ref. Proposal No. 798; Sec. 25.1351(c); Agenda Item D-24.

Sec. 25.1353 [Amended]
5-29. By adding a new Sec. 25.1353(c)(1) (i) and (c)(6) that would be substantively identical to the proposed new Sec. 23.1353 (b)(1) and (g).

Sec. 25.1401 [Amended]
5-30. By amending Sec. 25.1401(b) and (f) in a manner substantively identical to that proposed for Sec. 23.1401(b) and (f), respectively.

5-31. By adding a new Sec. 25.1421, following Sec. 25.1419, to read as follows:

Sec. 25.1421 Megaphones.
(a) If a megaphone is installed, the megaphone must be so protected that it will perform its function after being subjected to the ultimate inertia forces specified in Sec. 25.651(b)(3).
(b) Each compartment used for megaphone stowage must be conspicuously marked - "MEGAPHONE".

Explanation. Although Sec. 121.309(f) prescribes megaphones, there are no corresponding airworthiness standards covering their installation. The proposal would add airworthiness standards in Part 25 dealing with the ability of the megaphone installation to withstand emergency landing loads, and with the marking of megaphone stowage compartments, thereby providing additional assurance that it is serviceable, and can be located, in an emergency.
Ref. Proposal No. 806; Sec. 25.1421; Agenda Item J-58.

5-32. By amending Sec. 25.1435 by striking the language in Sec. 25.1435(a)(3) and in place thereof inserting the term "[Reserved]"; by revising Sec. 25.1435(a)(2) and (a)(4)(ii), and by adding a new Sec. 25.1435(a)(7) and (a)(8), to read as follows:

Sec. 25.1435 Hydraulic systems.
(a) * * *
(2) A system pressure gage and a fluid quantity gage, both located at a flight crewmember station, must be provided for each hydraulic system that -
(i) Performs a function that is essential for continued safe flight and landing; or
(ii) In the event of hydraulic system malfunction, requires corrective action by the crew to ensure continued safe flight and landing.
* * * * *
(4) * * *
(ii) Except as provided in paragraph (a)(7) of this section, will not exceed 125 percent of the design operating pressure, excluding pressure at the outlets specified in paragraph (a)(4)(i) of this section. Design operating pressure is the maximum steady operating pressure.
* * * * *
(7) Transient pressure in a part of the system may exceed the limit specified in paragraph (a)(4)(ii) of this section if -
(i) A survey of those transient pressures is conducted to determine their magnitude and frequency; and
(ii) Based on the survey, the fatigue strength of that part of the system is substantiated by analysis or tests, or both.
(8) Each hydraulic pump must be designed and installed so that loss of hydraulic fluid to the pump cannot create a hazard that might prevent continued safe flight and landing.
* * * * *

Explanation. The term "continuously operating system" in present Sec. 25.1435(a)(2) and (a)(3) is not sufficiently definitive, nor is it clear whether the "means to indicate" system pressure and fluid quantity must necessarily be a gage. The proposal would identify those hydraulic systems for which a means to indicate system pressure and fluid quantity must be provided, and would require specifically that, for such systems, the means be a gage.
Present Sec. 25.1435(a)(4)(ii) does not allow for transient pressures which, although taken into account in the design of the hydraulic system, exceed the prescribed limit. The FAA believes, after further study of this issue in the light of recent service experience, that if the magnitude and frequency of such transient pressures in some part of the system were determined by survey, and the fatigue strength of this part of the system were substantiated on the basis of that survey, safety would not be adversely affected, nor would system performance be reduced significantly. The proposed revision to Sec. 25.1435(a)(4)(ii) and proposed new Sec. 25.1435(a)(7) would remove this restriction on design.
Service experience has shown that hydraulic fluid to hydraulic pumps may be lost, after which the pump continues to rotate, overheats, and disintegrates. Proposed Sec. 25.1435(a)(8) would require that no hazard preventing continued safe flight and landing results after loss of such hydraulic fluid.
Ref. Proposal No. 319, 808, 809; Secs. 25.1435(a), 25.1435(a)(4), 25.1435(d)(e)(f); Agenda Items F-39, F-41.

Sec. 25.1438 [Amended]
5-33. By adding a new Sec. 25.1438 that would be substantively identical to proposed new Sec. 23.1438.

5-34. By revising Sec. 25.1447(c)(1) and (c)(2) to read as follows:

Sec. 25.1447 Equipment standards for oxygen dispensing units.
* * * * *
(c) * * *
(1) There must be an oxygen dispensing unit connected to oxygen supply terminals immediately available to each occupant, wherever seated. If certification for operation above 30,000 feet is requested, the dispensing units providing the required oxygen flow must be automatically presented to the occupants before the cabin pressure altitude exceeds 14,000 feet. Each occupant served by the automatic dispensing unit system must be provided with a manual means to make the dispensing unit immediately available in the event of failure of the automatic system. The total number of dispensing units and outlets must exceed the number of seats by at least 10 percent. The extra units must be as uniformly distributed throughout the cabin as practicable.
(2) Each flight crewmember on flight deck duty must be provided with demand equipment. In addition, each flight crewmember must be provided with a quick-donning type of oxygen dispensing unit, connected to an oxygen supply terminal, that is immediately available to him when seated at his station, and that is designed and installed so that it -
(i) Can be placed on the face from its ready position, properly secured, sealed, and supplying oxygen upon demand, with one hand within five seconds, and without disturbing eyeglasses or causing delay in proceeding with emergency duties; and
(ii) Allows, while in place, the performance of normal communication functions.
* * * * *

Explanation. For an explanation of Sec. 25.1447(c)(1) see the proposal for new Sec. 23.1447(c) and (d).
Present Sec. 25.1447(c)(2) requires that oxygen dispensing units be "immediately available" to search flight crewmember when seated at his station, but does not define that term. The proposal, which uses the language in present Sec. 121.333(c)(2), would provide a basis for approving oxygen dispensing units that must be "immediately available" in the event of rapid depressurization.
Ref. Proposal Nos. 322, 704, 815; Secs. 23.1447(c) and (d), 25.1447(c)(1), 25.1447 (c)(2); Agenda Items H-47, H-49.

