Re: Jet Engine Containment/GE90

From: (MeyerTed)
Organization: America Online, Inc. (1-800-827-6364)
Date:         23 Aug 96 13:45:05 
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A while back, Steven Foister of GEC-Marconi Avionics posted some
observations about containment, along with the following:
<snip> "Anyway, I am sure that someone from GE will write in and refute
me...<snip>" Well, here it goes:

First, the GE90 does not have "a much heavier fan blade."  These
blades are made of composite materials and, although they are
dimensionally larger, are about the same weight or lighter than
those of our competitors.

Second, and more importantly, the implication that the engine has
still not completely passed the containment test is incorrect.  The
GE90 was fully certified by the FAA in February 1995.  There are
absolutely no temporary waivers or exemptions associated with the
FAA certification.  In addition, the engine has also been fully
certified by the European airworthiness authorities (JAA and CAA)
with no waivers or exemptions.

The FAA did allow GEAE to perform the containment test by releasing
the fan blade at the base of the airfoil (which is not "half way up
the blade"), rather than the dovetail.  This approval was granted
after GEAE successfully demonstrated that the composite fan blades
are "prime reliable," meaning that no mechanism could be found that
would cause the blade to fail below the base of the airfoil.

The GE90 has been in service on the 777 for nearly a year.  During
that time, the fleet has logged more than 20,000 engine flight hours
- approximately 15,000 of which have been in service with British
Airways -  with no in-flight operational disruptions and a dispatch
reliability rate of 99.95%.  Based on the data we have access to,
the GE90 is the most reliable engine on the 777.

Hope that is helpful to all here, but feel free to contact us with
additional questions.

Ted Meyer

GE Aircraft Engines