FAA SPECIAL AIRWORTHINESS
Aviation Safety INFORMATION BULLETIN
SAIB: CE-18-06
SUBJ: Flight Controls, Rudder Control System Date: December 1, 2017
This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) informs registered owners/operators of an
airworthiness concern for Air Tractor, Inc. Models AT-401B, AT-402B, AT-502A, AT-502B,
AT-504, AT-602, AT-802, and AT-802A having serial numbers prior to 401B/402B-1347,
502A/502B-3059, 504-4029, 602-1278, and 802/802A-0661 airplanes (under Type Certificate Data
Sheets A17SW and A19SW) of an airworthiness concern. Specifically, this SAIB specifies and
recommends the use of procedures for replacement of the bolts and nuts through the vertical fin rear
spar.
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. issued Snow Engineering Co. Service Letter (SL) #359, Revision A, dated
November 29, 2017, for the Air Tractor airplanes referenced in the Introduction section of this SAIB.
The SL was issued after an in-flight failure of the bolts at the vertical fin rear spar attach connection,
which caused the rudder boost trim mounting bracket to migrate out of its normal position. To date,
there have been two failures of these bolts. Failure of these bolts may lead to difficulty controlling the
airplane. The SL specifies instructions for replacement of the nuts and bolts through the vertical fin
rear spar attach point.
Recommendations
The FAA recommends that the affected owners of the Air Tractor airplanes referenced in the
Introduction section of this SAIB replace the six bolts and nuts through the vertical fin rear spar with
NAS1303 bolts and MS21042-3 nuts at the next annual inspection using the procedures in SL #359,
Revision A, dated November 29, 2017. Before the next flight, the FAA also recommends that
affected owners remove the surrounding skin to visually inspect both the forward and aft sides of the
bolts for damage. The FAA recommends that you report any findings of damaged bolts to the FAA
points of contact listed below. Providing this information is strictly voluntary as indicated below:
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. Under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the OMB has
approved the information collection contained in this SAIB, and assigned OMB Control
Number 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
1
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.
For Further Information Contact
Kristi Bradley, Aerospace Engineer, AIR-7F2, Fort Worth ACO Branch, 10101 Hillwood Pkwy, Fort
Worth, TX 76177; phone: (817) 222-5485; email:
[email protected]
Kenneth Cook, Aerospace Engineer, AIR-7F1, Fort Worth ACO Branch, 10101 Hillwood Pkwy, Fort
Worth, TX 76177; phone: (817) 222-5475; e-mail:
[email protected]
For Related Service Information Contact
Air Tractor, Inc., P.O. Box 485, Olney, Texas, 76374; phone: (940) 564-5616; fax: (940) 564-5612;
email:
[email protected].
2
Please find attached a Foreign State of Design Advisory document, endorsed by EASA.
This advisory document is also online at https://ad.easa.europa.eu/ad/CE-18-06 .
Should you have any questions, please contact the Agency by e-mail at
[email protected] or by fax,
No.: +49 221 89990 9515.
Safety Information Section Email:
[email protected]
EASA Website
(Attachment is in Acrobat PDF format)
Postal: Postfach 10 12 53, 50452 Cologne, Germany
An agency of the European Union
This message is intended for the use of the addressee only and may contain information that is privileged and confidential. If you are not the
intended recipient, you are notified that any dissemination of this communication is strictly prohibited. If you have received this
communication in error, please notify us immediately by returning this e-mail. Sender accepts no liability for damage of any kind resulting from
the risks inherent in the electronic transmission of messages. This communication does not constitute any formal commitment on behalf of the
European Aviation Safety Agency.