Twin Commander's Isley Comments on Corrosion NPRM

 - September 23, 2009, 11:12 AM

The FAA has issued a Notice of Proposed Rulemaking for an Airworthiness Directive (AD) based upon Twin Commander Service Bulletin SB237. The proposed AD would require inspecting for corrosion between the mating surfaces of the upper wing skin and engine mount support straps on Twin Commander Models 690, 690A and 690B. As proposed, compliance is required within 12 months of issuance or at the next 150-hour inspection, whichever comes first. Matt Isley, president of Twin Commander Aircraft, told AIN that many operators have already complied. “Given the risk of wing structure damage if performed improperly, we recommend using one of our own authorized service centers,” he said. For those who use another service provider, Isley said an A&P can perform the inspection, but a factory-trained technician is required during the strap replacement. “While most of our 21 factory-authorized service centers can perform the work, half of the 48 technicians who received training represent non-network service centers. Therefore, accessibility should not be an issue domestically or internationally.” The FAA is soliciting feedback on the proposed AD until October 13.