ATA 30

Upgraded Engine HP Bleed Manifold Pipe
Recently, a Westwind operator discovered damage to the aluminum bypass duct of a 731-3 engine. Upon further investigation, the cause was determined to be a failed HP bleed manifold assembly, P/N F10A5P20242-7, with the subsequent hot bleed air damaging the fan bypass ducts that cannot be repaired. The failure occurred near the 12:00 plenum mount boss.

Israel Aircraft Industries (IAI) issued Service Information Letter (SIL) 1124-30-080, dated May 29, 1990,informing operators of the availability of a new bleed manifold assembly, P/N F10A5P20242-9. The –9 is made from an F10A5P20242-7 bleed manifold assembly with reinforcement saddles welded in the area where the engine anti-ice line attaches. Refer to the 1124 Illustrated Parts Catalog, Chapter30-20-00 for the upgraded –9 tube assembly.

We would like to remind operators of the availability of the F10A5P20242-9 bleed manifold assembly and that the Maintenance Manual, Chapter 5-20-07 maintenance practices call out a 200-hour inspection interval of the engine, nacelle, and pylon.
Step 1.E. provides specific instructions to inspect the low- and high-pressure bleed ducts for leaks, cracks, fit, and general condition. Additionally, it has a note instructing the operator to inspect the manifold assembly during an engine Major Periodic Inspection or whenever the after body is removed. The bypass duct should also be inspected for any discoloration of the shroud. The flight crew will notice a rise in Interstage Turbine Temperature (ITT) if a manifold assembly has failed.