Airworthiness Directive · Amendment 39-17243 · Electrical power
Bombardier, Inc. Airplanes
This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes, certificated in any category, serial numbers 4001 and subsequent.
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes. This AD was prompted by reports of an in-service incident where the propeller de- icing system became unavailable due to burnt/chafed wires within the alternating current contactor box (ACCB). This AD requires inspection for chafing, damage, and loose wiring within an ACCB and repair if necessary; and requires rework and re-identification of the wiring installation within each ACCB. We are issuing this AD to detect and correct damaged, chafed, or loose wiring within an ACCB, which could affect the operation of the windshield heater, ice detector, angle of attack (AOA) vane heater, pilot probe heater, engine intake heater, or propeller de-icing system, and subsequently adversely affect the airplane's flight characteristics in icing conditions.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For airplanes having serial numbers 4001 through 4354 inclusive, and 4356 through 4366 inclusive: Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first: Do a general visual inspection for chafing, damage, and insulation damage, and rework the wiring within the ACCB, in accordance with the Accomplishment Instructions of the applicable Bombardier service bulletin specified in paragraphs (g)(1) through (g)(4) of this AD. If any chafing, damage, or insulation damage is found, before further flight, replace the damaged wiring, in accordance with the Accomplishment Instructions of the applicable Bombardier service bulletin specified in paragraphs (g)(1) through (g)(4) of this AD.
(1) Bombardier Service Bulletin 84-24-47, Revision A, dated September 14, 2011.
(2) Bombardier Service Bulletin 84-24-48, Revision A, dated September 14, 2011.
(3) Bombardier Service Bulletin 84-24-49, Revision A, dated September 14, 2011.
(4) Bombardier Service Bulletin 84-24-50, Revision A, dated September 14, 2011.
