A month after a Cessna Skymaster crashed in New Jersey when a six-foot section of the outboard right wing separated from the aircraft, the FAA has issued a special airworthiness information bulletin (SAIB) with some safety recommendations for Cessna 336 and 337 aircraft.
The accident aircraft had extended wingtips installed with a supplemental type certificate (STC), and it also had an STC for winglets.
The FAA recommends that pilots follow published airspeed and maneuvering limitations for aircraft that are modified and to watch for “excessive ‘bowing’ of the tip extensions in flight.” Aircraft owners are encouraged to do a one-time inspection of the wings for internal and external damage to certain sections of the wing within the next 100 hours. The SAIB lists seven areas to focus on during the inspection.
If more than one STC installation has been made on the aircraft, the FAA asks that aircraft owners add the notation: “This approval should not be extended to aircraft of this model on which other previously approved modifications are incorporated unless it is determined that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft.”
While SAIBs are not mandatory, pilots and aircraft owners are encouraged to comply with the recommendations.