Airworthiness Directive · Amendment 39-18241 · Landing gear
Bombardier, Inc. Airplanes
Superseded. A later AD replaced this one: AD 2021-10-13. Comply with the one in force.
This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and-402 series airplanes, certificated in any category, serial numbers 4001 through 4448 inclusive.
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted by an in-service report of an uncommanded and unannunciated nose wheel steering during airplane pushback from the gate. This AD requires installing new cable assemblies with a pull-down resistor. We are issuing this AD to prevent an uncommanded nose wheel steering during takeoff or landing in the event of an open circuit in the steering system, and possible consequent runway excursion.
Within 2,000 flight cycles or 12 months after the effective date of this AD, whichever occurs first: Incorporate Bombardier Modsum 4-126585 to install new cable assemblies, with a pull-down resistor, in accordance with paragraph B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-32-122, Revision A, dated October 4, 2013.
