Airworthiness Directive · Amendment 39-16040 · Hamilton Sundstrand Power Systems T-62T-46C12 Auxiliary Power Units
Hamilton Sundstrand Power Systems T-62T-46C12 Auxiliary Power Units
This AD applies to Hamilton Sundstrand Power Systems T-62T-46C12 auxiliary power units (APUs). These APUs are installed on, but not limited to, Bombardier Inc. DHC-8-400 series airplanes.
The FAA is adopting a new airworthiness directive (AD) for Hamilton Sundstrand Power Systems T-62T-46C12 auxiliary power units (APUs). This AD requires upgrading the software in the APU full- authority digital controller (FADEC) from software version 02.01.000 to version 03.00.000. This AD results from two reports of APU compartment explosions due to over-fueling of the APU at low revolutions-per-minute during the start sequence. We are issuing this AD to prevent over- fueling of the APU during the start sequence, which could lead to fuel explosions, injury, and damage to the APU and the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
At the next FADEC removal, but no later than 18 months after the effective date of this AD, upgrade the software in the APU FADEC from software version 02.01.000 to version 03.00.000, and change the FADEC part number (P/N) from 4503069E to 4503069F.
(g) Use paragraphs 3.A through 3.F.(2) of the Accomplishment Instructions of Hamilton Sundstrand Power Systems Service Bulletin No. 4503067-49-12, Revision 2, dated March 9, 2009, to do the software upgrade and the FADEC P/N change.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Appliances and equipment