5-35. By adding a new Sec. 25.1450 to read as follows:

Sec. 25.1450 Chemical oxygen generators.
(a) For the purpose of this section, a chemical oxygen generator is defined as a device which produces oxygen by chemical reaction.
(b) Each chemical oxygen generator must be designed and installed in accordance with the following requirements:
(1) Surface temperature developed by the generator during operation may not create a hazard to the airplane or to its occupants.
(2) Means must be provided to -
(i) Indicate positively that oxygen is flowing; and
(ii) Relieve any internal pressure that may be hazardous.
(c) Each portable chemical oxygen generator that is capable of sustained operation by successive replacement of a generator element must be designed to meet the following requirements in addition to those in paragraph (b);
(1) The generator must be placarded to show -
(i) The rate of oxygen flow, in liters per minute;
(ii) The duration of oxygen flow, in minutes, for the replaceable generator element; and
(iii) A warning that the replaceable generator element may be hot, unless the element construction is such that the surface temperature cannot exceed 100F.
(2) Means must be provided for safe replacement and stowage of used generator elements.

Explanation. Chemical oxygen generators have been in use for some time. This proposal would require that they be designed and installed in accordance with specified safety standards derived from service experience.
Ref. Proposal Nos. 705, 816; Secs. 23.1450, 25.1450; Agenda Item H-50.

5-36. By revising Sec. 25.1457(b), (d)(1), (e) and (g) to read as follows:

Sec. 25.1457 Cockpit voice recorders.
* * * * *
(b) The recording requirements of paragraph (a)(2) of this section must be met by installing two directional microphones and, if necessary, an area microphone. The microphones must be located in the cockpit so that -
(1) One directional microphone is directed toward the captain and the other toward the first officer;
(2) The intelligibility of the recorded communications is as high as practicable under flight cockpit noise conditions.
* * * * *
(d) Each cockpit voice recorder must be installed so that -
(1) It receives its electric power from a bus that supplies emergency loads;
* * * * *
(e) The record container must be located and mounted to minimize the probability of rupture of the container as a result of crash impact and consequent heat damage to the record from fire. If the record is on tape, the tape must be stored on a reel, or stored by any other method that is equivalent to storage on a reel with respect to providing protection against damage by crash impact or heat exposure. In meeting this requirement, the record container must be as far aft as practicable, but may not be where aft mounted engines may crush the container during impact. However, it need not be outside the pressurized compartment.
* * * * *
(g) Each record container must -
(1) Be either bright orange or bright yellow;
(2) Have reflective tape affixed to its external surface to facilitate its location under water; and
(3) Have an underwater locating device, when required by the operating rules of this chapter, on or adjacent to the container which is secured in such manner that they are not likely to be separated during crash impact.

Explanation. Present Sec. 25.1457(b) prescribes a cockpit-mounted area microphone for recording voice communications of flight crewmembers on the flight deck. To improve the intelligibility of the voice record, and to provide more positive voice identification, it is proposed to require at least two directional microphones (one directed toward each pilot at his duty station). If these directional microphones are not sufficient to comply with Sec. 25.1457(a)(2), an additional area microphone would be required. Also, some other provisions of Sec. 25.1457(b) are being deleted to allow flexibility of design.
Present Sec. 25.1457(d)(1) requires that the cockpit voice recorder receive its electrical power from the bus that provides maximum reliability without jeopardizing service to "essential or emergency loads". The result has been that the cockpit voice recorder is usually connected to a bus which may be rendered inoperative by malfunctions within the electrical system itself. To ensure that the cockpit voice recorder receives power in that event, proposed Sec. 25.1457(a)(1) would require that if receive its electric power from a bus that supplies emergency loads.
The proposed revision to Sec. 25.1457(e) would require, if the voice record is on tape, that the tape be stored on a reel, or by an equivalent method with respect to protection against damage by crash impact or heat exposure. Information has been lost from tapes stored in random fashion due to crushing and folding of the tape when exposed to high deceleration forces.
For explanation of paragraph (g), see the proposal for Sec. 121.359.
Ref. Proposal Nos. 324, 325, 817; Sec. 25.1457; Agenda Items I-54, I-55, I-56.

5-37. By amending Sec. 25.1459 by deleting paragraph (a)(7); and by revising Sec. 25.1459(a)(4) and (d) to read as follows:

Sec. 25.1459 Flight recorders.
(a) Each flight recorder required by the operating rules of this chapter must be installed so that -
* * * * *
(4) There is a means for preflight checking of the recorder for proper operation.
* * * * *
(d) Each record container must -
(1) Be either bright orange or bright yellow;
(2) Have reflective tape affixed to its external surface to facilitate its location under water; and
(3) Have an underwater locating device when required by the operating rules of this chapter, on or adjacent to the container which is secured in such a manner that they are not likely to be separated during crash impact.

Explanation. The proposal for Sec. 25.1459(a)(4) is intended to promote the availability of information from the flight record. The present requirement includes checking the recorder from proper tape movement which is not a sufficient indication that the recorder is capable of actually recording. Information available to the FAA indicates that there are presently devices available which can check this capability.
The proposal for Sec. 25.1459(d) would make the applicable flight recorder requirements consistent with those proposed for cockpit voice recorders. However, the only additional requirement proposed for this section is the provision for reflective tape.
Ref. Proposal Nos. 325, 534, 818; Sec. 25.1457, 25.1459(a)(4), 121.343; Agenda Items I-52, I-53, I-55.

5-38. By adding a new Sec. 25.1461, following Sec. 25.1459, to read as follows:

Sec. 25.1461 Equipment containing high energy rotors.
(a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section.
(b) High energy rotors contained in equipment must be able to withstand damage caused by malfunctions, vibration, abnormal speeds, and abnormal temperatures. In addition -
(1) Auxiliary rotor cases must be able to contain damage caused by the failure of high energy rotor blades; and
(2) Equipment control, devices, systems, and instrumentation must reasonably ensure that no operating limitations affecting the integrity of high energy rotors will be exceeded in service.
(c) It must be shown by test that equipment containing high energy rotors can contain any failure of a high energy rotor that occurs at the highest speed obtainable with the normal speed control devices inoperative.
(d) Equipment containing high energy rotors must be located where rotor failure will neither endanger the occupants nor adversely affect continued safe flight.

