Inspection and Replacement of Exhaust Installation

URGENT

*TB 1-1730-229-30-1

DEPARTMENT OF THE ARMY TECHNICAL BULLETIN

Aviation Ground Power Unit (AGPU)

Part Number 83-360A, NSN 1730-01-144-1897

Part Number 83-360D, NSN 1730-01-466-9371

Headquarters, Department of the Army, Washington D. C.

16 July 2003

DISTRIBUTION STATEMENT A: Approved for public release, distribution is unlimited.

NOTE

THIS PUBLICATION IS EFFECTIVE UNTIL RESCINDED OR SUPERSEDED.

1. PURPOSE. The purpose of this TB is to identify AGPUs that have leaking or defective exhaust

ejector assemblies and to authorize replacement of the original and modified ejector and inlet tube

assemblies with a new improved performance exhaust deflector installation. The new installation further

reduces the gas turbine engine (GTE) exhaust backpressure, yet maintains better draw to cool the

engine/generator compartment and the hydraulic fluid. Reduction in the exhaust backpressure increases

the available shaft horsepower, increases the pneumatic output, reduces the exhaust gas temperature,

and reduces the specific fuel consumption of the AGPU.

2. PRIORITY CLASSIFICATION. URGENT.

3. SUMMARY OF PROBLEM.

a. There have been reports that the AGPU exhaust ejector plenum have cracked or corroded to a

point that exhaust gas is leaking into the engine/generator compartment causing additional

corrosion.

b. Flu inlet tubes have broken free from the support plate and blown out of the flu.

The current GTE exhaust ejector installation causes excess backpressure that adversely affects

engine performance. This can cause compressor stall/surge at high shaft horsepower (electric

and hydraulic outputs).

d. The modified exhaust ejector and inlet tube assembles do not have sufficient draw to adequately

cool the hydraulic fluid.

* This TB supersedes TB 1-1730-229-30-1, dated 15 May 2000.