SPECIAL AIRWORTHINESS INFORMATION BULLETIN
Aircraft Certification Service
Washington, DC
U.S. Department of Transportation
Federal Aviation Administration
2022-24

December 23, 2022

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 Seamax Aircraft LTDA (Seamax) Model M-22 light-sport airplanes which incorporate the folding wing optional assembly. Specifically, this SAIB provides procedures to inspect the wing strut attachment hardware for proper security. 
 
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. However, the Seamax M-22 is a Light –Sport category aircraft and if Seamax Aircraft LTDA issues a Safety Directive for this issue, compliance will be mandatory per the operational limitations that are provided with the airworthiness certificate. 
 
Background
 
On October 6, 2022, a Seamax M-22 light-sport airplane, registration number N46PD, was destroyed in an accident near East Hampton, New York. The private pilot was fatally injured. The airplane was operated under 14 Code of Federal Regulations Part 91 as a personal flight. 
 
As documented in NTSB preliminary report ERA23FA007, the right wing was separated from the main wreckage and located in a tree, and the right wing strut was separated from the right wing. The bolt attaching the right strut to the right wing remained attached to the right wing and was not fractured; however, the nut was not present. In addition, the bolt threads did not exhibit significant damage. The NTSB’s investigation of this event is ongoing and a probable cause has not been determined. 
 
Seamax has previously issued two Service Bulletins which provide instructions for inspecting the wing attachment areas. Seamax Service Bulletin SB_001_09 dated February 3, 2009 provides instructions for a one-time visual inspection on bottom wing strut fitting ends. Seamax Service Bulletin SB_001_20 dated May 14, 2020 provides instructions for a repetitive visual inspection of the stainless-steel connection of wing strut to fuselage to be performed during all preflight checks.
 
Recommendations
 
The FAA recommends owners and operators of Seamax M-22 light-sport airplanes which incorporate the folding wing optional assembly perform the actions of Seamax Service Bulletins SB_001_09 dated February 3, 2009 and SB_001_20 dated May 14, 2020. The FAA also recommends that owners and operators repetitively inspect the wing strut hinge points, as shown in Figures 1 and 2, to ensure proper installation and attachment of the nuts prior to every flight.

                                                                        ILLUSTRATION (Figure 1)

                                                                        ILLUSTRATION (Figure 2)

For Further Information Contact
 
John Stoll, Light Sport Aircraft Program Manager, Production and Airworthiness Systems (AIR-632), FAA Policy and Innovation Division at John.Stoll@faa.gov
 
Or Kristi Bradley, General Aviation Safety Coordinator, Fleet Safety Section (AIR-723), Compliance and Airworthiness Division at Kristin.Bradley@faa.gov