Explanation. This proposal would add requirements for protection against the failure of equipment containing high energy rotors, such as turbine engine starters, air cycle machines, and certain cooling fans. Experience has shown that failures which release the energy stored in these rotors may result in engine or structural damage, fires, or injury to occupants. The language in this proposal is identical to Secs. 27.1461 and 29.1461.
Ref. Proposal Nos. 771, 810, 701; Secs. 25.1167, 25.1436, 23.1436; Agenda Item J-67.

PART 27 - AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT

5-39. By revising Sec. 27.1301 to read as follows:

Sec. 27.1301 Function and installation.
(a) Each item of installed equipment must -
(1) Be of a kind and design appropriate to its intended function;
(2) Be permanently and legibly marked or, if the item is too small to mark, tagged as to its identification, function, and operating limitations;
(3) Be installed according to limitations specified for that equipment; and
(4) Function properly when installed.
(b) No item of installed equipment may under any circumstance prevent the proper operation of any required system provided to the flight crew for controlling, navigating, or monitoring performance of the rotorcraft.

Explanation. See the proposal for Sec. 23.1391.
Ref. Proposal No. 862; Sec. 27.1301; Agenda Item A-1.

Sec. 27.1309 [Amended]
5-40. By changing the term in Sec. 27.1309(a) from "subchapter" to "chapter".
Explanation. See the proposal for Sec. 25.1309(a).
Ref. Proposal No. 789; Sec. 25.1309(a); Agenda Item A-2.

5-41. By adding a new Sec. 27.1311 to read as follows:

Sec. 27.1311 Automatic flight control system.
(a) Each automatic flight control system must be designed so that it can -
(1) Be quickly and positively disengaged by the pilots without moving their hands from the normal position on the cyclic control; and
(2) Be sufficiently overpowered by one pilot within the limits specified in Sec. 27.397 to let him control the rotorcraft.
(b) Unless there is automatic synchronization, each system must have a means to readily indicate to the pilot the alignment of the actuating device in relation to the control system it operates.
(c) Each manually operated control for the system's operation must be readily accessible to the pilots.
(d) The system must be designed and adjusted so that, within the range of adjustment available to the pilot, it cannot produce hazardous loads on the rotorcraft, or create hazardous deviations in the flight path, under any flight condition appropriate to its use, either during normal operation or in the event of a malfunction, assuming that corrective action begins within a reasonable period of time.
(e) Means independent of the mode selector switch must be provided to indicate to the flight crew the current mode of operation and the availability status of each alternate system.

Explanation. This proposal would provide standards applicable to automatic flight control systems in Part 27.
A proposal was made in Airworthiness Review Notice Number 2 (Notice 75-10) to add a new Sec. 27.1329 dealing with automatic pilot systems, and to amend Sec. 27.1329(a)(1) in a manner identical to that proposed for Sec. 27.1329(a)(1). These proposals were not included in the agenda for the first Airworthiness Review Conference. At the Conference, however, proposals concerning Sec. 23.1329 were discussed and have been included in this notice as proposals for Sec. 23.1311 (presently Sec. 23.1329). Pursuant to FAA's belief that the airworthiness standards should be consistent, to the extent practicable, throughout the aircraft certification parts (Part 23, 25, 27 and 29), new proposals for Secs. 27.1311 and 29.1311 are being made. The proposals contained in Notice Number 2 for Secs. 27.1329 and 29.1329 will be withdrawn at the time of final rulemaking action if the proposals for Secs. 27.1311 and 29.1311 are adopted, but all comments received in response to proposed Secs. 27.1329 and 29.1329 will be considered for Secs. 27.1311 and 29.1311.
The new proposals for Secs. 27.1311 and 29.1311 are similar to the previous proposals (in Notice Number 2) for Secs. 27.1329 and 29.1329(a)(1) except for the following: (1) Change in terminology from "automatic pilot system" to "automatic flight control system". (2) The change of the word "or" at the end of paragraph (a)(1) to "and". (3) the redesignation already noted. (4) The addition of paragraph (e). The change in terminology and the redesignation were proposed in Notice Number 2 for Sec. 25.1329. The change from the requirement that either paragraph (a)(1) or (a)(2) be complied with to a requirement that both be complied with is discussed in the proposal for Sec. 23.1329. For an explanation of paragraph (e) see the proposal for Sec. 25.1329(h).
A proposal is also being made for Parts 23,25 and 29.
Ref. Proposal Nos. 687, 795 ,868, 1315; Secs. 23.1329(a)(1), 25.1329(h), 25.1329, 27.1329; Agenda Items C-20, C-22.

Sec. 27.1321 [Amended]

5-42. By amending Sec. 27.1321 in a manner substantively identical to that proposed for Sec. 23.1321.

5-43. By amending Sec. 27.1323 by redesignating paragraph (b) as paragraph (c); by revising paragraph (a) and redesignating it as paragraph (b), and by adding a new paragraph (a) to read as follows:

Sec. 27.1323 Airspeed indicating system.
(a) Each airspeed indicating instrument must be calibrated to indicate true airspeed (at sea level with a standard atmosphere ) with minimum practicable instrument calibration error when the corresponding pitot and static pressures are applied.
(b) The airspeed indicating system must be calibrated in flight at forward speeds of 20 knots and over.
* * * * *

Explanation. The proposed addition of paragraph (a) would require that the airspeed instrument be calibrated according to the standard relationship between pressure and airspeed. A similar proposal is also made for Part 23, and is the same as the present Part 29 requirement.
Information available to the FAA indicates that the present 10 knot low speed calibration requirement (present paragraph (a) which is redesignated as paragraph (b)) is not achievable without extreme difficulty. The FAA believes that 20 knots would be a more realistic lowest-speed criterion.
Ref. Proposal Nos. 114, 129, 365; Secs. 23.1323(a), 27.1323(a); Agenda Items B-9, B-10.

5-44. By amending Sec. 27.1325 by revising the section heading; by designating the present paragraph as paragraph (a); and by adding a new paragraph (b), to read as follows:

Sec. 27.1325 Static pressure system.
* * * * *
(b) Each static pressure port must be designed and located in such manner that the correlation between air pressure in the static pressure system and true ambient atmospheric static pressure is not altered when the rotorcraft encounters icing conditions. An anti-icing means or an alternate source of static pressure may be used in showing compliance with this requirement.

