Honeywell TFE731: Accessory Gearbox Carbon Seal Improvements

September 2014

If you fly with Honeywell TFE731-20,-40,-50,-60 engines, you may have noticed oil leaking from the accessory gearbox drive cover. More specifically, from the starter and alternator gearshaft air-oil seals (P/N 3072784-2).

This is due to high heat that produces coking and carbon build up on the seals.

Honeywell is aware of this and in March of this year released Service Bulletin (SB) TFE731-72-5227 that introduces a reconfigured accessory gearbox cover and a new hydrodynamic carbon face seal that will reduce starter and alternator gearshaft leaks.

These changes now require shimming the gearshafts to ensure they are properly positioned when the gearbox is assembled.

Compliance of this SB will change the accessory gearbox assembly part number from PN 3060827-2 to PN 3060827-4.

Honeywell recommends you incorporate this bulletin during your next scheduled Compressor Zone Inspection. Under certain conditions, a special/warranty program may be available for this modification. Consult the SB for details.

The following SBs should be complied with prior to or at the same time as SB TFE731-72-5227

  • TFE731-72-5124: Install/Rework Accessory Drive Gearbox
  • TFE731-72-5216: Install Improved Plain Encased


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

Related Tech Articles

Talking To The Principal About Comparing Quotes
February 2021

Addressing Component Discrepancies During A Prebuy
September 2020

BendixKing RDR-2000 to RDR2060 Weather Radar Upgrade Program
June 2020

Calibration Laboratory Fulfills A Need For Aviation FBOs
September 2019

Ignoring Bleed Air Leaks Could Have Consequences
June 2019

View All Components Repairs Tech Articles