EFFECTIVITY
ALL CFM56 ENGINES
CFMI PROPRIETARY INFORMATION
CFM56-ALL
TRAINING MANUAL
LOW PRESSURE
TURBINE
BORESCOPE
INSPECTION
Page 150
Sep 03
LOW PRESSURE TURBINE (LPT)
(ALL) :
LPT rotor blade damage may occur after the engine
experienced an abnormal operating condition. The
following list provides examples of the conditions where
a complete LPT borescope inspection should be
performed:
- Engine stall (This may occur during engine
acceleration HPC, or deceleration LPC).
- Foreign Object Damage (FOD) and suspected bird
ingestion.
- High level of vibration on the N1 rotor.
- N1 rotor overspeed.
- Engine overtemperature.
- When flames are seen out of the nozzle during start
procedure.
Inspection areas.
On the LPT blades, there are 2 specific areas which are
dimensionally defined through section letters:
Area E (tip of the blade):
The portion of the blade airfoil starting from the
bottom of the tip shroud extending toward the
blade platform.
Area E (bottom of the blade):
Portion of the blade airfoil starting from the top of the
blade platform and extending toward the blade tip.
Other areas:
This is the remaining area of the blade which is all
leading and trailing edges, not including area E.
The following are inspection areas of the LPT rotor
blades and nozzles :
- Rotor blade leading and trailing edge.
- Rotor blade concave and convex surfaces.
- Hard face surface of the rotor blade tip shroud.
TOC