The FAA on Tuesday posted its official notice that it is reopening the comment period on its proposed Cessna wing-spar Airworthiness Directives, and also announced that it will hold a public meeting on the matter in March. The Regional Air Cargo Carriers Association (RACCA) said in its January newsletter the AD would virtually destroy the economic viability of older C-402 aircraft. "The cost of the wing-structure modification represents a large percentage of the aircraft's total market value," RACCA said. An ad hoc owners' group called the Cessna Twin Spars Corp. argues that the rules will cost $43,100 per airplane to implement, and they want time to develop safe and economical alternative means of compliance. The FAA will hold the public meeting on March 3 and 4, starting at 9 a.m. both days, at the Hilton at Washington Dulles Airport, in Herndon, Va. Comments on the proposed rules will be accepted until April 5. RACCA asked Cessna for recorded instances of wing failures, cracking in primary wing structures, and the propagation of primary structure cracks appearing in properly maintained aircraft. Robert Vila, president of the Cessna Twin Spars Corp., told AVweb his group's efforts are hampered by the lack of Cessna data, which the company is withholding as proprietary information. "Without the Cessna data to review, our organization would have to replicate the testing and computer modeling that Cessna has already accomplished," Vila said. The group also warns that although the current AD proposal affects only 400-series twins, it expects that other Cessna twins are likely to be subjected to similar ADs.