The FAA issued a Special Airworthiness Information Bulletin (SAIB) for owners of certain Piper PA-46 models after the recent discovery of fatigue cracking in the wing main spar lower cap in a Malibu Mirage.
According to the FAA, during routine inspection of the PA-46-350P, an inch-and-a-half-long crack was discovered in the main spar lower cap, later confirmed to be a fatigue crack. The FAA noted that the airplane has accumulated 5,273 hours time-in-service. Its type certificated life limit is 15,580 hours.
The SAIB includes the PA-46-310P, PA-46-350P, PA-46R-350T and PA-46-500TP models.
The FAA says no single cause for the cracking has been identified, but noted that the airplane was not in compliance with an existing lower wing rivet Service Bulletin (SB 796B), had non-conforming fasteners installed and was operated in “severe” environments.
The FAA recommends owners of affected airplanes ensure compliance with a number of wing spar SBs, including SB 796B – Lower Wing Rivet Replacement (PA-46-310P, PA-46-350P); SB 1204 – Re-calculation of Wing Structure Life Limit due to Unique Usage (PA-46-310P, PA-46-350P, PA-46R-350T, PA-46-500TP); and SB 1271 – Wing Spar Inspection (PA-46-310P, PA-46-350P, PA-46-500TP).
Any damaged components should be repaired or replaced and reported to the FAA.
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