Sunday, May 06, 2007

The Saga of the De Havilland Comet

News agencies reported thousands of people gathered at London Airport (now better known as Heathrow) on May 2nd 1952 to witness the first jet operated commercial flight.

At 3:12PM, the BOAC Comet registered G-ALYP took off for its first commercial flight. Carrying 36 passengers, its destination was Johannesburg with scheduled stops at Rome, Beirut, Khartoum, Entebbe and Livingstone. The total journey of nearly 7000 miles (11260 km) was scheduled to take 23h 40 minutes. Prop driven planes took twice that long.

BOAC was the first airline to operate jet equipment. The revolutionary Comet would forever change the way we travel. At first, BOAC was the only airline to operate the Comet. Air France, UAT, Canadian Pacific, British Commonwealth Pacific were next in line to operate the revolutionary machine. Pan Am and others were soon to join in as no other aircraft like the Comet was available; the Boeing 707 was still on the drawing boards.

Unfortunately, the future of the Comet was not bright. Its manufacturer and designer, de Havilland Aircraft, would pay the price for being first. They had pushed the envelope of aircraft design and performance, unfortunately the envelope pushed back. No one had ever built and flown a pressurized aircraft as large and with the capability to fly as high and fast as the Comet. She was literally flying in unchartered territory.

A series of accidents doomed the new plane. The first two crashes were blamed on pilot error, specifically not being aware of some characteristics of jet take off, and in the second accident in Karachi, Pakistan, perhaps the first noted case of jet lag. On the first anniversary of the first flight, BOAC Comet G-ALYV crashed in Calcutta. At first it was assumed to be due to flying through a strong storm, later events would show a more serious cause.

Comets were grounded as G-ALYP itself would be the 4th Comet to crash on January 10th 1954 after taking off from Rome-Ciampino airport. It suffered a mid-air explosion and plunged into the Mediterranean Sea near Elba. After a lengthy investigation of the recovered aircraft, Comets were allowed to return to the air with changes designed to hopefully correct the problems found.

On April 12th, 1954, just 16 days after being allowed in the air, BOAC Comet G-ALYY crashed in the bay of Naples, after its take off from Rome this time headed south to Cairo. Comet 1s were permanently grounded.

Testing would show that the last two accidents and likely the one in Calcutta were caused by metal fatigue. The science of metallurgy was very new. De Havilland had tested the frame thoroughly they thought. They tested a test frame to pressures twice their normal levels with no problem. That should have been sufficient. But metal had not coughed up one of its secrets, pressure that high actually helps bond and parts and changes the structure of the metal. No one knew that at the time. An official inquiry placed no blame. The Comet experience had taught aircraft manufacturers a lot, but at a high price.

We have the Comet to thank for the mighty and safe machines that take us around the world in modest comfort (unless you pay out the nose and go first class and then go in style) shrinking our globe and uniting the world.

Beautiful machine too.

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