EFFECTIVITY
ALL CFM56 ENGINES
CFMI PROPRIETARY INFORMATION
CFM56-ALL
TRAINING MANUAL
HIGH PRESSURE
COMPRESSOR
BORESCOPE
INSPECTION
Page 92
Sep 03
HIGH PRESSURE COMPRESSOR (HPC)
(ALL) :
HPC rotor blade damage may occur after the engine
experienced an abnormal operating problem. The
following list provides examples of conditions where
a complete HPC borescope inspection should be
performed:
- HPC stall
(this may occur during engine acceleration).
- Foreign Object Damage (FOD).
- High level of N2 rotor vibration.
- N2 rotor overspeed.
- Heavy landing.
- Oil fumes detected in cabin air.
Alignment rod.
The HPC stator vanes may move slightly, causing
misalignment of the borescope port and the
corresponding hole in the stator. If it is impossible to
introduce the probe into the port, use an alignment rod to
realign the stator vane segment.
Refer to the AMM for more information.
General inspection method.
To inspect the blades, it is necessary to open the VSV’s.
Refer to the appropriate procedure in the AMM.
Inspection starts with stage 1 rotor, through port S1.
Probe No 2 (yellow) is used for a general inspection of
the blades.
Probes No 3 (green) and No 4 (blue) may be necessary
for defect assessment.
Probe No 3 is used to inspect the L/E platform area and
probe No 4 to inspect the L/E blade tip area.
Repeat the same method for ports S2 to S9.
Map the defects on the special reporting form.
TOC
