TFE731 Spring 2005

• New FAA Airworthiness Directive
• Initial Inspection for TFE731-2 and -2C Series Engines
• Repetitive Inspections for TFE731-2 and -2C Series Engines
• Disc Replacement for TFE731-3, -3A, -3AR, and -3R Series Engines
• Disc Replacement for TFE731-3B and -3BR Series Engines
• Optional Terminating Action
• Definitions

New FAA Airworthiness Directive

— Mike Healzer

The FAA has issued a new AD (2005-05-15) effective April 18, 2005, applicable to TFE731-2 and 2C series, and TFE 731-3, 3A, 3AR, -3B, -3BR, and -3R series turbofan engines. Affected engines must have one of the following low pressure turbine (LPT) stage 1 disc part numbers (p/n) installed: 3072070-all, 3072351-all, 3073013-all, 3073113-all, 3073497- all, and 3074103-all. “All” denotes all dash numbers installed.

Engines are installed on, but not limited to: Avions Marcel Dassault Falcon 10 and Mystere Falcon 50 series, Learjet 31, 35, 36, and 55 series, Lockheed-Georgia 1329-25 series, IAI 1124 series and 1125 Westwind series, Cessna Citation models III & VI, Raytheon British Aerospace HS-125 series and Sabreliner NA-265-65.

This AD is the result of an uncontained failure of the LPT stage 1 disc installed in a TFE731-3-1H turbofan engine.

Initial Inspection for TFE731-2 and -2C Series Engines

For the affected TFE731-2 and -2C engines, at the next MPI or at next access to the LPT stage 1 nozzle assembly, after the effective date of this AD, whichever occurs first, but not to exceed 2,200 hours time-in-service (TIS) since the last LPT stage 1 nozzle assembly inspection, do the following:

1. Measure throat dimensions, air flow, and determine serviceability of the LPT stage 1 nozzle per SB TFE731-72-3369RWK; and
2. If necessary, adjust the LPT stage 1 nozzle per SB TFE731-72- 3369RWK, Revision 6, or replace with a serviceable LPT stage 1 nozzle assembly.

Repetitive Inspections for TFE731-2 and -2C Series Engines

Thereafter, at every MPI, but not to exceed 2,200 hours TIS since the last LPT stage 1 nozzle assembly inspection, do the following:

1. Measure throat dimensions, air flow, and determine serviceability of the LPT stage 1 nozzle per SB TFE731-72-3369RWK, Revision 6; and
2. If necessary, adjust the LPT stage 1 nozzle assembly per SB TFE731-72- 3369RWK, Revision 6, or replace with a serviceable LPT stage 1 nozzle assembly.

Disc Replacement for TFE731-3, -3A, -3AR, and -3R Series Engines

For affected TFE731-3, -3A, - 3AR, and -3R engines, replace the LPT stage 1 disc with a serviceable disc, at next MPI, or at next access to the LPT stage 1 nozzle assembly, or before December 31, 2011, whichever occurs first.

Disc Replacement for TFE731-3B and -3BR Series Engines

For TFE731-3B and -3BR engines, do the following:

Replace LPT stage 1 disc, P/N 3073497-all, with a serviceable LPT stage 1 disc, at next MPI, or at next access to the LPT stage 1 nozzle assembly, or before December 31, 2011, whichever occurs first. Convert the TFE731-3B and -3BR engines to a TFE731- 3C engine. This conversion installs a serviceable LPT stage 1 disc.

Optional Terminating Action

As optional terminating action to the repetitive inspections required by this AD, replace the applicable LPT stage 1 disc with a more robust serviceable disc. Information on installing a serviceable disc can be found in SBs TFE731-72- 3704, TFE731-72-3705, and TFE731-72-3706.

Definitions

1. Next access to the LPT stage 1 nozzle assembly is defined as when the low-pressure tieshaft is unstretched.
2. A serviceable LPT stage 1 disc is defined as a disc having a part number not listed in this AD.
3. A serviceable LPT stage 1 nozzle assembly is defined as an LPT stage 1 nozzle that passes the acceptance referenced in this AD.

Please contact our TFE731 Technical Representatives for assistance with this or any other engine technical issue:

• LNK: Lanny Renshaw 800.228.4277
• BTL: Ken Kuchenreuther 800.525.2376

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