Federal Aviation Administration

Special Airworthiness Information Bulletin

- CE-04-23.pdf

SPECIAL AIRWORTHINESS INFORMATION BULLETIN Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration CE-04-23 December 2, 2003

www.faa.gov - Search "SAIBs"
This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin informs you, registered owners and operators of Air Tractor Inc. aircraft listed below, of the potential for failure of the eyebolt that attaches the horizontal stabilizer spar to the stabilizer strut.

AT-300	AT-301	AT-302
AT-400	AT-400A	AT-401 and AT-402 through S/N 0700
AT-602	AT-802	AT-802A

Background

We have received reports of failed eyebolts on Air Tractor AT-300, AT-400 and AT-600 series models. Air Tractor issued Snow Engineering Service Letter (SL) #62 in 1985 in response to reports of cracked eyebolts in AT-300 series aircraft. In 1994, they issued SL #129 to replace eyebolts at 2000-hour intervals in response to another reported eyebolt failure. Air Tractor has now issued revised SL #129, dated 11/5/03, to replace the eyebolts every 1350 hours Time-in-Service (TIS) in response to a recent eyebolt failure reported on an AT-602 aircraft.

Starting with serial number 401-0701, Air Tractor incorporated larger size eyebolts into production aircraft. We are not aware of any failures of the larger eyebolts on AT-300/400/500 series aircraft. We have received one report of a failure of the larger eyebolt on an AT-602 aircraft, which like the AT-802 and AT-802A, has larger horizontal tail surfaces than the AT-300/400/500 series.

Recommendation

The FAA strongly recommends that starting at 1350 hours TIS, you replace the eyebolts in accordance with SL #129, revised 11/5/03. You should replace the eyebolts at intervals of every 1350 hours TIS thereafter. These actions will help insure the continued airworthiness of your airplane. Refer to Service Letter #129 for aircraft model and serial number effectivity, and applicable replacement eyebolt part numbers. To maintain a service history, we request you report eyebolts found cracked or failed to the manufacturer.

For Further Information Contact

Andrew McAnaul, Aerospace Engineer, DOT/FAA, SAT SW-MIDO-43, 10100 Reunion Place, Suite 650, San Antonio, TX 78216; phone: (210) 308-3365; fax: (210) 308-3370; e-mail: andrew.mcanaul@faa.gov

You can obtain copies of Service Letter #129 from the Air Tractor Customer Service Department at (940) 564-5616, or through your local Air Tractor Dealer.