The British Comet

After World War II, commercial aviation inter­ests in England conceded that the state of British aircraft technology and production was woefully behind that of the United States. The British, by necessity, had concentrated their efforts on fighter aircraft during the war, while the United States had been able to pursue transport devel­opment as well. The British concluded that they could never catch up with the Americans in exist­ing technology, but they saw a chance at leveling the competitive playing field with the United States by using the conventional turbojet in a new series of passenger transports.

In 1949, the De Havilland Comet began flight-testing with a design expectation of speeds of 480 miles per hour at flight levels of 35,000 feet. (See Figure 19-4.) While pressurized aircraft had been flying since the late 1930s, no airliner had faced the stresses that would be imposed at this projected altitude. The De Havilland Comet completed testing and entered into service on British Overseas Airways Corporation (BOAC) in May 1952, to the thrill and applause of the world. The first turbojet airliner halved flight times over BOAC’s world routes. To the surprise of many, the Comet made money even though

its operating costs were three times that of the DC-6, even charging regular fares. The differ­ence was that the Comet flew virtually full on all flights, proving that high-density seating was commercially feasible, at least on the vibration- free Comet. Next, Air France inaugurated jet ser­vice on some of its routes with the Comet. In the United States, it was still DC-7 and Superconstel­lation piston engine service.

The Comet had three serious accidents in 1953. The third one involved the airplane com­ing apart in the air, possibly due to a design flaw, but it had occurred in connection with suspected thunderstorm penetration and was written off to the expected result of thunderstorm force. A fourth accident on January 10, 1954 grounded all seven of the Comets. This fourth Comet was lost over the Mediterranean Sea as it climbed above

26,0 feet. Its wreckage fell into the sea and was not immediately available for study. A com­mission formed in England to study the accidents came up with some 50 fixes to be incorporated into the Comet fleet. These adjustments were made and the Comets resumed service.

The wreckage of the Mediterranean crash was recovered and taken to the Civil Aviation Investigation Branch in England for analysis. As

the investigation was proceeding, another Comet disappeared on April 8, 1954 on a flight from Rome to Cairo as it climbed to 35,000 feet. The fleet was again grounded and an all-out investi­gation was ordered to resolve the cause. It was fully appreciated that the future and reputation of the English aircraft production industry was now at risk, as was the entire future of commercial jet transportation.

The Royal Aircraft Establishment at Farn – borough, headquarters for British aeronautical research, was given the task of solving the mys­tery of the Comets’ crashes. A test procedure was contrived to expose the fuselage to a lifetime of pressurization and depressurization cycles, but at a rate 40 times faster than would normally occur. On June 24, 1954, the Comet’s fuselage failed, developing a structural crack at the corner of one of the square windows, and expanding away down the fuselage. This indicated that the Comets likely had exploded, not unlike a bomb, due to the interior pressure of the aircraft. In August 1954, the last section of the doomed Rome to Cairo Comet was recovered. The investigators’ conclu­sion of the cause of the crash was confirmed as the Comet’s fuselage disclosed an almost exact duplication of the test results. The Comet 1 never flew again. Two later iterations of the Comet never flew commercially. The official findings of the British government’s inquiry included that “more study both in design and by experiment” was needed to secure an economically safe life of the pressure cabin. These requirements were not met until 1958, at which time the Comet 4 made the first transatlantic jet commercial flight, on October 4, 1958. By then, the British advantage had been lost, and the United States aircraft pro­duction community was just getting started.