B S D Chapman mail-at-benchapman-dot-co-dot-uk wrote in message ...
pacplyer wrote:

As well, the lack of a robust wheel-well area that could not allow for
tire fragments at 200mph seems like another pioneering shortfall just
like square windows on a pressurized fuselage. My comments were not
meant to denigrate either spectacular flying machine, just to point
out that these were the first of their kind out of the gate, and that
without good factory/national support the continued operation of a
sole example seems risky at best. (but I too would like to see it fly
again.)

Sorry for missing this earlier...

Common misconception. The square windows were not the point of failure on
the Comet I, they just happened to change the design as a result of
learning more about metal fatigue.

The actual point of failure was around one of the nav arials (VOR I think).


No, the point of fuselage failure was the large picture windows. That
is what brought down the first Comets. It doesn't matter where the
crack starts from. If you've got big square windows with sharp
corners in them on an expanding and contracting surface, you've got a
time bomb ticking. With small round windows (which the 707 by no
small accident adopted) the Comet airframes might have stayed intact.
True, the hole that the avionics aerial was mounted against was the
beginning of the stress crack that ran around to the windows in at
least one Comet I accident, but big cracks happen all the time on big
iron today and the airframes don't just fall out of the sky because a
crack started somewhere. Another example of this is the "stop drill"
hole used a little ahead of the end of a crack (an approved repair
method on some skins.) The round shape will relieve stress and stop
the crack from progressing. Licensed mechanics today know you can't
install a rotating beacon, a nav antenna, or a window for that matter,
without producing a gradual radius in the corners of the hole in the
skin. This becomes more important on pressurized structures.

pacplyer