Supersonic passenger plane

The invention: 

The first commercial airliner that flies passengers at
speeds in excess of the speed of sound.


The people behind the invention:

Sir Archibald Russell (1904- ), a designer with the British
Aircraft Corporation
Pierre Satre (1909- ), technical director at Sud-Aviation
Julian Amery (1919- ), British minister of aviation, 1962-1964
Geoffroy de Cource (1912- ), French minister of aviation,
1962
William T. Coleman, Jr. (1920- ), U.S. secretary of
transportation, 1975-1977




Birth of Supersonic Transportations

On January 21, 1976, the Anglo-French Concorde became the
world’s first supersonic airliner to carry passengers on scheduled
commercial flights. British Airways flew a Concorde from London’s
Heathrow Airport to the Persian Gulf emirate of Bahrain in
three hours and thirty-eight minutes. At about the same time, Air
France flew a Concorde from Paris’s Charles de Gaulle Airport to
Rio de Janeiro, Brazil, in seven hours and twenty-five minutes.
The Concordes’ cruising speeds were about twice the speed of
sound, or 1,350 miles per hour. On May 24, 1976, the United States
and Europe became linked for the first time with commercial supersonic
air transportation. British Airways inaugurated flights
between Dulles International Airport in Washington, D.C., and
Heathrow Airport. Likewise, Air France inaugurated flights between
Dulles International Airport and Charles de Gaulle Airport.
The London-Washington, D.C., flight was flown in an unprecedented
time of three hours and forty minutes. The Paris-
Washington, D.C., flight was flown in a time of three hours and
fifty-five minutes.


The Decision to Build the SST

Events leading to the development and production of the Anglo-
French Concorde went back almost twenty years and included approximately
$3 billion in investment costs. Issues surrounding the
development and final production of the supersonic transport (SST)
were extremely complex and at times highly emotional. The concept
of developing an SST brought with it environmental concerns
and questions, safety issues both in the air and on the ground, political
intrigue of international proportions, and enormous economic
problems from costs of operations, research, and development.
In England, the decision to begin the SST project was made in October,
1956. Under the promotion of Morien Morgan with the Royal
Aircraft Establishment in Farnborough, England, it was decided at
the Aviation Ministry headquarters in London to begin development
of a supersonic aircraft. This decision was based on the intense competition
from the American Boeing 707 and Douglas DC-8 subsonic
jets going into commercial service. There was little point in developing
another subsonic plane; the alternative was to go above the speed
of sound. In November, 1956, at Farnborough, the first meeting of the
Supersonic Transport Aircraft Committee, known as STAC, was held.
Members of the STAC proposed that development costs would be
in the range of $165 million to $260 million, depending on the range,
speed, and payload of the chosen SST. The committee also projected
that by 1970, there would be a world market for at least 150 to 500 supersonic
planes. Estimates were that the supersonic plane would recover
its entire research and development cost through thirty sales.
The British, in order to continue development of an SST, needed a European
partner as a way of sharing the costs and preempting objections
to proposed funding by England’s Treasury.
In 1960, the British government gave the newly organized British
Aircraft Corporation (BAC) $1 million for an SST feasibility study.
Sir Archibald Russell, BAC’s chief supersonic designer, visited Pierre
Satre, the technical director at the French firm of Sud-Aviation.
Satre’s suggestion was to evolve an SST from Sud-Aviation’s highly
successful subsonic Caravelle transport. By September, 1962, an
agreement was reached by Sud and BAC design teams on a new
SST, the Super Caravelle.
There was a bitter battle over the choice of engines with two British
engine firms, Bristol-Siddeley and Rolls-Royce, as contenders.
Sir Arnold Hall, the managing director of Bristol-Siddeley, in collaboration
with the French aero-engine company SNECMA, was eventually
awarded the contract for the engines. The engine chosen was
a “civilianized” version of the Olympus, which Bristol had been developing
for the multirole TRS-2 combat plane.

The Concorde Consortium

On November 29, 1962, the Concorde Consortium was created
by an agreement between England and the French Republic, signed
by Ministers of Aviation Julian Amery and Geoffroy de Cource
(1912- ). The first Concorde, Model 001, rolled out from Sud-
Aviation’s St. Martin-du-Touch assembly plant on December 11,
1968. The second, Model 002, was completed at the British Aircraft
Corporation a few months later. Eight years later, on January 21,
1976, the Concorde became the world’s first supersonic airliner to
carry passengers on scheduled commercial flights.
Development of the SST did not come easily for the Anglo-
French consortium. The nature of supersonic flight created numerous
problems and uncertainties not present for subsonic flight. The
SST traveled faster than the speed of sound. Sound travels at 760
miles per hour at sea level at a temperature of 59 degrees Fahrenheit.
This speed drops to about 660 miles per hour at sixty-five thousand
feet, cruising altitude for the SST, where the air temperature
drops to 70 degrees below zero.
The Concorde was designed to fly at a maximum of 1,450 miles
per hour. The European designers could use an aluminum alloy
construction and stay below the critical skin-friction temperatures
that required other airframe alloys, such as titanium. The Concorde
was designed with a slender curved wing surface. The design incorporated
widely separated engine nacelles, each housing two Olympus
593 jet engines. The Concorde was also designed with a “droop
snoot,” providing three positions: the supersonic configuration, a
heat-visor retracted position for subsonic flight, and a nose-lowered
position for landing patterns.


