Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
NE-10-37
July 12, 2010
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) advises the
owners and operators of airplanes equipped with General Electric
Company (GE) CF6-80C2 series turbofan engines of the potential for
engine in-flight shutdowns (IFSDs). This SAIB applies to GE CF6-80C2
series engines controlled by a Full Authority Digital Electronic
Control (FADEC) in any airplane configuration, except Boeing 747 and
767 airplanes that have incorporated FADEC software version 8.2.R.
These engines are installed on Boeing 747, 767, Airbus A300, and
McDonnell Douglas MD-11 airplanes. At this time, the airworthiness
concern is not an unsafe condition that would warrant airworthiness
directive action under Title 14 of the Code of Federal Regulations (14
CFR) part 39.
Background
The potential engine IFSDs addressed by this SAIB are due to feedback
faults on both FADEC channels from the Fuel Metering Valve (FMV). A
single-channel FMV feedback fault is not annunciated to the crew and is
recorded only in the maintenance computer. The maintenance computer
overwrites the recorded fault every 64 engine cycles, so an
intermittent fault may go unnoticed if the maintenance computer is not
read while the fault is active and recorded. A dual-channel FMV
feedback fault will cause an uncommanded engine IFSD.
Recommendations
To prevent a single-channel intermittent fault from progressing to a
dual-channel fault and subsequent IFSD, it is recommended that the
maintenance computer be queried at more frequent intervals. The maximum
recommended maintenance computer review interval is every 1,000 flight
hours. If an FMV feedback fault message is found in the maintenance
computer, disposition the fault using the appropriate aircraft Fault
Isolation Manual (FIM). If no cause is found for the FMV fault, replace
the Hydromechanical Unit on the engine. For Boeing 767 applications,
see GE CF6-80C2 Service Bulletin No. CF6-80C2 S/B 73-0372 for
information on detecting FMV feedback faults and dispositioning the
hardware if a fault is found.
Additionally, FADEC software version 8.2.R is available for engines
installed on Boeing 747 and 767 applications. FADEC software version
8.2.R latches the FMV feedback fault and will prevent the maintenance
computer from automatically overwriting fault-related information. For
engines installed on Boeing 747 and 767 series airplanes, we recommend
installing FADEC software version 8.2.R or more recent version, as an
additional safety measure to prevent IFSDs due to dual-channel FMV
feedback faults. Once FADEC software version 8.2.R or more recent
version is installed, the reduced maintenance computer check interval
would no longer be necessary.
For Further Information Contact
Christopher J. Richards, Aerospace Engineer, 12 New England Executive
Park, Burlington, MA 01803; phone: (781) 238-7133; fax: (781) 238-7997;
e-mail: Christopher.J.Richards@faa.gov.
For Related Service Information Contact
GE Aviation Operations Center, telephone (513) 552-3272; or GE Aviation
Customer Web Center, on the Web at https://customer.geae.com.