Re: GE90 Engines

From:         chuanga@indirect.com (Andrew Chuang)
Organization: International Internet Association.
Date:         22 Jun 95 03:07:30 
References:   1 2
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In article <airliners.1995.843@ohare.chicago.com>,
Drakeal <drakeal@aol.com> wrote:
>
>GE's ambitious hollow composite fan blade program

P&W and R-R use hollowed titanium fan blade; GE's composite blade is not
hollow!

>was intended to
>put it leagues ahead of competitors Pratt & Whitney and Rolls-Royce in
>thrust/weight.

The GE90 is the heaviest engine among the three competitors.

>But it ran into snags when they tried to certify it with
>the FAA.  The agency gave them the choice of 1) 8-lb birdstrike test or 2)
>artifically separating a single blade at the root, whichever was tougher.
>GE chose (2).

Both bird-ingestion and blade-out tests are required for all the three
engines.  The only difference is that in GE's blade-out test the fan blade
was broken off in the flow path instead of at the root.

>
>To make a blade birdstrike-worthy, you have to beef up the root of the
>blade

I don't believe they are beefing up the root of the blade.  GE is fixing
the platform (an aluminum fixture in between the fan blades).

>But P&W's is certified, and GE's is not;

BTW, the failed bird-strike test is actually for the 92K GE90.  The 85K
GE90 was certified in February.  Even before the failed test, the
B777/GE90 combination was not expected to be certified until August.

--
  H Andrew Chuang   chuanga@iia2.org