Flight Controls, Trailing Edge (TE) Flap Control System

1 FAA Aviation Safety SPECIAL AIRWORTHINESS INFORMATION BULLETIN SUBJ: Flight Controls, Trailing Edge (TE) Flap Control System SAIB: CE-16-27 Date: October 31, 2016 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) is being issued to alert owners, operators, maintenance technicians, and inspectors of an airworthiness concern for Air Tractor, Inc. (Air Tractor) Models AT-802/802A/602/504/503/503A/502/502A/502B/501/402/402A/402B /401/ 401A/ /401B/400/400A/302/301/300/250 airplanes (under Type Certificate Data Sheets A9SW, A17SW, and A19SW). Specifically, this SAIB provides inspection procedures and on-condition maintenance actions for the flap torque tube for affected airplanes.

At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

Air Tractor, Inc. recently issued Snow Engineering Co. Service Letter (SL) #347 for all the above- referenced models of Air Tractor airplanes. The SL was issued after in-flight failure of the flap torque tube on a Model AT-802A airplane. Failure of the welds attaching the flap actuator brackets to the torque tube resulted in uncommanded retraction of both flaps. One other crack in a flap torque tube bracket weld was reported for a Model AT-502B airplane in 2007. The SL provides owners and operators instructions for inspection of the torque tube attach brackets for cracks in the welds and replacement of the torque tube if cracks are found. SL #347 also requests that you report any cracks you find to the Air Tractor Customer Service Department using the contact information provided.

Recommendations

The FAA recommends inspection of the flap torque tube using the procedures in SL #347 and a report of any cracks found to the Air Tractor Service Department.

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120- 0731. Public reporting for this collection of information is estimated to be approximately 5 minutes per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, completing and reviewing the collection of information. All responses to this collection of information are voluntary. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to the FAA at: 800 Independence Ave. SW, Washington, DC 20591, Attn: Information Collection Clearance Officer, ASP-110.

2 For Further Information Contact

Andrew McAnaul, Aerospace Engineer, ASW-143, c/o SAT-MIDO-43, 10100 Reunion Place Suite 650, San Antonio, TX 78216; phone: (210) 308-3365, fax: (210) 308-3370; e-mail: [email protected]

Kristi Bradley, Aerospace Engineer, ASW-143, Aircraft Certification Office, 10101 Hillwood Pkwy, Fort Worth, TX 76177; phone: (817) 222-5485; email: [email protected]

For Related Service Information or to Report Inspection Findings Contact

Air Tractor, Inc., P.O. Box 485, Olney, Texas, 76374; phone: (940) 564-5616; fax: (940) 564-5612; email: [email protected].