Airworthiness Directive · Amendment 39-18294 · Electrical power
Bombardier, Inc. Airplanes
This AD applies to Bombardier, Inc. Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 airplanes, certificated in any category, serial numbers 003 through 672 inclusive.
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This AD was prompted by reports of un-annunciated failures of the direct current (DC) starter generator, which caused caution indicators of the affected systems to illuminate and prompted emergency descents and landings. This AD requires replacing the DC generator control units (GCUs) with new GCUs and replacing the GCU label. We are issuing this AD to prevent a low voltage condition on the left main DC bus, which, during critical phases of flight, could result in the loss of flight management, navigation, and transponder systems, and could affect continued safe flight.
Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first, accomplish the actions specified in paragraphs (g)(1) and (g)(2) of this AD, as applicable.
(1) For airplanes having Goodrich DC GCU part number 51539-008B, 51539-008C, or 51539-008D installed: Incorporate Bombardier Modification Summary (ModSum) 8Q101925 by replacing the GCU with a new GCU, and replacing the GCU label, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 8-24-89, Revision C, dated November 4, 2014.
(2) For airplanes having Phoenix DC GCU part number GC-1010-24-5DIII or GC-1010-24-5DII installed: Incorporate Bombardier ModSum 8Q101710 by replacing the GCU with a new GCU, and replacing the GCU label, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 8-24-84, Revision D, dated April 10, 2014.
For airplanes having Phoenix DC GCU part number GC-1010-24-5DIV or GC-1010-24-5DV installed: Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first, replace the DC GCU label with a new GCU label, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 8-24-84, Revision D, dated April 10, 2014.
