Re: Lufthansa crash in Warsaw - Preliminary findings

From:         spagiola@FRI-nxt-Pagiola.Stanford.EDU (Stefano Pagiola)
Organization: Stanford University
Date:         19 Oct 93 12:49:41 PDT
References:   1
Followups:    1
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Robert Ashcroft writes
> {A320 crash in Poland)
> > Ok. I thought you know, what problems can arise, when aquaplaning
> > occurs. The thrust reversal only works, when the wheels are
> > turning !!  This is provided for security reasons ! The thrust
> > reversal should only available on the ground.  They commission
> > said, aquaplaning can cause that.
> That's incredible, if it is true.  Is this a feature of all
> thrust-reversing systems, or something that was built into the
> A320 fly-by-wire system? And if this is unique to the fly-by-wire
> system, does it take the blame for the crash?

I'm not sure about thrust-reversing, but I remember Piedmont lost a  
737 at Charlotte some time ago when some combination of aquaplaning  
and floating in ground effect meant spoilers could not be deployed  
because releasing them requires the mainwheels to be firmly on the  
ground and to have begun turning.  Just as it makes sense (most of  
the time) to prevent spoiler deployment in flight, it probably would  
make sense to have similar safeguards to prevent thrust reverser  
deployment in flight.  Can anyone confirm whether/how its actually  

Stefano Pagiola
Food Research Institute, Stanford University (NeXTMail encouraged) (NeXTMail encouraged)