Rotax engine airworthiness directive superseded

October 6, 2010

The FAA has superseded an airworthiness directive (AD) on certain serial numbers of Bombardier-Rotax GmbH type 912 F and 914 F series reciprocating engines requiring initial and recurring inspections of crankcases for cracks.

The new AD requires those inspections, and includes the 912 S series in the AD. It adds a test procedure to determine engine suitability for a special flight permit, and changes applicability from the engine’s serial number to the crankcase serial number. The AD, issued to prevent oil loss and possible engine failure, takes effect Nov. 8.

Within 50 hours time in service from the AD’s effective date, a crankcase visual inspection must be performed. If the crankcase is cracked, the engine must be removed from service before further flight. Visual inspections of the engine crankcase for cracks must take place at each 100-hour, annual, or progressive inspection, or within 110 hours time in service since the last inspection, whichever occurs first.

The engines are installed on, but not limited to Diamond Aircraft Industries DA-20A1; and Diamond Aircraft Industries GmbH Models HK36TC, HK36TTC, HK36TTC-ECO, and HK36TTS aircraft.

The FAA estimates that the AD affects about 250 products of U.S. registry, and that it will take about three work hours per inspection, and 20 work hours to replace a crankcase. The average labor rate was estimated at $85 per work-hour. Required parts would cost about $6,500 per crankcase if crankcase replacement is deemed necessary.

Dan Namowitz

Dan Namowitz | Aviation Writer

Dan Namowitz is an aviation writer and flight instructor. He has been a pilot since 1985 and an instructor since 1990.