Explanation. This proposal would provide the same level of safety, insofar as inadvertent icing of the static pressure port is concerned, as is currently provided for Part 23 airplanes. Part 27 rotorcraft now have increased performance, and operate over a wide range of environments, thereby increasing the exposure to icing.
Ref. Proposal No. 866; Sec. 27.1325(b); Agenda Item B-11.

Sec. 27.1327 [Amended]
5-45. By amending Sec. 27.1327(b) and (c) in a manner substantively identical to that proposed for Sec. 23.1327(b) and (c).

Sec. 27.1335 [New]
5-46 By adding a new Sec. 27.1335 that would be substantively identical to the proposed new Sec. 25.1335.

Sec. 27.1351 [Amended]
5-47. By adding a new Sec. 27.1351(e) that would be substantively identical to the proposed new Sec. 23.1351(f).

Sec. 27.1353 [Amended]
5-48. By amending Sec. 27.1353 in a manner substantively identical to that proposed for Sec. 23.1353.

Sec. 27.1357 [Amended]
5-49. By amending Sec. 27.1357(b) in a manner substantively identical to that proposed for Sec. 23.1357 (b).

5-50. By amending Sec. 27.1401 by striking "30" in both places in paragraph (b) and inserting in place thereof (in both places) the number "75"; and by revising Sec. 27.1401(d) and (f) to read as follows:

Sec. 27.1401 Anticollision light system.
* * * * *
(d) Color. Each anticollision light must be aviation red and must meet the applicable requirements of Sec. 27.1397.
* * * * *
(f) Minimum effective intensities for anticollision light. Each anticollision light effective intensity must equal or exceed the applicable values in the following table:

Angle above or below the horizontal plane:
Effective intensity (candles)
0 to 5
150
5 to 10
90
10 to 20
30
20 to 30
15
30 to 75
10

Explanation. See the proposal for Sec. 23.1401(b) and (f) for an explanation of Sec. 27.1401(b). A 10-candle minimum effective intensity in the 30 to 75 region is proposed for rotorcraft consistent with the general reduction of intensities proposed for Secs. 27.1401(f) and 29.1401(f). Service experience and experimentation by the military services has indicated that the intensities specified in present Sec. 27.1401 for rotorcraft anticollision lights are excessive because of objectionable multiple reflections in the cockpit, and that while anticollision lights are particularly objectionable (even at reduced intensity) in rotorcraft because of reflections and stroboscopic effects associated with having rotor blades in the flight crew's field of view. It is therefore proposed to reduce the present intensities to an acceptable level, and to limit the color to aviation red.
Ref. Proposal Nos. 368, 874, 408, 957, 873, 958, 407, 367; Secs. 27.1401(b), 29.1401(b), 27.1401(f), 29.1401(f); Agenda Items E-36, E-37.

5-51. By revising Sec. 27.1545(a) to read as follows:

Sec. 27.1545 Airspeed indicator.
(a) Each airspeed indicator must be marked as specified in paragraph (b) of this section, with the marks located at the corresponding indicated airspeeds.
* * * * *

Explanation. This proposal is made to clarify the marking requirement for airspeed indicators in Sec. 27.1545. See the proposal for Sec. 23.1545(a).
Ref. Proposal No. 129; Sec. 23.1545(a); Agenda Item B-9.

Sec. 27.1547 [Amended]
5-52. By adding a new Sec. 27.1547(e) that would be substantively identical to the proposed new Sec. 23.1547(e)

PART 29 - AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT

5-53. By revising Sec. 29.1301 to read as follows:

Sec. 29.1301 Function and installation.
(a) Each item of installed equipment must -
(1) Be of a kind and design appropriate to its intended function:
(2) By permanently and legibly marked or, if the item is too small to mark, tagged as to its identification, function, and operating limitations.
(3) Be installed according to limitations specified for that equipment; and
(4) Function properly when installed.
(b) No item of installed equipment may in any circumstance prevent the proper operation of any required system or of any other system provided to the flight crew for controlling, navigating, or monitoring performance of the rotorcraft.

Explanation. See the proposal for Sec. 23.1301.
Ref. Proposal No. 944; Sec. 29.1301; Agenda Item A-1.

5-54. By revising Sec. 29.1303(g) to read as follows:

Sec. 29.1303 Flight and navigation instruments.
The following are required flight and navigational instruments:
* * * * *
(g) A gyroscopic rate-of-turn indicator combined with an integral slip-skid indicator (turn-and-bank indicator) except that only a slip-skid indicator is required on rotorcraft with a third attitude instrument system that -
(1) Is useable through flight attitudes of 80 of pitch and 120 of roll;
(2) Is powered from a source independent of the electrical generating system;
(3) Continues reliable operation for a minimum of 30 minutes after total failure of the electrical generating system;
(4) Operates independently of any other attitude indicating system;
(5) Is operative without selection after total failure of the electrical generating system;
(6) Is located on the instrument panel in a position acceptable to the Administrator that will make it plainly visible to and useable by any pilot at his station; and
(7) Is appropriately lighted during all phases of operation.
* * * * *

Explanation. Present Part 25 does not require a gyroscopic rate-of-turn indicator when the airplane is fitted with a third attitude instrument system meeting certain conditions. The same exception is equally applicable to transport category rotorcraft.
Ref. Proposal No. 946; Sec. 29.1303(g); Agenda Item B-16.

5-55. By amending Sec. 29.1309 by changing the term in Sec. 29.1309(a) and (d) from "subchapter" to "chapter"; by deleting the word "four" in Sec. 29.1309(e) and inserting the word "three" in place thereof; and by revising Secs. 29.1309(d)(3)(i) and (ii) to read as follows:

Sec. 29.1309 Equipment, systems, and installations.
* * * * *
(d) * * *
(3) * * *
(i) Any one engine, on rotorcraft with two engines; and
(ii) Any two engines, on rotorcraft with three or more engines.
* * * * *

Explanation. See the proposal for Sec. 25.1309.
Ref. Proposal No. 299, 789; Sec. 25.1309(e), 25.1309(a); Agenda Items A-2, A-6.