Impact

Early SST designers were faced with questions such as the intensity
and ionization effect of cosmic rays at flight altitudes of sixty to
seventy thousand feet. The “cascade effect” concerned the intensification
of cosmic radiation when particles from outer space struck a
metallic cover. Scientists looked for ways to shield passengers from
this hazard inside the aluminum or titanium shell of an SST flying
high above the protective blanket of the troposphere. Experts questioned
whether the risk of being struck by meteorites was any
greater for the SST than for subsonic jets and looked for evidence on
wind shear of jet streams in the stratosphere.
Other questions concerned the strength and frequency of clear air
turbulence above forty-five thousand feet, whether the higher ozone
content of the air at SST cruise altitude would affect the materials of
the aircraft, whether SST flights would upset or destroy the protective
nature of the earth’s ozone layer, the effect of aerodynamic heating
on material strength, and the tolerable strength of sonic booms
over populated areas. These and other questions consumed the designers
and researchers involved in developing the Concorde.
Through design research and flight tests, many of the questions
were resolved or realized to be less significant than anticipated. Several
issues did develop into environmental, economic, and international
issues. In late 1975, the British and French governments requested
permission to use the Concorde at New York’s John F.
Kennedy International Airport and at Dulles International Airport
for scheduled flights between the United States and Europe. In December,
1975, as a result of strong opposition from anti-Concorde
environmental groups, the U.S. House of Representatives approved
a six-month ban on SSTs coming into the United States so that the
impact of flights could be studied. Secretary of TransportationWilliam
T. Coleman, Jr., held hearings to prepare for a decision by February
5, 1976, as to whether to allow the Concorde into U.S. airspace.
The British and French, if denied landing rights, threatened
to take the United States to an international court, claiming that
treaties had been violated.
The treaties in question were the Chicago Convention and Bermuda
agreements of February 11, 1946, and March 27, 1946. These
treaties prohibited the United States from banning aircraft that both
France and Great Britain had certified to be safe. The Environmental
Defense Fund contended that the United States had the right to ban
SST aircraft on environmental grounds.
Under pressure from both sides, Coleman decided to allow limited
Concorde service at Dulles and John F. Kennedy airports for a
sixteen-month trial period. Service into John F. Kennedy Airport,
however, was delayed by a ban by the Port Authority of New York
and New Jersey until a pending suit was pursued by the airlines.
During the test period, detailed records were to be kept on the
Concorde’s noise levels, vibration, and engine emission levels. Other
provisions included that the plane would not fly at supersonic
speeds over the continental United States; that all flights could be
cancelled by the United States with four months notice, or immediately
if they proved harmful to the health and safety of Americans;
and that at the end of a year, four months of study would begin to
determine if the trial period should be extended.
The Concorde’s noise was one of the primary issues in determining
whether the plane should be allowed into U.S. airports. The Federal
Aviation Administration measured the effective perceived noise
in decibels. After three months of monitoring the Concorde’s departure
noise at 3.5 nautical miles was found to vary from 105 to 130
decibels. The Concorde’s approach noise at one nautical mile from
threshold varied from 115 to 130 decibels. These readings were approximately
equal to noise levels of other four-engine jets, such as
the Boeing 747, on landing but were twice as loud on takeoff.


The Economics of Operation

Another issue of significance was the economics of Concorde’s
operation and its tremendous investment costs. In 1956, early predictions
of Great Britain’s STAC were for a world market of 150 to
500 supersonic planes. In November, 1976, Great Britain’s Gerald
Kaufman and France’s Marcel Cavaille said that production of the
Concorde would not continue beyond the sixteen vehicles then contracted
for with BAC and Sud-Aviation. There was no demand by
U.S. airline corporations for the plane. Given that the planes could
not fly at supersonic speeds over populated areas because of the
sonic boom phenomenon, markets for the SST had to be separated
by at least three thousand miles, with flight paths over mostly water
or desert. Studies indicated that there were only twelve to fifteen
routes in the world for which the Concorde was suitable. The planes
were expensive, at a price of approximately $74 million each and
had a limited seating capacity of one hundred passengers. The
plane’s range was about four thousand miles.
These statistics compared to a Boeing 747 with a cost of $35 million,
seating capacity of 360, and a range of six thousand miles. In
addition, the International Air Transport Association negotiated
that the fares for the Concorde flights should be equivalent to current
first-class fares plus 20 percent. The marketing promotion for
the Anglo-French Concorde was thus limited to the elite business
traveler who considered speed over cost of transportation. Given
these factors, the recovery of research and development costs for
Great Britain and France would never occur.

See also : Airplane; Bullet train; Dirigible; Rocket; Stealth aircraft;
                 Supersonic transport





Further Reading