- Darling, Kev.
De Havilland Comet.
North Branch, MN: Specialty Press, 2001.
ISBN 978-1-58007-036-2.
-
If the
Boeing 377
was the epitome and eventual sunset of the piston powered airliner,
the
De Havilland Comet
was the dawn, or perhaps the false dawn, of the jet age. As World War II
was winding down, the British Government convened a commission to explore
how the advances in aviation during the war could be translated into
commercial aircraft in the postwar era, and how the British aviation
industry could transition from military production to a leadership position
in postwar aviation. Among the projects proposed, the most daring was
the “Type 4”, which eventually became the De Havilland Comet.
Powered by British-invented turbojet engines, it would be a swept-wing,
four engine aircraft with a cruising speed in excess of 500 miles per
hour and a stage length of 1500 miles. Despite these daunting technological
leaps, the British aviation industry rose to the challenge, and in July 1949, the
prototype De Havilland Comet took to the air. After extensive
testing, the Comet entered revenue service in May 1952, the first
commercial jet-powered passenger service. Surely the jet age was
dawning, and Britannia would rule it.
And then disaster struck. First, three aircraft were lost due to the
Comet's tetchy handling qualities and cockpit crews' unfamiliarity
with the need to maintain speed in takeoff and landing with swept-wing
aircraft. Another Comet was lost with all on board flying into a
tropical storm in India. Analysis of the wreckage indicated that
metal fatigue cracks at the corners of the square windows may have
contributed to the structural failures, but this was not considered
the definitive cause of the crash and Comets were permitted to
continue to fly. Next, a Comet departed Rome and disintegrated in
mid-air above the island of Elba, killing all on board. BOAC (the
operator of the Comet in question) grounded their fleet voluntarily
pending an investigation, but then reinstated flights 10 weeks later,
as no probable cause had been determined for the earlier crashes.
Just three days later, another BOAC aircraft, also departing Rome,
disintegrated in the air near Naples, with no survivors. The British
Civil Aviation Authority withdrew the Permit to Fly for the Comet,
grounding all of the aircraft in operation.
Assiduous investigation determined that the flaw in the Comet had nothing
to do with its breakthrough jet propulsion, or the performance it
permitted, but rather structural failure due to metal fatigue, which
started at the aerial covers at the top of the fuselage, then disastrously
propagated to cracks originating at the square corners of the windows
in the passenger cabin. Reinforcement of the weak points of the fuselage and
replacement of the square windows with oval ones completely solved this problem,
but only after precious time had been lost and, with it, the Comet's chance
to define the jet age.
The subsequent Comets were a great success. The Comet 2 served with distinction with
the Royal Air Force in a variety of capacities, and the Comet 4 became the
flagship of numerous airlines around the globe.
On October 4th, 1958, a Comet 4 inaugurated transatlantic jet passenger
service, but just 22 days before the entry into service of the
Boeing 707. The
707, with much greater passenger capacity (I remember the first time
I saw one—I drew in my breath and said “It's so
big”—the 747 actually had less impact on me than
the 707 compared to earlier prop airliners) rapidly supplanted the
Comet on high traffic city pairs.
But the Comet lived on. In the aftermarket, it was the jet fleet leader
of numerous airlines, and the flagship of British airtour operator
Dan-Air.
The Comet 4 was the basis for the
Nimrod
marine patrol aircraft, which has served with the Royal Air Force since 1971 and
remains in service today. With lifetime extensions, it is entirely possible
that Nimrod aircraft will remain on patrol a century after its progenitor,
the Comet, first took to the air.
This thorough, well-written, and lavishly illustrated (8 pages in
colour) book provides comprehensive coverage of the Comet and Nimrod
programmes, from concept through development, test, entry into
service, tragedy, recovery, and eventual success (short-lived
for the Comet 4, continuing for its Nimrod offspring).
October 2008 