The US Federal Aviation Administration filed a notice of proposed rulemaking for a proposed airworthiness directive (AD) regarding Diamond Aircraft Industries aircraft models DA42, DA42 NG and DA42 M-NG today.
The proposed AD is based off of mandatory continuing airworthiness information (MCAI) that originated from European Aviation Safety Agency (EASA) AD 2011-0100 on 26 May 2011.
The MCAI required operators to identify and correct an unsafe condition on these aircraft types, which it describes as "excessive voids in the adhesive joint between the centre wing spars and the upper center wing skins." The MCAI said that this condition could cause the wing to fail, which could lead to the loss of control of the aircraft.
The EASA AD said that voids in the adhesive joint between the centre wing spars and the upper center wing skins were detected during the conversion of a DA42 to a DA42 NG. These voids are located between the fuselage wall and the engine nacelle.
The EASA AD also said that wings with voids may continue to meet certification design limits, but they must be "within established criteria." The AD says that the wings that have voids exceeding these criteria have to be repaired. Diamond issued a document containing mandatory service bulletins 42-092 and 42NG-22 that describes how to inspect the wings of those aircraft.
The FAA will accept comments on this proposed AD for 45 days after 15 June.