Sec. 29.1321 [Amended]
5-56. By amending Sec. 29.1321 in a manner substantively identical to that proposed for Sec. 23.1321.

5-57. By amending Sec. 29.1325 by revising the section heading; by redesignating paragraphs (e), (d), and (e) as paragraphs (d), (e), and (f) respectively; and by adding a new paragraph (c), to read as follows:

Sec. 29.1325 Static pressure and pressure altimeter systems.
* * * * *
(c) Each static pressure port must be designed and located in such manner that the correlation between air pressure in the static pressure system and true ambient atmospheric static pressure is not changed when the rotorcraft is exposed to the continuous and intermittent maximum icing conditions defined in Appendix C of Part 25.
* * * * *

Explanation. This proposal would provide the same level of safety, insofar as inadvertent icing of the static pressure port is concerned, as is provided for Part 25 airplanes. Part 29 rotorcraft now have increased performance, and operate over a wider range of environments, thereby increasing the exposure to icing.
Ref. Proposal No. 952; Sec. 29.1325; Agenda Item B-11.

5-58. By redesignating Sec. 29.1329 as Sec. 29.1311; and by revising the heading and paragraph (a), and by adding a new paragraph (e), to read as follows:

Sec. 29.1311 Automatic flight control systems.

(a) Each automatic flight control system must be designed so that it can -
(1) Be quickly and positively disengaged by the pilots without moving their hands from the normal position on the cyclic control; and
(2) Be sufficiently overpowered by one pilot within the limits specified in Sec. 29.397 to let him control the rotorcraft.
* * * * *
(e) Means independent of the mode selector switch must be provided to indicate to the flight crew the current mode of operation and the availability status of each alternate system.

Explanation. See the proposal for Sec. 27.1311.
Ref. Proposal Nos. 687, 795, 868, 1315; Secs. 23.1329(a)(1), 25.1329(h), 25.1329, 27.1329; Agenda Items C-20, C-22.

Sec. 29.1335 [New]
5-59. By adding a new Sec. 29.1335 that would be substantively identical to the proposed new Sec. 25.1335.

5-60. By adding a new Sec. 29.1351(d) that would be substantively identical to the proposed new Sec. 23.1351(f); and by adding a new Sec. 29.1351(c) to read as follows:

Sec. 29.1351 General.
* * * * *
(c) Operation without normal electrical power. It must be shown by analysis, tests, or both, that the rotorcraft can be operated safely in VFR conditions, for a period of not less than five minutes, with the normal electrical power inoperative with critical type fuel (from the standpoint of flameout and restart capability), and with the rotorcraft initially at the maximum certificated altitude. Parts of the electrical system may remain on if -
(1) A single malfunction, including a wire bundle or junction box fire, cannot result in loss of the part turned on and the part turned off;
(2) The parts turned on are electrically and mechanically isolated from the parts turned off; and
(3) The electrical wire and cable insulation, and other materials, of the parts turned on are self-extinguishing when tested in accordance with Sec. 25.1359(d) in effect on (date on which this proposal would become effective).

Explanation. The substance of the proposed paragraph (c) has been applied as a special condition to Part 25 airplanes for the past few years. It is equally applicable to Part 29 rotorcraft. See the proposal for Sec. 25.1351.
Ref. Proposal No. 954; Sec. 29.1352; Agenda Item D-24.

Sec. 29.1353 [Amended]
5-61. By amending Sec. 29.1353 in a manner substantively identical to that proposed for Sec. 23.1353.

5-62. By revising Sec. 29.1355(b)(1) to read as follows:

Sec. 29.1355 Distribution system.
* * * * *
(b) Each system must be designed so that -
(1) For category A rotorcraft, essential load circuits can be supplied in the event of reasonably probable faults or open circuits; and
* * * * *

Explanation. The reference to "individual distribution systems" in the present rule is superfluous. The lead-in specifies "each system", and Sec. 29.1355(a) defines the components of each distribution system. It is proposed to clarify the present requirement by deleting the words "individual distribution systems ensure that".
Ref. Proposal No. 405; Sec. 29.1355; Agenda Item D-28.

Sec. 29.1401 [Amended]
5-63. By amending Sec. 29.1401 in a manner substantively identical to that proposed for Sec. 27.1401.

Sec. 29.1457 [Amended]
5-64. By amending Sec. 29.1457(b), (d)(1), and (e) in a manner substantively identical to that proposed for Sec. 25.1457(b), (d)(1), and (e).

Sec. 29.1545 [Amended]
5-65. By amending Sec. 29.1545(a) in a manner substantively identical to that proposed for Sec. 23.1545(a).

PART 91 - GENERAL OPERATING AND FLIGHT RULES

5-66. By revising Sec. 91.33(d)(3) to read as follows:

Sec. 91.33 Powered civil aircraft with standard category U.S. airworthiness certificates; instrument and equipment requirements.
* * * * *
(d) Instrument flight rules. For IFR flight the following instruments and equipment are required:
* * * * *
(3) Gyroscopic rate-of turn indicator, except on the following aircraft:
(i) Large airplanes with a third attitude instrument system useable through flight attitudes of 360 of pitch and roll and installed in accordance with Sec. 121.305(j) of this chapter; and
(ii) Rotorcraft, type certificated under Part 29 of this chapter, with a third attitude instrument useable through flight attitudes of 80 of pitch and 120 of roll and installed in accordance with Sec. 29.1303(g) of this chapter.
* * * * *

Explanation. In view of the proposed revision of Sec. 29.1303(g), which would allow, under certain conditions, the substitution of a third attitude gyro for the required gyroscopic rate-of-turn indicator, it is proposed to adjust Sec. 91.33(d)(3).
Ref. Proposal No. 946; Sec. 29.1303(g); Agenda Item B-16.

5-67. By amending Sec. 91.36 by striking the word "or" at the end of paragraph (a); by striking the period at the end of paragraph (b) and inserting in place thereof a semicolon followed by the word "or"; and by adding a new paragraph (c) to read as follows:

Sec. 91.36 Data correspondence between automatically reported pressure altitude data and the pilot's altitude reference.
* * * * *
(c) After (a date one year after the effective date of this amendment), unless the altimeters and digitizers in that equipment meet the performance standards in TSO-C10b and TSO-C88, respectively.

