Re: Continental 727 nearly belly-flops at O'Hare

From:         Robert Dorsett <rdd@cactus.org>
Date:         13 Jan 94 05:07:26 PST
References:   1 2 3
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>I was unclear in my orignal post.  If memory from Ground School serves, a 
>GPWS warning in IMC does require immediate action.  The last 727 Captain 
>I talked to said it is firewall thrust, and +15 pitch.  

Perhaps in that airline.  Considering the reliability (or lack thereof)
of the device, I'm surprised that it's advocated as a blind-response action,
and I've yet to meet a pilot (captain or otherwise) that would advocate 
reacting in that manner.  History's full of instances where "instantaneous"
responces precipitate more trouble than evaluating the situation.

This also harks back to the old thread on rec.aviation, "what is a warning?"
(specifically in regard to stall warning systems) A warning is just that: a 
warning.  It is not an instrument, and you can't fly by it.  You also can't
use the presence (or lack thereof) of that warning as an *absolute* indicator
that the threat exists (or does not exist).  T/CAS excepted. :-)


>This I find strange.  I believe the 727 is "certified" for flaps 30 and 
>flaps 40 landings (thus the heavy black line indicating that all weights at
>flaps 25 are above maximum structural landing weight - page L-3).  The 
>aircraft can also be landed flaps up- this is, however, an irregular 
>procedure, and the checklist involves dumping fuel and observing the max
>tire speed if possible.  I don't believe this is "certified", in the sense
>that it is acceptable to perform this type of landing on the line.  We would
>all agree that an ATC speed restriction should not be the cause of an Irregular
>Procedure.  I would also assume (although I'm not sure on this point), that
>part 121 would not permit an airliner to land under a configuration for which
>performance data could not be obtained.

The first rule of flight: what goes up, must come down... :-)

They certainly appeared to have screwed up; no argument there.  Just debating
some specifics.  And keep in mind that what appears in flight manuals is based
on (a) the AFM, (b) the chief pilot's personality and experience, and (c) what
the FAA wlil allow to form the final operations manual.  Thus, procedures and
limitations can vary widely among airlines.  And even within airlines.




---
Robert Dorsett
rdd@cactus.org
...cs.utexas.edu!cactus.org!rdd