NTSB Safety Recommendations

The National Transportation Safety Board recommends that the Federal Aviation Administration:

Require all operators of PT6A-34, -35, and -36 engines, including those using on-condition maintenance programs, to incorporate the reliability standards, particularly those concerning life-limited components, noted in the most current service bulletin into their engine maintenance programs. (A- 09-108)

Evaluate the effectiveness of the Portland Flight Standards District Office’s surveillance of maintenance programs and implement necessary changes so that inadequate maintenance programs are identified and improved. (A-09-109) Resolve the differences between Advisory Circular (AC) 120-17A and AC 120-16E in regard to Federal Aviation Administration philosophy and use of on-condition maintenance programs. (A- 09-110)

Once the differences noted in Safety Recommendation A-09-110 are resolved, review existing on-condition maintenance programs to ensure that they are compatible with the most current accepted philosophy. (A-09-111)