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Honeywell Issues Service Bulletin For Painting of Bypass Ducts

July 2023

To mitigate and/or address instances of corrosion and pitting found in the inner and outer bypass ducts and supports, Honeywell issued Service Bulletin AS907-72-9064 on June 12, 2015, on the following engines:

  • AS907-1-1A (Bombardier Challenger 300)
  • AS907-2-1G (Gulfstream G280)
  • AS907-2-1A (Bombardier Challenger 350)

This SB will inspect and evaluate for corrosion and pitting of the FWD and AFT Ducts as well as the Core Cowls. If corrosion is noted, we will perform a repair to add another coat of paint as a preventive barrier for future contamination.

Because this SB requires the removal of the forward and aft outer fan bypass duct(s) and mid and aft inner fan duct panels, it should be scheduled during a maintenance event that will have the aircraft down for seven to 10 days.

For Bombardier Challenger 300 Aircraft: SB AS907-72-9044

If you haven't complied with Honeywell SB AS907-72-9044 that replaces the engine combustion chamber assembly, I recommend you ask to have SB AS907-72-9064 put on your work scope so these items can be evaluated at that time for corrosion.  Most of these panels and ducts will be removed during the work scope of 72-9044.

For any questions about these SBs or your AS907 engine, contact me anytime.


SCHSH Shawn Schmitz Engine Tech Rep Astra, Challenger, Citation, Embraer, Falcon, Global, Gulfstream, Hawker, King Air, Learjet, Westwind Lincoln, NE (LNK) +1 402.479.8166

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