Re: Boeing fuse pin revisited

From: (Greg Wright)
Organization: Boeing
Date:         08 Jul 93 01:28:00 PDT
References:   1
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In article <airliners.1993.490@ohare.Chicago.COM> (Robert Dorsett) writes:
>It does contain an interesting note, though, that Airbus apparently doesn't
>believe in "break-away" engines (the fuse pins installed on Boeing airplanes
>are there to permit the engine to shear away following substantial engine
>vibration, on the theory that it's better to drop an engine than risk damage
>to the airframe or wing).  "If an Airbus crash-lands, the plane can even skid
>on its engines without their falling off."

The main reason for the "Break-Away" engines was to keep the engines from
rupturing the fuel cells in the wing in the event of a crash landing.

>An issue of Aviation Week & Space Technology reported earlier this year that
>Boeing had found the problem was that Boeing had underestimated shear forces
>in one part of the assembly by 1000% or so.

It wasn't really underestimated, more like we found 'hidden' forces. In a
new FE analysis of the part on a new generation of computers it was found
that there existed very small areas of very high forces.  In the past it
was to computationally intensive to find these.

 ________Greg Wright________    OS2 2.1!!!!     High Lift Development 
| |   Falcon 3.0      747/767 Aerodynamics 
|    |                                           
|__uunet!bcstec!gregory_____|      NOT A BOEING SPOKESPERSON.