CFM High Temperature Oil Issues

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February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 1
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 2
SFH Gasket Seal
High Temperature Oil Issues
CFM 56 OIL EXPERIENCE
(MOBIL JET OIL 291 ISSUE)
- Main O/F heat exchanger gasket seal
- Other issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 3
Experience with Standard (STD) Grade oils (MJO 2, EXXON 2380…) :
 Engine sump always remains free of oil coking
 Coke build up reported inside the aft sump oil supply and scavenge lines
– WPG recommendation in place to clean the affected lines at each
shop visit opportunity
AFT Sump Oil Lines Must Be Cleaned at Each Shop Visit Exposure
Oil Experience
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 4
Experience with High Thermal Stability (HTS) Oils (MJO 254, MJO 291, BPTO
2197) :
 Mobil MJO 254 has been in service for years now with no problem reported
 Mobil MJO 291 was approved for CFM 56 in Oct. 2000 after service
evaluation was conducted on two CFM56 -5B4/2P engines:
– These engines had accumulated 3000 H / 2250 C with MJO 291
– All oil wetted parts were found very clean
– Aft sump oil supply and scavenge lines found with a thin coke deposit
(no significant coke build-up)
– All inspected elastomeric and carbon seals were found in good
condition
– Oil analysis monitoring performed: no change in viscosity and TAN
Oil Experience
HTS Oils Have Been Developed to Reduce Coking in
Engine Oil Systems
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 5
Experience with High Thermal Stability (HTS) Oils (MJO 254, MJO 291, BPTO
2197):
 Air BPTO 2197 (former EXXON 2197) was approved for CFM 56 in
Oct 2000 after service evaluation was conducted :
– Two CFM 56 -3 engines were disassembled and inspected
 All oil wetted parts were found very clean
 Aft sump oil supply and scavenge lines found with a light varnish
of coke deposit (no significant coke build-up)
 All inspected elastomeric and carbon seals were found in good
condition
 Oil analysis monitoring performed : no change in viscosity and
TAN
Oil Experience
HTS Oils Have Been Developed to Reduce Coking in
Engine Oil Systems
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 6
Background
• Since early 2001, a total of 25 cases of oil leaks have been reported on
CFM 56-5A and CFM 56-5B engines operating with MJO 291
 Oil leaks leading to D&Cs
 11 cases on CFM56-5B (affected engines had accumulated
approximately 3000 H with MJO 291 when the leaks occurred)
 14 cases on CFM56-5A (leaks occurred from 1400 H since using
MJO 291)
• Subsequent inspection revealed seals severely damaged with missing
material
• Affected seals are made of “fluorosilicone” material
• Same design since day 1 on all CFM 56 models (170 million hours of
experience)  No leaks reported in CFM56-7B fleet
SFH Gasket Seal - Oil leaks with MJO 291
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 7
Gasket between
SFH and MHE
SFH Gasket Seal - Oil leaks with MJO 291
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 8
Investigation Results
• Gasket seal were returned to CFMI for extensive investigation to assess seal
damage mechanism
• Specific laboratory testing conducted to evaluate swelling and aging behavior
of the fluorosilicone seal with MJO 291 versus other major oil brands
(including other HTS oils)
 At different temperatures up to 160°C
 On oil types : MJO 291, MJO 291+MJO 254, MJO254, JT2, EXXON
2380
 Results have shown that MJO 291 is more aggressive than other oil
types
SFH Gasket Seal - Oil leaks with MJO 291
Root Cause Identified to Be MJO 291 Associated
With Temperature
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 9
Investigation Results (cont’d)
• Laboratory testing also conducted to evaluate swelling and aging behavior of
the fluorocarbon seal with MJO 291 versus other major oil brands
 At different temperatures up to 160°C
 On oil types : MJO 291, MJO 291+MJO 254, MJO254, JT2, EXXON 2380
 Thermal cycling, and endurance tests have demonstrated a very good
behavior of this material versus MJO 291 characteristics and more
generally versus oil types (including HTS oils)
SFH Gasket Seal - Oil leaks with MJO 291
STATUS
New problem only experienced on engines operating with MJO 291 oil
CFMI & EXXON MOBIL are working the cause of the problem and
define corrective actions
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 10
Corrective Actions
• Containment Plan
 CFMI recommends that CFM 56 operators (all CFM 56 engines models)
using MJO 291 either consider a replacement of the gasket seal every
2,500 hours or discontinue the use of MJO 291 until the new gasket seal
is available
– FHL article issued in Aug 2001
– AOW issued 12 Dec 2001
• Final Fix
 Introduction of a new gasket seal design made of fluorocarbon material
on CFM 56 models has been validated
– In production, and field for CFM56-7B ===> Apr 2002
– New design fully interchangeable with current seal design
SFH Gasket Seal - Oil leaks with MJO 291
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 11
Summary
• HTS oils developed to reduce coking in the engine oil system
 MJO 291 validated on CFM 56 models in Oct 2000 after S.E completed
• Since early 2001 cases of Oil leaks on CFM56-5A /-5B Engines operated with
MJO 291
 SFH/MHE gasket seal (fluorosilicon) found damaged with missing material
 Extensive lab analysis confirmed MJO 291 as the root cause of the
problem
• Containment plan and corrective actions defined
 FHL article (08/01) and AOW (Dec 12, 2001) issued recommending for
operators using MJO 291 either to replace SFH/MHE gasket seal every
2500 H or discontinue use of MJO 291 pending new seal availability
 New gasket seal design (fluorocarbon material) in process to be
introduced
– In production and field on CFM56-7B by Apr 2002
SFH Gasket Seal - Oil leaks with MJO 291
High Temperature Oil Issues
February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 12
Other areas with risks of leaks
• CFMI has launched studies to list materials in contact with oil and assess sensitivity
with new oils
 C&A list parts with fluorosilicon material (seals, sealants) ==> Completed
 Engine list parts with other non metallic materials in contact or
susceptible to be spilled by the oil ===> Mar 2002
 Action plan to be defined following studies
– Technical risk of leak and subsequent corrective actions
 For fluorosilicon ===> Mid Feb 2002
 Other non-metallic parts ===> Jun 2002
Oil leaks with MJO 291: Other Issues
CFMI Still Working to Address the Problem and Define
Corrective Actions Depending on Technical Risk Analysis
High Temperature Oil Issues

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CFM High Temperature Oil Issues