Britain Built the World's First Jet Airliner. The Comet Tore Itself Apart, and Boeing Took the Jet Age.

On July 27, 1949, the de Havilland Comet made its first flight from Hatfield, the first pressurized jet airliner, and a broke, bombed-out Britain looked set to own the age of jet travel. Five years later two Comets broke apart in mid-air, the fleet was grounded for good, and the sharp-cornered cabin cutouts that caused it handed the future to Boeing.

The press had wandered off. After a couple of low hops down the runway at Hatfield Aerodrome in Hertfordshire, the reporters covering de Havilland's new machine assumed the show was over and went home. So on the evening of July 27, 1949, only the company's own people watched Chief Test Pilot John Cunningham, a wartime night-fighter ace nicknamed "Cat's Eyes," take the prototype de Havilland DH.106 Comet up for real. He climbed toward 8,000 feet, swept low over the runway in salute to his colleagues, and landed after 31 minutes. "The flight was entirely successful," he said. "She was very nice to handle." It was the 67th birthday of Sir Geoffrey de Havilland, the company's founder, and the first true jet airliner had been born on it.

The Comet was a revelation. Four Ghost turbojet engines buried in the wings, a highly pressurized cabin, nearly 500 mph at 40,000 feet. When BOAC opened the world's first jet passenger service on May 2, 1952, from London to Johannesburg, the Comet flew twice as fast and twice as high as any propeller airliner, in a cabin so smooth passengers stopped getting airsick. Postwar Britain, still rationing food and rebuilding its bombed cities, had stolen a march on the entire aviation world.

Then the cracks opened. On May 2, 1953, a Comet broke apart in a violent storm over Calcutta, killing 43, and was blamed on the weather. Eight months later, on January 10, 1954, BOAC Flight 781 had just lifted off from Rome and was climbing through 27,000 feet when the radio cut out mid-sentence. The plane tore itself apart over the Mediterranean near the island of Elba. Thirty-five dead, no distress call, no obvious cause. The fleet was grounded, given 60 modifications, and put back to work. Three months after that, on April 8, 1954, a Comet chartered to South African Airways broke up near Naples. Twenty-one more dead. This time the Comet was grounded for good.

The Royal Aircraft Establishment at Farnborough ran what is still one of the most painstaking crash investigations ever mounted. Salvage crews hauled wreckage off the Mediterranean seabed and engineers reassembled two-thirds of the Elba fuselage like a jigsaw. Then they took an entire Comet fuselage, sealed it inside a water tank, and pressurized and depressurized it thousands of times to simulate years of flights. It burst open after the equivalent of roughly 3,000 cycles, far short of the 10,000 the designers expected. The fatal crack had begun at a rivet hole in the corner of a sharp, almost-square cutout in the cabin roof, an opening for a navigation antenna. Every time the cabin pressurized, stress piled up at the corners, until the metal fatigued and the fuselage ripped open like a balloon.

There was a cruel twist. De Havilland had proof-tested a prototype cabin to twice the normal pressure, which inadvertently hardened the corners and hid the weakness. The production planes never got that treatment, so they fatigued at roughly 1,000 flights, a tenth of the design life. The Elba aircraft had made just 1,290 pressurized flights.

De Havilland redesigned the Comet with rounded windows, thicker skin, and a fail-safe structure, and the new Comet 4 inaugurated the first transatlantic jet service on October 4, 1958. But Boeing's 707, bigger and more economical, was already there, and the Douglas DC-8 followed. The Comet that should have owned the jet age became a footnote; BOAC retired its last one in 1965. The three fatal crashes killed 99 people.

The echo is everywhere you fly. Every pressurized airliner since has rounded cabin windows, because stress flows smoothly around a curve and piles up at a corner. The investigation made fatigue testing and fail-safe design mandatory, and the lessons de Havilland bought the hard way went straight into Boeing's jets. As the aviation writer D. D. Dempster put it in 1959, no aircraft has contributed more to safety in the jet age than the Comet. The lessons it taught the world live in every jet airliner flying today. The pioneer did not win the market. It taught everyone else how to.

Also on this day

1789: Congress establishes the Department of Foreign Affairs, the first federal agency under the new Constitution, renamed the Department of State two months later. (Office of the Historian)
1940: Bugs Bunny makes his official debut in the Warner Bros. short "A Wild Hare," the first cartoon to pair him with Elmer Fudd and fix the smart-aleck persona that lasted decades. (Wikipedia)
1953: After 158 meetings spread over two years and 17 days, generals sign the Korean War armistice at Panmunjom in 10 minutes with no handshake, and no peace treaty has ever followed. (National Archives)
1974: The House Judiciary Committee votes 27 to 11 to approve the first article of impeachment against Richard Nixon, for obstruction of justice; he would resign 13 days later. (American Presidency Project)
1996: A pipe bomb kills two and injures 111 at Centennial Olympic Park in Atlanta during the Summer Games; security guard Richard Jewell was hailed as a hero, then wrongly suspected, before Eric Rudolph was caught in 2003. (FBI)