CFM Oil Temperature Sensor

航空

游客，如果您要查看本帖隐藏内容请回复

航空

Oil
Temperature
Sensor
Oil Temperature Sensor
• Oil T° Sensor
Disengagement
- Background
• Investigation
• Product Improvements
• In-service Plan
- Interim
- Final
• Summary
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 3
Oil Temperature Sensor
Background
• Five commanded IFSD’s in 2001
• Oil Temperature Sensor disengaged from housing
- All the oil expelled from the open port
• Event engines age less than 850 cycles since new
• Events led to extensive engine damages (bearings
failure)
- Low oil pressure warning delayed due to invalid PEO
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 4
Oil Temperature Sensor
Oil T° Sensor
Oil T° Sensor Housing
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 5
Investigation
• TEO Sensor with attachment bolts and self locking inserts
disengaged all together
• Housing threads found sheared
• 2,000 engines have been delivered with Housing P/N 340-
091-804-0
• Oil pressure cyclic load on the probe  back off the probe
Oil Temperature Sensor
Root Cause Understood: Lack of Robustness of the
Housing/insert Design  Sensitive to Over Torque
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 6
Failure Mode
Insert
Bolt
Housing
sheared
threads
Oil Temperature Sensor
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 7
Product Improvements
• New insert definition implemented (P/N 340-091-
805-0)
- Six (6) threads are engaged instead of three (3)
- On engines since May 2001 (engine 88T-481 and up)
- SB 72-0298 issued on July 5, 2001
• EEC Software
- Lower limit for PEO signals reduced
- Introduced in 7BM1 software (1853M79P20)
- S/B 73-0064 issued on July 31, 2001
Oil Temperature Sensor
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 8
In-service Plan
• Containment Plan
- Implementation of lockwire to secure the probe onto the housing
- For engines with less than 1,000 cycles since new
- S/B 72-A0336 issued on June 26, 2001
• Interim Plan
- Implementation of lockwire on all field engines regardless of age
- S/B 72-0372 issued in March 2002
Oil Temperature Sensor
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 9
Lockwire to secure
Oil T° Sensor onto
Oil Sensor Housing
Oil Temperature Sensor
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 10
In-service Plan
• Final Fix
- Mechanical final fix implementation during engine shop visit
- Install the new housing configuration (P/N 805)
Or
- Install a current/reworked housing (P/N 804 -> P/N TBD)
- Valid for a non damaged housing
- Rework to be released 2nd quarter 2002
- S/B 72-0298 to be revised in 2nd quarter 2002
Oil Temperature Sensor
CFM56 Operators Conference – May 22 - 23, 2001 CFM Proprietary Data Unauthorized Disclosure Prohibited 11
• Five in-service events (IFSD’s)
• Root cause is the lack of Housing/Insert design robustness
• New insert introduced in production (P/N 340-091-805-0)
• Interim field plan is to implement Lockwire on all engines
- SB72-0372 issued in March, 2002
• Final In-service plan is to replace or repair old Housing
- Repair, and SB to be issued in 2Q 2002
Oil Temperature Sensor Summary

979199501

CFM56-7 Starter Reliability

kinran

08032135

bocome

CFM Oil Temperature Sensor