Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
2023-14
November 14, 2023
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin is to alert owners,
operators, and maintenance personnel of a potential fractured clevis
mounting boss on the main landing gear strut on Twin Commander Aircraft
LLC Model 500A, 500B, 500S, 500U, 560-F, 680F, 680F(P), 680FL,
680FL(P), 680T, 680V, 680W, 681, 685, 690, 690A, 690B, 690C, 690D, 695,
695A, and 695B 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
On March 2, 2022, a Twin Commander 500S was involved in an incident in
which the right main landing gear failed to fully extend and lock in
the down position prior to landing. It was observed that the right main
landing gear separated from the actuating cylinder due to a fractured
clevis mounting boss on the main landing gear strut. It was determined
that the fractured clevis mounting boss prevented the right main
landing gear from lowering to the down and locked position.
Recommendations
The FAA recommends owners, operators, and maintenance personnel of the
affected aircraft inspect each main landing gear assembly and report
inspection results to the manufacturer, in accordance with Twin
Commander Service Letter 376, Inspection of Main Landing Gear Clevis
and Drag Brace Installations, dated April 25, 2000.
Paperwork Reduction Act Burden Statement
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 currently 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 1 hour 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; the nature and extent of confidentiality to be provided, if
any. Send comments regarding this burden estimate or any other aspect
of this collection of information, including suggestions for reducing
this burden to: Information Collection Clearance Officer, Federal
Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX
76177-1524.
For Further Information Contact
Vu Tran, Aviation Safety Engineer, 1701 Columbia Avenue, College Park,
GA 30337; phone: (404) 474-5592; e-mail: vu.h.tran@faa.gov.
For Related Service Information Contact