FAA Proposes New Airworthiness Directive for GE CF34 Engines After Crash
The AD would require the performance of restart tests and a borescope inspection of the HPC case, with potential for VG system functional checks and force gage tests.
The Federal Aviation Administration (FAA) has released a proposal for a new airworthiness directive (AD) for a variety of CF34 engines from General Electric Company (GE).
The proposed AD is for the following CF34 engine models:
- CF34-1A
- CF34-3A
- CF34- 3A1
- CF34-3A2
- CF34-3B
The FAA has suggested this AD following a crash resulting from a dual engine power loss, which prompted a manufacturer investigation showing corrosion in the high-pressure compressor (HPC) case. This corrosion affected the engine’s variable geometry (VG) system.
The AD would require:
- Restart tests
- Borescope inspection of the HPC case
Depending on the results of these tests, the AD would also mandate:
- VG system functional check for pressure evaluation
- Force gage test on feedback cable for tightness
- Visual inspection of VG system for obstruction
- Removing engine from service
To ensure the VG system functional check is performed consistently, the airworthiness limitations section (ALS) of the maintenance manual for these engines would also need revision.
