The FAA has issued an emergency AD mandating the immediate inspection of the left-hand elevator auxiliary spar on De Havilland DHC-3 Otters a month after an Otter floatplane crashed in Washington State, killing all 10 people onboard. The AD was issued Oct. 4 after “multiple recent reports of cracks” in the spar, the FAA said. “The unsafe condition, if not addressed, could result in elevator flutter leading to elevator failure, with consequent loss of control of the airplane,” the AD says. Although there’s no suggestion in the AD that it was prompted by the accident, witnesses reported the aircraft suddenly dove into the water in Mutiny Bay, just off Whidbey Island, last Sept. 4.
The emergency AD requires “repetitive detailed visual inspections of the entire left-hand elevator auxiliary spar for cracks, corrosion, and previous repairs, and depending on the findings, replacement of the left-hand elevator auxiliary spar. This AD also requires sending the inspection results to the FAA.” The type certificate for the Otter is held by Canadian manufacturer Viking Air and Transport Canada, which has been consulted about the AD.