Material fault

I would like to set the record straight regarding the DH Comet. It was a wonderful aircraft and not an engineering disaster

I would like to set the record straight regarding the DH Comet. Irrespective of what happened it was a wonderful aircraft. It was not an engineering disaster that Mr. Alec Collins would have us believe.

The reason for the failure was the specification of the aluminium used to clad the aircraft. Tests were carried out at Hatfield where a body of a Comet was installed in a large tank filled with water and the body of the aircraft subjected to many pressure cycles simulating the flight patterns of the aircraft. This went on for a considerable length of time before a failure occurred when it was discovered that this was caused by age hardening and cracking of the aluminium not the stressing.

It might be interesting to note that a similar failure occurred to a Spectre rocket outside pressure vessel made of the same material specification as the Comet. This casing was made, tested and put into stores. When it was taken out and retested it leaked and it was some time before it was realised that it was the material that had failed and not the design.

Roger Fletton, Keperra, Brisbane

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