Airworthiness Directive · Amendment 39-15644 · Bombardier Inc. Airplanes
Bombardier Inc. Airplanes
Superseded. A later AD replaced this one: AD 2010-14-16. Comply with the one in force.
This AD applies to Bombardier Inc. DHC-8-400 Series.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
The FAA is superseding an existing airworthiness directive (AD) that applies to certain Bombardier Model DHC-8-400 series airplanes. The existing AD currently requires revising the Limitations section of the airplane flight manual (AFM) to include procedures for pulling the "HYD PWR XFER'' circuit breaker in the event of the loss of all hydraulic fluid in the No. 1 or No. 2 hydraulic system. This AD requires a revision to the AFM to include additional procedures for ensuring that the "PTU CNTRL'' switch is Normal, the "PTU CNTRL ON'' advisory light is out, and the "HYD PWR XFER'' circuit breaker is pulled in the event of the illumination of the "2 HYD ISO VALVE'' caution light. This AD resulted from low No. 2 hydraulic pressure in-flight, which caused the power transfer unit to overspeed, and the fluid flow within the No. 1 hydraulic system to increase. We are issuing this AD to prevent possible loss of both the No. 1 and No. 2 hydraulic systems, resulting in the potential loss of several functions essential for safe flight and landing of the airplane. DATES: This AD becomes effective September 2, 2008. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of September 2, 2008. On July 10, 2007 (72 FR 30968, June 5, 2007), the Director of the Federal Register approved the incorporation by reference of certain other publications. We must receive any comments on this AD by September 15, 2008.
