Do you need to get from London to New York in a hurry? No
problem! Just hop onboard the world's fastest passenger airplane,
the Concorde, and you will be there in less than four
hours! How can you cross the Atlantic in such a short amount
of time? Simple: The Concorde travels faster than sound!
Photo courtesy British Airways Concorde supersonic passenger jets
In this edition of HowStuffWorks,
we will show you how this amazing vehicle works.
A Little History In 1962, the British and
French governments signed an agreement to develop a
supersonic transport aircraft (SST). The plane was
built jointly by British Aerospace (BAe) and Aerospatiale. Two
prototypes were built, and the first flight took place in
1969. A total of 20 Concordes were made, of which 13 are still
in service. The planes are flown by British Airways and Air
France. The 30th anniversary of the Concorde took place on
March 2, 1999. Ten of the Concordes have flown more than
920,000 hours.
The American and Soviet governments also had plans to build
an SST. In the United States, Boeing contracted to build a
prototype. However, the program was killed in 1971 after a
federal report stated that it would be too costly to continue.
The Russians built an SST similar in design to the Concorde,
called the Tupolev Tu -144, nicknamed the "Konkordski."
Photo courtesy NASA The Russian Tu -144LL landing
In 1973, a Tu -144 crashed at the Paris Air Show. The crash
was probably caused by pilot error. However, the Tu -144's use
for passenger flights was suspended (see Nova:
Supersonic Spies for details on the Tu -144 and events
surrounding the crash). The Tu -144 was modified and used for
air-mail
service. Several Tu -144s have been donated to museums,
and one is being used now in a joint aeronautic project
between the Russian government and NASA for supersonic-flight
research.
Photo courtesy British Airways A flight engineer installs a Kevlar liner to
a Concorde's fuel tank for its return to
flight.
Today, the Concorde
is the only SST in commercial service. However, the Concorde
has had its share of problems. On July 25, 2000, an Air
France Concorde flight en route from Paris to New York
crashed just moments after takeoff, killing all
passengers and crew as well as several people on the ground.
Investigations into the crash have centered on a loose strip
of metal that was lying on the runway. It is believed that the
metal caused one of the Concorde's tires to blow
out. Debris from the tire was sucked into the engine and/or
fuel tank and caused a fire on the portside (left) engine,
yielding 200-foot-long flames. The aircraft stalled, tumbled,
and crashed on a hotel in nearby Gonesse. Both British Airways
and Air France immediately grounded their Concorde
fleets.
The Concordes are undergoing modifications. These
modifications include installing Kevlar linings to the fuel
tanks, to prevent them from rupturing in the event that the
wing is punctured, and strengthening the wiring in the
undercarriage. The Concordes are projected to be back in
commercial service in September 2001.
Now that we know some of the history of the Concorde and
other SSTs, let's look at the details of these aircraft.
The Concorde vs. Other Passenger Jets The
Concorde flies faster and higher than most commercial jets.
For example, a Boeing 747 aircraft cruises at about 560 mph
(901 kph, or Mach 0.84) at an altitude of 35,000 ft (10,675
m). In contrast, the Concorde cruises at 1,350 mph (2,172 kph,
or Mach 2) at an altitude of 60,000 ft (18,300
m). Because the Concorde travels faster than the speed of
sound and almost twice as high as other commercial jets, it
has several features that set it apart from other aircraft:
Structural diagram of a Concorde Move your mouse
over the color options to see where each component is located
on the Concorde.
Let's look at these features in detail.
Streamlined Design As any aircraft
approaches the speed of sound (1100 ft/s, 343 m/s), the air
pressure builds up in front of the aircraft, forming a
"wall" of air. To punch through that wall of air, planes must
be streamlined. To streamline the Concorde, the following
designs have been implented:
Needle-like fuselage
Swept-back delta wing
Moveable nose
Vertical tail design
The fuselage
(body) of the Concorde is only 9.5 ft (2.7 m) wide (for
comparison, a 747 is 20 ft (6.1 m) wide). The length of the
Concorde is about 202 ft (61.7 m), just slightly shorter than
a 747. The long, narrow shape of the Concorde reduces the drag on
the plane as it moves through the air.
Photo courtesy British Airways Drawing of the Concorde in flight: Note the
wide, triangular wing structure and lack of horizontal
tail.
Photo courtesy British Airways A Boeing 747 in flight: Note the thin,
rectangular wing structure and horizontal stabilizer on
the tail.
The wing of the Concorde is thin, swept back and
triangular, whereas a 747's wing is swept back but
rectangular. Also, there is no space between the fuselage and
the wing of the Concorde as there is in the 747. The
Concorde's wing is called a delta-wing design and does
the following:
Reduces drag by being thin and swept back (55 degrees
with the fuselage)
Provides sufficient lift
for takeoff and landing at subsonic speeds
Provides stability in flight so that no horizontal
stabilizers are needed on the tail
The Concorde has
a longer, needle-shaped nose compared to most commercial jets.
The nose helps penetrate the air, and can be tilted down upon
takeoff and landing (13 degrees) so that the pilots can see
the runway. (Delta-winged aircraft have a steeper angle of
attack during takeoff and landing than other types of
aircraft.) Also, the Concorde's nose has a visor to
protect the windshield when flying at supersonic speeds.
