Footnote on the DH Comet

Date:         06 Oct 97 02:14:19 
From:         "Walter E. Shepherd" <shepherd@courier6mac.aerospam.org>
Organization: The Aerospace Corp.
References:   1
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If my hazy memory serves me right, there was another factor beyond metal
fatigue which was contributory to the series of Comet disasters which I have
not seen mentioned in the recent thread in this newsgroup. Maintenance...
ground crews used to unpressurised propeller driven (i.e., low altitude)
aircraft with not much of a future (i.e., the short life expectancies typical
of combat aircraft) would drill holes at the end of fatigue cracks to keep
them from propagating further rather than to take the time to replace a skin
panel. This was SOP for workers (and a whole industry) who had gained prior
experience and training during the hectic pace of the war years.

If my memory is correct, the early Comet fleet reached a point where it was
riddled with small cracks terminated with little round holes. Most were along
the window line at the high stress points of the fuselage... so there was in
effect a perforated line waiting for the right moment to unzip the upper half
of the fuselage from the lower half. That moment came for several of the early
Comets at a most inconvienient time and place.

I mention this recollection because I believe that the current generation of
aviation industry workers, trained under totally different circumstances,
might not have the perspective to understand how such disasters can arise. I
have seen sentiments here in this newsgroup laying the blame at the feet of
the designers, at the feet of the UK aviation industry... etc, etc. I think no
one need be chastised... the disaster was simply a lingering after effect of a
disaster filled war... a war that also brought about the  huge growth of the
aircraft industry. In the seeds of miracle, also lie the seeds of disaster.

--Walt Shepherd