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From: fowler@uw-beaver (Rob Fowler)
Newsgroups: net.aviation
Subject: Re: Most beautiful aircraft
Message-ID: <1395@uw-beaver>
Date: Tue, 16-Jul-85 15:49:32 EDT
Article-I.D.: uw-beave.1395
Posted: Tue Jul 16 15:49:32 1985
Date-Received: Fri, 19-Jul-85 01:33:20 EDT
References: <2857@decwrl.UUCP> <808@ihnp4.UUCP> <693@dataio.UUCP> <866@ccice5.UUCP> <1320@drux3.UUCP>
Reply-To: fowler@uw-beaver.UUCP (Rob fowler)
Organization: U of Washington Computer Science
Lines: 49

Speaking of  taking commercial aircraft to their limits, the following
was related to me by a Boeing engineer while we were on a DC10.  I started
the conversation by noting that as we became airborne that the fuselage
over the wing flexed to the point that it pinched my arm between the
armrest and the cabin wall.  That started the war stories.

He started with stating that Douglas builds flexible airframes compared to
Boeing products.  He first informed me that the reason that they have those
curtains across the cabin in stretch DC8's is because the fuselage flexes a
lot and it wouldn't do to have passengers noticing that the tail is weaving
back and forth a couple of inches with respect to the front of the cabin.

Then came the Boeing anecdote.  One of the first 707's was on a
trans-Atlantic run.  The captain had gone back to the head to relieve
himself when the autopilot tried to commit suicide.  The plane went into a
shallow but increasingly steeper dive.  After quite a few seconds the captain
pulls his pants up and works his way hand over hand up to to cockpit to
discover the co-pilot trying to regain control from the autopilot. (Don't
ask me why this was difficult.  It's not my story.) Anyway, by the time they
had the controls again they had lost a lot of altitude and were still
diving.  In a desperate move they did a very high G pullout at very low
altitude.  Since this may have overstressed the airframe they made an
unscheduled stop in Iceland.  FAA and Boeing inspectors were flown out and
the passengers went on in another plane.  The inspection revealed that the
pullout had permanently bent the wings up, back, and twisted them.  The
inspectors decided, however, that it was still airworthy and Pan Am put it
back in service with minor repairs.

Over the next couple of years this plane started to exhibit much better fuel
efficiency than other 707's.  Pan Am told Boeing and the latter tried to
figure out why.  Calculations and wind tunnel simulations on bent and
twisted 707 wings revealed nothing.  They decided that they had to measure
the plane and planned to do so during its next  X million mile overhaul.
They set up a hanger in Seattle with lots of photogrammetric cameras and
other test equipment in anticipation of getting their hands on this wonder.
They never did.  This plane was the first plane hijacked in the Middle East
and was blown up on the runway at Cairo.  The engineers never did figure out
why that particlar aircraft was so efficient.

I have no independent information to either confirm or deny the
truth of this tale.  Anyone out there ever hear this one before?
Oh yeah, watch out for the window seats over the wings on DC10's.
It's either perversly amusing or mildly alarming to feel the
cabin wall moving in and out as the wings flap when you go through
heavy weather.

-- Rob Fowler  uw-beaver!fowler or fowler@washington.arpa