EASA AD 2020-0140
Propeller — Gearbox Tooth Belt — Inspection / Time Limits / Maintenance Checks — Airworthiness Limitations Section Chapter 4 — Amendment
Summary
EASA Airworthiness Directive 2020-0140 is an amendment addressing the inspection, time limits, and maintenance checks of the propeller gearbox tooth belt on Stemme AG TSA-M powered sailplanes (models S6 and S6-RT) and ASP S15-1 aeroplanes. It mandates inspection and possible re-identification of the tooth belts, along with implementation of revised life limits as specified in the applicable Airworthiness Limitations Section (ALS) of the Stemme Aircraft Maintenance Manual. This directive ensures continued airworthiness by updating maintenance requirements for these specific aircraft models.
What Changed
This directive introduces a one-time inspection of the propeller gearbox tooth belts to identify parts marked 'Carbon' which have a reduced life limit compared to previous versions marked 'Extreme'. It requires operators to update the part number and implement the new life limits as specified in the updated ALS and Stemme Service Bulletin. Additionally, it mandates revising the Aircraft Maintenance Programme within 12 months to incorporate these new limitations.
Why It Matters
The directive is critical for aviation professionals because failure to comply with the updated inspection and life limits could lead to unsafe conditions due to premature tooth belt failure. Operators and maintenance organizations must ensure the correct identification and timely replacement of these parts to maintain aircraft safety and regulatory compliance. It also streamlines compliance by allowing AMP revisions to cover ongoing maintenance requirements without individual action records.
What To Do
Operators must inspect the propeller gearbox tooth belt within 25 flight hours or 30 days after 7 July 2020, whichever comes first, and re-identify any 'Carbon' marked belts before further flight. They must replace components before exceeding the new life limits and revise the Aircraft Maintenance Programme within 12 months to include the updated ALS limitations. Installation of 'Carbon' marked belts is permitted only if the part number has been updated as per the Service Bulletin instructions.
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