As Mike Ramsden has not posted here (yet), I'll pass on these:
Quote from sender of Mike's letter:
"You may have seen, or heard about, a "Secret History" programme on Channel 4 on 13th June. It was entitled "Comet Cover-up" and included interviews with John Cunningham, Ralph Hare, Mike Ramsden and John Wilson - all of whom had been invited to take part in a programme "to celebrate the 50th Anniversary of the Comet's entry to passenger service". The final production purported to show a sinister plot on the part of DH to get the Comet into service regardless of adequate testing.
"Mike Ramsden has written the following letter for as wide as possible circulation to put the record straight. It was sent to me via the DH Tech School Old Boys Association email list. I don't know how or where Mike Ramsden intends to get it published but I thought you all might be interested.
"Tony Fairbrother was told that the programme's producer was changed late on in production, which may account for the change in slant. I can't imagine those interviewed were aware how their comments were going to be used! Dick Bishop can't have been too pleased with what was virtually a character assassination of his father."
Mike's letter:
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18 June 2002
Comet Cover-Up
As one of the ex de Havilland people who appeared in the Secret History TV programme about the Comet 1 disasters (Channel 4, 13 June) I would like the truth to be known.
Disasters they were, as we shall not forget. But to accuse de
Havilland and its chief designer R. E. Bishop of avoiding fatigue tests is outrageous. "Secret letters" are cited in support of this allegation. Secret letters from whom, dated when, saying what exactly? Can we have copies? Fleeting glimpses of old files containing the word "fatigue", accompanied by doom-laden music and voice commentary, do not prove anything.
In 1952-53 we built two full-scale test sections of the Comet 1 fuselage including windows, and tested them in the Hatfield water tank. They were intended to prove singIe-overload bursting strength arid repeated-load fatigue strength.
Professional structural engineering opinion at the time was that fatigue strength could be demonstrated by "static" strength. Thus we pumped up one test section to twice normal working pressure (P). If it had failed at less than 2P, which it didn't, we would have been back to the drawing board. We believed we had demonstrated the Comet 1's fatigue and static strength.
Chief designer R.E. Bishop went further. He said "show me 2.5P". We did that too. He then ordered a fatigue test: 16,000 repeat loadings of 1.25P. That test, a world first, went beyond the call of airworthiness requirements. Bishop went even further and ordered the repeat-loading of individual windows to 2P. As an apprentice in the structural test department in 1949 I remember these tests personally. My job was to polish the windows each morning with "Ajax" to see whether any loss of thickness
from window-cleaning in airline service would affect the transparency's strength. Far-fetched, but a measure of Bishop's conscientiousness.
I explained all this in filmed interviews with the Channel 4 programme makers, Steve Ruggi and David Coward. Too technical and boring, perhaps. They edited it all out. But to state as fact that de Havilland refused to fatigue-rest the Comet 1 is just wilful untruthfulness. It makes you wonder how much you can believe of any Channel 4 documentary.
Yes, the Comet 1 windows failed catastrophically from fatigue. No
excuses. But there were reasons - reasons which were established and published by the inquiry and which advanced the science of structural design, inspection and testing.
The Comet 1 windows failed because the production window-cutout reinforcing plates were riveted - and very poorly riveted - instead of being glued (Reduxed) as in the test section. And the test section may have been toughened by the 2.5P load applied to it before the 16,000 x I 25P fatigue cycles. These were mistakes. But they were honest mistakes, made in the course of pioneering unknown structural territory, and they were exposed by a public inquiry.
Bishop accepted responsibility, even though a lesser man would have blamed the production or structures departments, or both. -
Engineers who try to do things which have never been done before will get some things wrong, but besmirching their reputations by representing their honest mistakes as conspiracies is just cheap.
The TV programme makers and editors concerned got much else wrong, too much to elaborate here and some of it ridiculous - for example, that the Comet 1's skin thickness was determined by the choice of de Havilland Ghost rather than Rolls-Royce Avon engines.
Incidentally, Principal films told me and the de Havilland colleagues
who appeared in the programme (and lent personal film, photos and documents) that it was to celebrate the 50th anniversary of jet transport. Was that an honest mistake?
J.M. (Mike) Ramsden