The deHavilland Comet Disaster

The deHavilland Comet was the first commercial jet aircraft and ushered in the “Jet Age” on 2nd May 1952 by taking fare-paying passengers from London to Johannesburg. The aircraft featured several new technologies to allow it to operate economically and to enhance the flying experience for passengers. For several months the aircraft led the world by halving journey times and offering comfort levels which could not be matched on other piston-engined aircraft. However, two accidents in 1954 grounded the Comet fleet and the subsequent investigation has ensured that the deHavilland Comet disaster remains a notorious example of metal fatigue failure.

This high-profile incident encouraged much work in the field of fatigue, and has led to a much better understanding of the science of fatigue and the use of fracture mechanics to evaluate the life of components and structures. In fact, with modern understanding of metal fatigue, it is unlikely that the deHavilland engineers would have made the same design choices they did in the 1950s. So, knowing that our understanding of fatigue has evolved by leaps and bounds since the 1950s, why not use modern analysis methods to see if we would do anything differently today?

Paul Withey is the Professor of Casting at the University of Birmingham School of Metallurgy. Before his professorial role in academia, Paul worked at Rolls Royce for more than 20 years, culminating in his position as the Engineering Associate Fellow in Casting Technology. He now leads a lab looking at nickel-based superalloys and their growth.

I recently invited Paul to give a public lecture on the Comet disaster at the University of Bristol. Paul’s expertise in metal casting and fatigue means that he has been a guest on many documentaries on the deHavilland Comet disaster. The talk embedded below provides a fascinating account of the history of the Comet aircraft—from concept to entry into service. It then reviews the accident investigation at the Royal Aicraft Establishment in Farnborough, and uses modern fatigue analysis to propose a likely chain of events that led to the aircraft’s failure. Spoiler alert: No, it wasn’t the square windows…