Airworthiness Directives; Jetstream Aircraft Limited HP137 Mk1, Jetstream Series 200, and Jetstream Models 3101 and 3201 Airplanes

الملخص

This document proposes to revise an earlier proposed airworthiness directive (AD), which would have superseded AD 81-20-01. That AD currently requires repetitively inspecting the nose landing gear (NLG) actuator support structure and the front pressure bulkhead for cracks on Jetstream Aircraft Limited (JAL) HP137 Mk1 and Jetstream series 200 airplanes, and replacing any cracked part. The previous document would have: retained the repetitive inspections required by AD 81-20-01; required repetitively inspecting the NLG retraction jack upper mounting fitting and attachment hardware for security bolt failure and for bolts with improper torque levels on the HP137 Mk1, Jetstream series 200, and Jetstream Model 3101 airplanes; required replacing any failed security bolts and adjusting any bolt with an improper torque level; and required modifying the NLG retraction jack on all affected airplanes as terminating action for the repetitive inspections. As currently written, the document allows continued flight if cracks are found in the front pressure bulkhead membrane and actuator support structure when cracks do not exceed certain limits. Since publication of that proposal, the Federal Avia