Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
A stub axle failure of the main landing gear on a Dornier 228- 200 aeroplane was reported to RUAG Aerospace. Investigations revealed that the fracture of the axle--manufacturer Part Number (P/ N) A-511000B28B was due to fatigue. Already in the year 1993 two failures of P/N A-511000B28B axles occurred. Those events led in 1994 the Luftfahrt-Bundesamt--Germany's National Aviation Authority--to publish Airworthiness Directive (AD) D-1994-042 to mandate the replacement of A-511000B28B axles by improved-design axle with P/N A-511000C28B (Dornier Luftfahrt GmbH Service bulletin 228-214). It is believed that a misinterpretation of the Dornier 228 repair/maintenance documentation caused inadvertent installation of A-511000B28B axle on the accident aeroplane's main landing gear with P/N A-511000C00F. This configuration was not approved for installation and was therefore not addressed by LBA AD D-1994-042 or Dornier SB-228-214. The actions specified in this Airworthiness Directive are intended to prevent main landing gear failure, which could result in loss of control of the aeroplane during landing operations.
The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.