The FAA issued an Airworthiness Alert on June 27, 2019, out of its Wichita ACO Branch, calling for input from owners and operators of Cessna 177 Cardinal and 210 model aircraft regarding the potential for cracking in the wing carry-through spar.
The alert-level Concern Sheet stems from an accident report in Australia involving a Cessna 210 that suffered an in-flight wing separation on May 26 of this year. The preliminary investigation notes the wing fractured because of fatigue cracking inboard of the wing attachment lugs, from a “small corrosion pit,” according to the alert.
Textron Aviation had issued Mandatory Service Letters on June 24, 2019, that provide instructions for a close look at the spar—including an eddy-current inspection—on the 210 and Cessna’s other strutless single, the Cardinal. A past airworthiness directive in 2012 addressed a different issue in a different location, and the FAA stressed the importance of the inspection and subsequent care of any corrosion found in this area.
Further, the agency wants owners to share detailed information on instances of cracking found in the spar, including any that have been identified before. It also asks operators to report any issues with the ease of accessing the area for inspection, as well as general information regarding the time in service and other data on the fleet.
Because there are differences in the area in question between the two airplanes, the incidence of corrosion is expected to vary as well. Paul Millner, co-founder of the Cardinal Flyers Online, one of the type clubs contacted by FAA, notes, “The 210 has an upholstery pad that enhances corrosion; the Cardinal does not…but inspecting for and avoiding corrosion pits is only the wise thing to do.” None has, as of yet, been identified on Cardinals.
The information is requested through the 30-day alert period, to close at the end of July.