Explanation. This proposal, by specifying that altimeters and digitizers (those associated with automatic pressure altitude reporting equipment) meet existing Technical Standard Order performance standards, would prevent the introduction of equipment with unacceptable performance on operational aircraft. Substandard equipment could seriously degrade the Air Traffic Control System's altitude reporting capability.
Ref. Proposal No. 1012; Sec. 91.36; Agenda Item B-19.

PART 121 - CERTIFICATION AND OPERATION: DOMESTIC, FLAG, AND SUPPLEMENTAL AIR CARRIERS AND COMMERCIAL OPERATORS OF LARGE AIRCRAFT

5-68. By amending Sec. 121.337 by striking the last sentence of paragraph (a) including the parenthetical and inserting in place thereof two sentences to read as follows:

Sec. 121.337 Protective breathing equipment for the flight crew.

(a) * * * There must be at least a 300-liter, normal temperature and pressure (70F and 760mm.HG respectively) dry, supply of oxygen for each required flight crewmember on flight deck duty. After (date one year after the effective date of this amendment) the equipment provided must be fitted to each flight crewmember to provide the protection specified in this paragraph.
* * * * *

Explanation. The proposal would require, after one year after the effective date of this amendment, that protective breathing equipment be fitted to each crewmember for whom it must be provided under Sec. 121.337(a), to ensure that the equipment affords the specified protection. Without such fitting, entry of harmful gases can occur, as experience has shown.
It is also proposed to specify the presently required supply of oxygen at normal rate than standard temperature and pressure, to be consistent with the requirement in present Sec. 25.1439(b)(5).
Ref. Proposal No. 1093, 532; Sec. 121.337(a); Agenda Item H-51.

5-69. By revising Sec. 121.343(a) to read as follows:

Sec. 121.343 Flight recorders.
(a) No person may operate a large airplane that is certificated for operations above 25,000 feet altitude or is turbine engine powered, unless it is equipped with one or more approved flight recorders that record data from which the following information may be determined and, if set forth in Appendix B of this part, within the ranges, accuracies, and recording intervals specified in Appendix B of this part:
(1) Time, altitude, airspeed, vertical acceleration, heading, and the information specified in paragraphs (a)(2) and (a)(3) of this section, as applicable.
(2) Except as provided in paragraph (a)(3) of this section, for airplanes having an original type certificate issued after September 30, 1969, pitch attitude, roll attitude, side slip angle or lateral acceleration, pitch trim position, control column or pitch control surface position, control wheel or lateral control surface position, rudder pedal or yaw control surface position, thrust of each engine, position of each trust reverser, trailing edge flap or cockpit flap control position, and leading edge flap or cockpit flap control position.
(3) After (date one year after the effective date of this proposed amendment), for airplanes having an original airworthiness certificate issued on or after (date one year after the effective date of this proposed amendment) and for airplanes having an original type certificate issued after September 30, 1969, (regardless of the date of the original airworthiness certificate), pitch attitude, roll attitude, side slip angle or lateral acceleration, pitch trim position, control column and pitch control surface position, control wheel and lateral control surface position, rudder pedal and yaw control surface position, thrust of each engine position of each thrust reverser, trailing edge flap or cockpit flap control position, Greenwich mean time, automatic flight control system selected mode and engagement status, spoiler and speedbrake position, selected flight director mode, localizer and glide-slope deviation, hydraulic system status, electrical bus status, activation of each fire warning system, activation of the pressurization system cockpit warning, vertical acceleration recorded at 0.25 second intervals, longitudinal acceleration, outside ambient or total air temperature, position of the strut extension-retraction switch, indication of outer, middle, and inner marker passage, and radio altitude.
* * * * *

Explanation. The present flight recorder requirements are restated in paragraph (a)(1) and (a)(2) except for minor revisions to account for the new requirement in paragraph (a)(3). Proposed paragraph (a)(3) would add several new parameters. Also, some changes would be made to items now set forth in paragraph (a)(2). The new parameters begin with "Greenwich mean time" and go to the end of the sentence in the proposed paragraph (a)(3). The changes to items now set forth include replacing the "or"s after "control column", "control wheel", and "rudder pedal" with "and"s.
Flight recorders capable of recording the additional parameters would be required (after a date one year after the effective date of the proposed amendment) on airplanes having an original airworthiness certificate issued after that date and on airplanes having an original type certificate issued after September 30, 1969, regardless of the date of the original airworthiness certificate. Proposed paragraph (a)(1) and (a)(2) would allow airplanes to operate under present flight recorder rules until the new parameters are required.
The National Transportation Safety Board has found that, because of factors such as the increased sophistication of airplane design, ground-based navigation equipment and approach guidance equipment, the currently-prescribed information is sometimes inadequate for the determination of the cause of airplane accidents. Although there may be a need to specify ranges, accuracies, and recording intervals, for certain of the additional parameters, none are proposed at this time. However, the FAA plans to undertake separate rulemaking to incorporate such standards under the Technical Standard Order systems.
Ref. Proposal No. 535; Sec, 121.343; Agenda Item I-52.

5-70. By revising Sec. 121.359(c) to read as follows:

Sec. 121.359 Cockpit voice recorder.
* * * * *
(c) The cockpit voice recorder required by this section must meet the following application standards:
(1) Except as provided in paragraphs (c)(3) and (c)(4) of this section, the requirements of Part 25 of this chapter in effect on (date one day before the effective date of this amendment).
(2) After (date one year after the effective date of this amendment), each recorder container must -
(i) Be either bright orange or bright yellow;
(ii) Have reflective tape affixed to the external surface to facilitate its location under water; and
(iii) Have an approved underwater locating device on or adjacent to the container which is secured in such a manner that they are not likely to be separated during crash impact.
(3) After (date two years after the effective date of this amendment), each cockpit voice recorder installation must comply with Sec. 25.1457(b) and (d) in effect on (the effective date of this amendment).
(4) After (date five years after the effective date of this amendment) each cockpit voice recorder installation must comply with Sec. 25.1457(e) in effect on (the effective date of this amendment).
* * * * *

