AD: 2022-21-51 Prompted By Multiple Recent Reports Of Cracks In The Left-Hand Elevator Auxiliary Spar

Emergency Airworthiness Directive (AD) 2022-21-51 is sent to owners and operators of Viking Air Limited (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) Model DHC-3 airplanes.

This Emergency AD was prompted by multiple recent reports of cracks in the left-hand elevator auxiliary spar. The FAA’s analysis of these reports indicates that immediate AD action is warranted. The FAA is issuing this AD to detect and address cracks, corrosion, and previous repairs to the left-hand elevator auxiliary spar. The unsafe condition, if not addressed, could result in elevator flutter leading to elevator failure, with consequent loss of control of the airplane.  

The FAA has coordinated this issue with Transport Canada, which is the aviation authority for Canada. Transport Canada issued AD CF-2018-04, dated January 19, 2018 (Transport Canada AD CF-2018-04), which includes a requirement for inspecting elevator assemblies for corrosion. The FAA issued a notice of proposed rulemaking that published in the Federal Register on February 8, 2022 (87 FR 7059) in response to Transport Canada AD CF-2018-04, and is currently addressing comments. 

As an interim action, the FAA is issuing this Emergency AD, as a result of the recent reports, to mandate an inspection of the left-hand elevator auxiliary spar and replacement if necessary. 

FAA’s Determination: The FAA is issuing this AD because the agency has determined that an unsafe condition is likely to exist or develop in other products of the same type design.

AD Requirements: This 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.

FMI: www.regulations.gov