2021-25-12
FR doc 2021-27709 · 86 FR 72174AD 2021-25-12Published 2021-12-21Effective 2022-01-05
Superseded by 2024-12-05 Supersedes 2017-19-09
Supersedence is read from the Federal Register text of the newer AD — the FAA publishes no structured field for it — and names only ADs held in our index.
Requires repetitive lubrications of the trailing arm of the NLG.
Full official abstract
The FAA is superseding Airworthiness Directive (AD) 2017-19- 09, which applied to certain De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Model DHC-8-400 series airplanes. AD 2017-19-09 required modifying the nose landing gear (NLG) shock strut assembly. This new AD requires repetitive lubrications of the trailing arm of the NLG. This new AD also requires revising the existing maintenance or inspection program to include new and revised airworthiness limitations (life limits for certain bolts). This AD was prompted by reports of a certain bolt being found missing or having stress corrosion cracking. The FAA is issuing this AD to address the unsafe condition on these products.