Available for sale is a Honeywell GTCP331-350C APU offered in as-removed / unserviceable condition, supported by a detailed Honeywell shop findings and teardown report.

The unit was removed following metal contamination detected in the oil system, with subsequent inspection confirming a cooling fan thrust bearing failure, which led to gearshaft shearing and extensive internal damage to the cooling fan assembly.

Further teardown and inspection revealed that the power section, gearbox, and cooling fan were fully disassembled, with the load compressor sent to vendor for repair.

Condition Summary

Removal Reason: Metal contamination on magnetic chip detector

Primary Failure: Cooling fan thrust bearing failure (root cause of major damage)

Oil System: Metal chip contamination in gearbox sump and filter

Cooling Fan: Severe internal damage and heavy rub (confirmed with photos in report)

Gearbox: Structural impact including sheared components due to failure sequence

Load Compressor: Impeller-to-shroud rub observed

Thermal Blankets: Fretting observed

Additional Findings:

Heat shield lockwire button torn out

Outer transition liner shield overheated

Technical Details

Manufacturer: Honeywell

Model: GTCP331-350C

Serial Number: R-638C

Part Number: 3800454-6 (post-mod configuration)

Maintenance Facility: Honeywell Aerospace GmbH (EASA Part-145)

Workscope & Tear Down Status

Complete disassembly of:

Power section (heavy workscope)

Gearbox (medium workscope)

Cooling fan (full inspection)

Full inspection carried out per CMM and OEM manuals

Final test performed following heavy repair procedures

Commercial Assessment (Key Buyer Insight)

Unserviceable / teardown condition

Ideal for:

Part-out / component recovery

MRO repair evaluation

Core acquisition for exchange programs

Major damage concentrated in:

Cooling fan assembly

Oil-contaminated systems

Remaining modules (select components) may retain salvageable value depending on inspection