Explanation. Present Sec. 121.359(c) requires that voice recorders be installed in accordance with the requirements of Part 25 of this chapter. It is also proposed to require that each cockpit voice recorder container have reflective tape affixed, and an underwater locating device, one year after the effective date of the amendment. The requirement that the record container be either bright orange or bright yellow is in the present rule and is restated in the proposed rule to have all the container requirements together.
Experience has shown that underwater locating devices greatly facilitate underwater recovery of the record containers which contain important accident investigation data. Reflective tape enables pinpoint location of the record container after its general location by the underwater locating device. The amendment would not become applicable for Part 121 operators until one year after the effective date of this proposed amendment to allow time for procurement and installation.
For an explanation of Sec. 121.359(c)(3) and (c)(4), see the proposals for Sec. 25.1457. This proposal would require cockpit voice recorder installations on airplanes operated under Part 121 to meet proposed Sec. 25.1457(b) and (d)(1) within two years, and proposed Sec. 25.1457(e) within five years.
Ref. Proposal Nos. 325, 324, 537 ,817; Secs. 25.1457, 121.359; Agenda Items I-55, I-54, I-56.

PART 127 - CERTIFICATION AND OPERATIONS OF SCHEDULED AIR CARRIERS WITH HELICOPTERS

5-71. By revising Sec. 127.127(b) to read as follows:

Sec. 127.127 Cockpit voice recorders.
* * * * *
(b) Except as provided in paragraphs (b)(1) and (b)(2) of this section, each cockpit voice recorder must be installed in accordance with the requirements of Part 29 of this chapter in effect on (date one day before the effective date of this amendment).
(1) After (date two years after the effective date of this amendment) each cockpit voice recorder installation must comply with Sec. 29.1456(b) and (d)(1) in effect on (the effective date of this amendment).
(2) After (date five years after the effective date of this amendment) each cockpit voice recorder installation must comply with Sec. 29.1457(e) in effect on (the effective date of this amendment).
* * * * *

Explanation. See the proposals for Sec. 25.1457(b), (d)(1), and (e) and Sec. 29.1457(b), (d)(1), and (e). This proposal would require that cockpit voice recorders on rotorcraft operated under Part 127 be modified to meet proposed Sec. 29.1457(b) and (d)(1) within two years after the effective date of this amendment, and proposed Sec. 29.1457(e) within five years after the effective date of this amendment.
Ref. Proposal Nos. 324, 537, 817; Secs. 25.1457, 121.359; Agenda Items I-54, I-56.

Appendix I Committee V (Systems) Proposals Deferred

Based upon the discussions at the Airworthiness Review Conference, the FAA has determined that the proposals listed below appear to have sufficient merit to warrant further consideration but for various reasons should be deferred for consideration at the next Airworthiness Review or Operations Review as appropriate. Included in the reasons for deferral are the following:
1. The proposal is so complex or extensive that more time is required than is available within the 1974-75 Airworthiness Review to give it full consideration.
2. There is insufficient data presently available on which to base a decision on the outcome of the proposal.
3. The proposal would be more appropriately considered during an operations review.
The deferral of these proposals does not foreclose the FAA from taking separate rulemaking action on the deferred proposals if a need for such action should arise.

14 CFR (FAR section)
Proposal No.
Agenda Item
Proponent
25.831
250
G-42
Joint Airworthiness Requirements Committee.
25.1431
316
J-59
Air Line Pilots Association.
43.15
466
B-17
Sun Chemical Corp.
Pt. 91
484
J-60
Curtis Hewitt.
91.33
494
J-61
General Motors Corp.
91.161
502
B-17
Sun Chemical Corp.
91.170
507
B-17
Do.
121.349
536
J-65
Aerospace Industries Association.
135.153
552
J-66
Air Line Pilots Association.

Appendix II Committee V (Systems) Proposals Withdrawn by Proponent.

The proposals listed below were withdrawn by their proponents after the publication of the committee workbooks but prior to the end of the Airworthiness Review Conference. The proponents or other interested persons may submit similar proposals in the future. The withdrawal of FAA proposals does not commit the FAA to any future course of action.

14 CFR (FAR section)
Proposal No.
Agenda Item
Proponent
23.1323
683
B-9
Federal Aviation Administration.
23.1435
700
F-41
Do.
25.1309
790
A-5
Do.
25.1351
304
D-24
Aerospace Industries Association.
25.1435
320
F-41
Do.
25.1443
814
H-46
Federal Aviation Administration.
25.1547
823
B-13
Do.
135.159
1104
J-66
Do.
135.155
1106
J-66
Air Line Pilots Association.

Appendix III Committee V (Systems) Proposals Removed from Consideration

Based on the FAA's review of the discussion at the Airworthiness Review Conference and of the information submitted by interested persons, the following proposals considered by Committee V at the Airworthiness Review Conference are removed from consideration during the First Biennial Airworthiness Review for the reasons listed below:

14 CFR (FAR section)
Proposal No.
Agenda Item
Proponent
Pt. 23
57
A-4
National Transportation Safety Board.
23.1357
120
D-33
Department of Transportation - Australia.
23.1401
122
E-38
General Aviation Manufacturers Association.
23.1401
123
E-35
Air Line Pilots Association.
25.831
252
G-43
General Aviation Manufacturers Association.
25.841
253
G-44
Aerospace Industries Association.
25.1309
140
A-4
National Transportation Safety Board.
25.1329
301
C-21
Aerospace Industries Association.
25.1351
167
D-25
Do.
25.1351
305
D-27
Do.
25.1351
306
D-26
Do.
25.1401
312
E-35
Air Line Pilots Association.
25.1435
318
F-40
Aerospace Industries Association.
25.1447
323
H-48
Do.
27.1401
366
E-35
Air Line Pilots Association.
29.1401
406
E-35
Do.
91.33
488
B-18
Department of Transportation - Australia.
91.33
492
E-35
Air Line Pilots Association.
91.52
499
J-62
General Motors Corp.
121.318
527
J-63
Aerospace Industries Association.
121.319
528
J-64
Do.

Proposal No. 57 - The proponent requested that Parts 23 and 25 be amended to require that safety analyses be completed in a manner similar to that required by "Military Standard 882, System Safety Program for Systems and Associated Subsystems and Equipment: Requirements for." The FAA believes that adoption of the proposed rule is inappropriate because -
1. Other adequate methods of safety assessment and fault analysis exist;
2. The proposed requirement would severely limit and would tend to dictate design procedures; and
3. The experience to date with Sec. 25.1309 does not justify the regulation change.

