Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. 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:
Late in 2002 the manufacturer advised CASA of another Nomad accident which was possibly caused by aileron flutter with the flaps at 38 degrees. This, along with the other flutter incidents, has resulted in the manufacturer issuing ANMD-57-18 Issue 1 as a precautionary measure while they further investigate the issue.
The manufacturer has now completed their investigation and issued Alert Service Bulletin ANMD-27-53 to modify flap actuation linkages to restore the necessary rigidity to the outboard flap, and hence the aileron. The unacceptable flexibility of the outboard flap mechanism allows flutter to occur in extreme circumstances.
The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.