As mentioned above, because the delta wing provides
stability to the aircraft, the Concorde does not require a
horizontal stabilizer on the tail like most other aircraft.
These designs in the body and wings of the aircraft allow
it to move easily through the air at high speed.
Engines The engines on the Concorde provide
the thrust
necessary for takeoff, cruising and landing. The Concorde has
four Rolls Royce/Snecma Olympus 593 turbo jet
engines. Each engine generates 18.7 tons (180 kN)
of thrust. Together, the four engines burn 6,771
gallons (25,629 liters) of fuel per hour.
The location and type of engines on the Concorde's are
different from on other jets.
Photo courtesy British Airways Concorde in flight: Note that the engines are
attached directly underneath the wing without
struts.
Photo courtesy British Airways Airbus 320 in-flight: Note that the engines
are attached underneath the wing with struts.
The Concorde's engines are attached directly to the
underside of the wing without engine struts. This design
reduces air turbulence and makes for a more stable engine. At
supersonic speeds, engine struts would be overstressed and
likely to break.
The Concorde's engines use afterburners
to gain additional thrust to reach supersonic speeds.
Afterburners mix additional fuel with the exhaust gases from
the primary combustion chamber and burn it to get more thrust.
Afterburners are typically used on supersonic military jets.
Other Special Components There are several
components that enable and support the speed and power
achieved by the Concorde.
Fuel Tanks The Concorde
has 17 fuel tanks that can hold a total of 31,569
gallons (119,500 liters) of kerosene
fuel. The main tanks are located in each wing (five on
each side) and fuselage (four).
The Concorde also has three auxiliary or trim fuel
tanks (two in front and one in the tail). Here is what the
trim tanks are used for:
As the Concorde reaches supersonic speeds, its
aerodynamic center of lift shifts backward.
This shift drives the nose of the aircraft downward.
To maintain balance, fuel is pumped backward into the
trim tanks.
The redistribution of fuel balances the aircraft by
making its center of gravity match the center of lift.
When the plane slows down, the center of lift shifts
forward.
Fuel is then pumped forward into the trim tanks to
compensate.
So, unlike other jets, the Concorde uses
fuel not only for the engines, but also for aerodynamic
stability.
High-reflectivity
Paint Because the Concorde moves faster than sound,
the air pressure and friction (collision with air molecules)
really heat up the plane. The temperature of the
aircraft's skin varies from 261 degrees Fahrenheit (127
degrees Celsius) at the nose to 196 F (91 C) at the tail. The
walls of the cabin are warm to the touch. To help reflect and
radiate this heat, the Concorde has a high-reflectivity white
paint that is about twice as reflective as the white
paint on other jets.
The heat encountered by the Concorde causes the airframe to
expand 7 inches (17.8 cm) in flight. To minimize the
stress on the aircraft, the Concorde is made of a special
aluminum alloy (AU2GN) that is
lightweight and more heat-tolerant than titanium.
Now that we have seen the technical features that make the
Concorde special, let's look at a typical flight from London
to New York.
A Trip on the Concorde
Photo courtesy British Airways The Concorde's cabin
You arrive at London
Heathrow airport
for the 10:30 a.m. flight, check in, check your luggage and
wait in the Concorde Lounge of British Airways. When it comes
time, you board the airplane. The Concorde can hold 100
passengers, with two seats on each side of the aisle. The crew
consists of the pilot, co-pilot, flight engineer and six cabin
crew members. You sit in your seat and await the takeoff.
As the plane taxis to the runway and begins takeoff; its
nose is down. The engines fire with 38,000 pounds of thrust,
and you go from zero to 225 mph (362 kph) in just 30 seconds
-- so fast that you are pushed back into your seat by the
acceleration. The noise of the engines roars through the
cabin. You quickly reach your cruising altitude (11.3 mi/18.3
km) and pass the sound barrier. The plane's nose is now
up. A sign inside the cabin displays the Mach number
continuously. As you look out the window, you can see the
Earth's curvature. You are at the edge of space between the
stratosphere and the ionosphere -- you can see the colors of
the stratosphere!
Photo courtesy British Airways A typical in-flight meal on the
Concorde
While you are in flight, you can enjoy a gourmet meal with
wine
or champagne. The flight does not take long, only about
three-and-a-half hours. As you approach New York, the plane
slows down, descends and the plane's nose comes down. You
touch down in New York at 9:30 a.m., one hour before you left
London.
Photo courtesy British Airways A Concorde landing
More than 2.5 million people have flown on the Concorde.
The cost of your Concorde flight from London to New York is
about $5,100 (£3,521 British) one way!
Future SSTs As of 2000, plans are to improve
the Concorde in terms of safety and comfort. New seats and
cabin lighting are being installed to improve the passenger's
experience onboard the plane.
In addition to the Concorde, other supersonic planes are
currently under design. President Ronald Reagan called for a
program to develop a hyperspace transport or
National Aerospace Plane capable of going from New York
to Tokyo in two hours.
Photo courtesy NASA One concept of the National Aerospace
Plane
Photo courtesy NASA Another concept of the National Aerospace
Plane
Such planes would
have to enter outer space in a suborbital flight. They
would have to develop the air-breathing
rocket engines necessary to achieve the appropriate speeds
and deal with the intense heat of re-entry, much like the space
shuttle.
For more information on SSTs and related topics, see the
links on the next page.
