NTSB ISSUES RECOMMENDATIONS ON GE REGIONAL JET ENGINES

[NTSB Press Releases <NTSBPressReleases@xxxxxxxx>]

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                      NTSB PRESS RELEASE
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National Transportation Safety Board
Washington, DC 20594

FOR IMMEDIATE RELEASE: March 5, 2008
SB-08-09

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NTSB ISSUES RECOMMENDATIONS ON GE REGIONAL JET ENGINES

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        The National Transportation Safety Board today issued 
recommendations to the Federal Aviation Administration to 
address a safety concern raised by two engine failures on 
Bombardier Canadair Regional Jet CRJ-200 aircraft.  A flaw 
during the manufacturing process for fan blades led to the 
two engine failures, and the Board wants procedures set up 
to remove these blades before another incident occurs.  A 
companion recommendation was sent to the Canadian 
government.

        In both instances - a July 27, 2006 engine failure on 
an Air Nostrum CRJ shortly after takeoff from Barcelona, 
Spain, and a May 24, 2007 engine failure on an Atlantic 
Southeast airlines CRJ while in cruise flight from Syracuse 
to Atlanta - a fan blade on a General Electric CF34-3B1 
turbofan engine fractured, causing a loud bang, severe 
vibration and in one case an engine fire.  Both flight crews 
declared emergencies and landed safely with no injuries.

        Examination of the blades showed that they failed due 
to a material defect introduced during the manufacturing 
process.  The fan blades were manufactured by Teleflex 
Aerospace Manufacturing Group, located in Mexico.  Teleflex 
has manufactured more than 28,000 of these blades.

        "We are issuing this recommendation because we 
consider the safety risk associated with this condition to 
be unacceptably high," NTSB Chairman Mark V. Rosenker said.

        The ASA fan blade failed after 4,717 cycles and 5,845 
hours, which is very early in a blade's service life, the 
Board said.  

        The Board issued six recommendations to the FAA, 
including that it require GE Aviation to define a reasonable 
maximum time frame below 4,717 cycles since new for these 
Teleflex fan blades and require that the blades be removed 
from service before that limit is exceeded, to require GE to 
include additional testing in the manufacturing process for 
those blades, and to require GE to make modifications in its 
CF34-1/-3 engine design to ensure that high engine 
vibrations (such as can happen when a fan blade fractures) 
will not cause the engine to catch fire.

        The Board also issued a recommendation to Transport 
Canada, that country's equivalent to the Department of 
Transportation, to require Bombardier to redesign the 
retention feature of the CRJ 100/-200 engine throttle 
gearbox to ensure that it can withstand the loads generated 
by a fan blade separation or similar event.

        Copies of the Board's recommendation letters may be 
accessed at the following links: 
http://www.ntsb.gov/Recs/letters/2008/A08_3.pdf 
 
http://www.ntsb.gov/Recs/letters/2008/A08_4_9.pdf 
 


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NTSB Press Contact:     Ted Lopatkiewicz
                                (202) 314-6100
                                lopatt@xxxxxxxx







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