FAA advises Lake Amphibian spar inspections

The possible structural problems affect Lake and Colonial amphibious aircraft models including the Colonial C–1 and C–2; Lake LA–4, LA–4A, LA–4P, LA–4-200; Lake Model 250; and Lake 270 Turbo Renegade.

While the FAA said it does not consider the problem a threat to safety that would warrant an airworthiness directive, the agency does recommend a series of inspections that owners and operators can perform.

The discovery of cracking in Lake and Colonial aircraft wings dates back 45 years, according to the FAA bulletin. During that time, members of the Lake Amphibian Club recorded around 27 reports of cracks in wing rear spar webs that could be seen in the aircraft wheel wells. One report mentioned elongated bolt holes in fittings used to attach the wings to the fuselage.

Among the FAA’s recommended points of inspection are wing attachment hardware including bolts and rivets that could loosen, wear, corrode, or sustain other types of damage. Inspecting the wing tips and rocking the wings fore and aft are suggested methods for spotting damage and looseness in the wing attachments.

The FAA said the recommended checks can take place during preflight, annual, or 100-hour inspections. The agency also recommends performing the inspection after incidents or accidents including water loops, impacts to the wing and landing gear that cause damage, and other situations in which the wing’s rear attachment area could have incurred torsional stresses greater than normal.

The FAA wants aircraft owners and operators to report what they find during inspections to the agency’s Service Difficulty Reporting System site. Pilots should also report findings to the Lake Amphibian Club online or by phone at 801-543-5801. In the absence of factory support, the club has long provided Lake Amphibian owners with resources regarding inspections, repairs, and general airworthiness issues.