Airworthiness Directive · Amendment 39-21800 · Fire protection
De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
This AD applies to De Havilland Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes, certificated in any category, serial numbers 4001 and 4003 through 4614 inclusive.
The FAA is adopting a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-401 and - 402 airplanes. This AD was prompted by reports of loss of hydraulic fluid and annunciation of the check fire detect light. This AD requires doing a detailed visual inspection for chafing and proper clearance of the left-hand (LH) and right-hand (RH) main landing gear (MLG) primary zone advanced pneumatic detector (APD) sensing lines, the hydraulic tube assemblies, and the surrounding structure, and doing all applicable corrective action. The FAA is issuing this AD to address the unsafe condition on these products.
Within 48 months or 8,000 flight hours, whichever occurs first after the effective date of this AD: Do a detailed visual inspection for chafing and proper clearance of the left- and right-hand MLG primary zone APD sensing lines, the hydraulic tube assemblies and the surrounding structure, and do all applicable corrective actions, in accordance with paragraph 3.B. of the Accomplishment Instructions of De Havilland Aircraft of Canada Limited Service Bulletin 84-26-20, Revision A, dated March 9, 2021. Do all applicable corrective actions before further flight.
