Date: 201502
Aircraft: Cessna 150
Operator: Personal
Operating under: Part 91
Mission: Personal
Flight phase: Parked
Aircraft component: Pilot Seat
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Other Person
When detected: Aircraft In Service At Gate
Result: General None Reported / Taken
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: A Cessna 150 was flown for more than 60 hours beyond the due time for AD2011-10-09 while the operator falsely believed he was compliant with the airworthiness directive (AD) via an Alternative Method of Compliance (AMOC).AD2011-10-09 mandates the inspection of the seat rail mechanisms on the Cessna 150 (and many other Cessna aircraft) every 100 hours or 12 months whichever occurs first. Due to the high utilization of the Cessna 150 involved; the sole pilot and owner sought relief from the 100 hour inspection requirement. Approved AMOC L115W-11-986 extends the sub-annual inspection interval to 220 hours for aircraft not involved in for-hire or flight instruction ops (such as this aircraft). The individual owner and operator of the Cessna 150 sought to apply this AMOC (originally from the Cessna Aircraft Company).AD2011-10-09 includes the statement 'Before using any approved AMOC; notify your appropriate principal inspector; or lacking a principal inspector; the manager of the local flight standards district office/certificate holding district office.' As directed in the AD; and following a phone call with the local FSDO stating his intent; the owner then proceeded to fax a letter to the manager of the aircraft's FSDO stating his application of the AMOC to the airframe involved. Having notified the FSDO of his application of the approved AMOC; the owner then proceeded to operate the aircraft beyond 100 hours between seat rail inspections (but less than 220 hours). A subsequent phone call with the FSDO approximately 10 months later revealed that the owner or responsible Maintenance Technician should have received a letter approving the application of the AMOC from the FSDO before the aircraft changes its maintenance schedule. The aircraft had just had the necessary inspections detailed in the AD performed. As a corrective action going forward; the owner will comply with the AD as written (inspect every 100 hours) unless a letter specifically authorizing an alternative compliance is in hand.A contributing factor to this oversight was a lack of clear requirements for AMOC application in either the AD or the approved AMOC itself. AD's state that operators must notify the appropriate FSDO; but do not state that an official letter or paperwork must be received and on-hand prior to transferring/applying an already approved AMOC.




Synopsis: A pilot owner-operator reported that he had advised the FAA Flight Standard District Office of the desire to apply an Alternate Means of Compliance for an Airworthiness Directive. The owner-operator was advised later that he applied the change to the aircraft's maintenance plan prior to receipt of a letter of approval from the FSDO.