The Fall of the Comet
Accidents started to plague the Comet in 1953. The early incidents involved failures to takeoff. It was determined the airplane was not generating enough lift in low speed, heavy weight conditions. Modifications were made to improve the low speed performance of the aircraft. These early incidents did not reduce the public enthusiasm about the Comet.
In 1954, two accidents changed the way the Comet was perceived. In January of that year a plane climbing out of Rome to a cruising altitude of 36,000 feet disintegrated between 26,000 and cruise altitude. The Comets were grounded and modifications were made, even though De Havilland did not know the exact cause of the accident. Unfortunately, just two weeks after the Comets resumed flying another plane came apart climbing to 36,000 feet.
To find the cause of the accidents, De Havilland built a giant tank and submersed an entire Comet. In the tank the aircraft cabin was pressurized and the plane was subjected to the movement and pressure changes of thousands of hours of flight. It was discovered that stress points were forming at the corners of the square windows of the original Comet. The stress points would lead to failure in the integrity of the aircraft and total failure of the aircraft in flight.
It took four years for De Havilland to re-engineer the structure of the Comet including the installation of round windows. The Comet's reputation was destroyed by effects and forces the plane encountered flying at speeds and altitudes that were a new frontier for aviation. By the time the improved Comet rolled out, the new Boeing 707 was in service and was to become the airliner of the new jet age.