Proposal No. 120 - The proponent, citing instances of non-compliance with Sec. 23.1357(c), requested that the rule be clarified. The FAA believes that the current rule is sufficiently definitive. The FAA has initiated an investigation to determine if alleged noncompliance exists, and if it does, appropriate action will be taken.

Proposal No. 122 - The proposal would "establish a means by which parts or components produced to a higher standard can be installed without the need to recertificate the whole aircraft". The FAA believes that the regulations now provide appropriate methods for the approval of aircraft parts or components produced to an equivalent or higher standard. The procedures for such approval must include an adequate balance of all interests, and the FAA does not believe that this procedure should be amended without further justification. A procedure for each type of system set forth in the regulations as proposed, would yield an unmanageable regulatory system.

Proposal No. 123 - This proposal would require that xenon strobe lights be installed at specific locations on each aircraft. Xenon lights are already permitted by regulation. To require that only this type be used would be too restrictive since other types of satisfactory lights exist.

Proposal No. 252 - The proponent suggested that Sec. 25.831 be amended to provide for relaxed ventilation control requirement for small airplanes. The purpose of the proposal is covered by the proposed amendment to Sec. 25.831, 46 FR 10810 (Notice 75-10).

Proposal No. 253 - The proposal would allow the use of a 10,000-foot cabin pressure altitude for all-cargo airplanes. The FAA believes that exposure of the crew to a cabin pressure altitude of 10,000 feet (as opposed to the currently prescribed 8,000 feet) would lead to a significant degradation of crew performance and efficiency.

Proposal No. 140 - See the comments for Proposal No. 57.

Proposal No. 301 - This proposal would increase the airplane velocity limit for autopilot malfunction to that specified in Sec. 25.253(a)(2). Those speeds, however, assume manual flying within control force limits without a failed autopilot. The FAA believes that the human pilot, working against adverse control forces being applied by a malfunctioning autopilot, needs an increment of safety achievable by specifying, during type certification, a finite limit on the authority of the autopilot. That limit should be the lowest practicable and the FAA believes that the value set forth (as an acceptable means of compliance) in AC 25.1329-1A is satisfactory for this purpose.

Proposal No. 167 - The proposal would have amended Sec. 25.1351(b) to allow a momentary loss of power to essential circuits due to switching, fault clearing, or other causes. The FAA has determined that insufficient justification was presented to justify the possible degradation in safety which could result from adoption of the proposal.

Proposal No. 305 - The proposal would amend Sec. 25.1351(b) to provide for power sources which cannot be disconnected. The FAA has determined that utilization of power source without a disconnect capability is an inappropriate change at the present time and that insufficient justification has been provided to warrant the possible degradation in flight safety.

Proposal No. 306 - This proposal would eliminate the reference to voltage and current in Sec. 25.1351(b)(6). Those references are examples and not requirements. The present rule provides adequate flexibility.

Proposal No. 312 - See the comments for Proposal No. 123.

Proposal No. 318 - This proposal would allow an alternative design criterion from hydraulic fluid quantity indicators by allowing a low quantity warning light to satisfy the present requirement. With respect to Sec. 25.1435(a)(3), the FAA believes that warning lights alone do not provide an adequate indication of the quantity of fluid in each continually operating system.

Proposal No. 323 - The proponent requested the elimination of the present requirement that portable oxygen equipment be immediately available to flight attendants. The FAA has determined that adoption of the proposal would result in an unjustified degradation in the level of safety currently provided by regulation.

Proposal No. 366 - See the comments for Proposal No. 123.

Proposal No. 406 - See the comments for Proposal No. 123.

Proposal No. 488 - The proponent assumed that requiring "approved" altimeters as proposed would assure that all altimeters meet the altimeter TSO. This is not the case since under Sec. 21.305 there are other methods by which an altimeter may be approved. Those methods have proven adequate in the past and a change that would eliminate them has not been justified.

Proposal 492 - See comments for Proposal No. 123.

Proposal No. 499 - This proposal would permit certain aircraft operation with an inoperative ELT. Such a change is inconsistent with the Public Law and beyond the scope of the Airworthiness Review Program.

Proposal No. 527 - This proposal covers provisions included in Notice 75-14 [40 FR 11736], March 12, 1975.

Proposal No. 528 - This proposal covers provisions included in Notice 75-14 [40 FR 11736], March 12, 1975.



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Issued in Washington, DC, on May 19, 1975.
J. A. Ferrarese,
Acting Director, Flight Standards Service.
[FR Doc. 75-13607 Filed 5-23-75; 8:45 am]


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Other Notice of Proposed Rulemaking Actions:

Notice of Invitation to Submit Proposals; Notice No. 74-5; Issued on 2/14/74.
Notice of Compilation of Proposals; Notice No. 74-5A; Issued on 5/22/74.
Notice of Availability of Agenda; Notice No. 74-5B; Issued on 10/3/74.
Notice of Clarifying Revisions; Notice No. 74-33; Issued on 10/3/74.
Notice of Conference; Notice No. 74-5C; Issued on 11/25/74.
Notice of Availability of Conference Summary; Notice No. 74-5D; Issued on 2/4/75.
Notice of Airworthiness Review Program No. 2; Notice No. 75-10; Issued on 2/27/75.
Notice of Airworthiness Review Program No. 3; Notice No. 75-19; Issued on 5/13/75.
Notice of Airworthiness Review Program No. 4; Notice No. 75-20; Issued on 5/13/75.
Notice of Airworthiness Review Program No. 6; Notice No. 75-25; Issued on 5/29/75.
Notice of Airworthiness Review Program No. 7; Notice No. 75-26; Issued on 6/9/75.
Notice of Airworthiness Review Program No. 8; Notice No. 75-31; Issued on 6/30/75.

Final Rule Actions:

Final Rule. Docket No. 14625; Issued on 02/03/76.
Final Rule. Docket No. 14324; Issued on 12/13/76.
Final Rule. Docket No. 14625; Issued on 07/11/77.
Final Rule. Docket No. 14324, 14606, 14625, 14685, 14779; Issued on 10/20/78.