Airworthiness Directive · Amendment 39-19581 · Landing gear
Bombardier, Inc., Airplanes
This AD applies to Bombardier, Inc., Model BD-100-1A10 airplanes, certificated in any category, serial numbers 20002 through 20744 inclusive.
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was prompted by an incident of uncommanded nose wheel steering (NWS) in-service; subsequent investigation revealed that the steering selector valve (SSV) is susceptible to jamming in the open position due to particulate contamination of the hydraulic system. This AD requires modifying the left-hand hydraulic system of the NWS control system and, for certain airplanes, torqueing the fittings on a certain tube assembly. We are issuing this AD to address the unsafe condition on these products.
Except for airplanes identified in paragraph (h) of this AD: Within 2,000 flight cycles or 60 months after the effective date of this AD, whichever occurs first, modify the left-hand hydraulic system of the NWS control system by installing a hydraulic filter into the hydraulic line between the direct current motor pump and the SSV, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 100-32-31, Revision 03; or Bombardier Service Bulletin 350-32-007, Revision 03; both dated March 27, 2018; as applicable.
For airplanes that have incorporated Bombardier Service Bulletin 100-32-31, dated January 4, 2018; Bombardier Service Bulletin 100-32-31, Revision 01, dated January 23, 2018; Bombardier Service Bulletin 100-32-31, Revision 02, dated March 14, 2018; Bombardier Service Bulletin 350-32-007, dated January 4, 2018; Bombardier Service Bulletin 350-32-007, Revision 01, dated January 23, 2018; or Bombardier Service Bulletin 350-32-007, Revision 02, dated March 14, 2018; as applicable, as of the effective date of this AD: Within 50 flight hours after the effective date of this AD, torque the fittings on any tube assembly having part number K1000070395-401, in accordance with the “Retroactive Action” instructions of Bombardier Service Bulletin 100-32-31, Revision 03, or Bombardier Service Bulletin 350-32-007, Revision 03, both dated March 27, 2018, as applicable.
