Types of Airplanes
There are a wide variety of types of airplanes. Land planes,
carrier-based airplanes, seaplanes, amphibians, vertical takeoff
and landing (VTOL), short takeoff and
landing (STOL), and space shuttles all
take advantage of the same basic technology, but their
capabilities and uses make them seem only distantly related.
Land planes are designed to operate from a hard surface,
typically a paved runway. Some land planes are specially equipped
to operate from grass or other unfinished surfaces. A land plane
usually has wheels to taxi, take off, and land, though some
specialized aircraft operating in the Arctic or Antarctic regions
have skis in place of wheels. The wheels are sometimes referred
to as the undercarriage, although they are often called, together
with the associated brakes, the landing gear. Landing gear may be
fixed, as in some general-aviation airplanes, or retractable,
usually into the fuselage or wings, as in more-sophisticated
airplanes in general and commercial aviation.
Carrier-based airplanes are a specially modified type of land plane designed for takeoff from and landing aboard naval aircraft-carrier ships. Carrier airplanes have a strengthened structure, including their landing gear, to handle the stresses of catapult-assisted takeoff, in which the craft is launched by a steam-driven catapult; and arrested landings, made by using a hook attached to the underside of the aircraft's tail to catch one of four wires strung across the flight deck of the carrier.
Seaplanes, sometimes called floatplanes or Pontoon Planes, are often ordinary land
planes modified with floats instead of wheels so they can operate
from water. A number of seaplanes have been designed from scratch
to operate only from water bases. Such seaplanes have bodies, or
fuselages, that resemble and perform like boat hulls. Known as
flying boats, they may have small floats attached to their outer
wing panels to help steady them at low speeds on the water, but
the weight of the airplane is borne by the floating hull.
Amphibians, like their animal namesakes, operate from both
water and land bases. In many cases, an amphibian is a true
seaplane, with a boat hull and the addition of specially designed
landing gear that can be extended to allow the airplane to taxi
right out of the water onto land. Historically, some flying boats,
a type of amphibious aircraft, were fitted with so-called
beaching gear, a system of cradles on wheels positioned under the
floating aircraft, which then allowed the aircraft to be rolled
Vertical Takeoff and Landing (VTOL)
airplanes typically use the jet thrust from their engines,
pointed down at the earth, to take off and land straight up and
down. After taking off, a VTOLairplane
usually transitions to wing-borne flight in order to cover a
longer distance or carry a significant load. A helicopter is a
type of VTOLaircraft, but there are very
few VTOL airplanes. One unique type of VTOL aircraft is the tilt-rotor, which has
large, propellerlike rotating wings or rotors driven by jet
engines at the wingtips. For takeoff and landing, the engines and
rotors are positioned vertically, much like a helicopter. After
takeoff, however, the engine/rotor combination tilts forward, and
the wing takes on the load of the craft.
The most prominent example of a true VTOL airplane flying today is the McDonnell Douglas AV-8B Harrier II, a military attack plane that uses rotating nozzles attached to its jet engine to direct the engine exhaust in the appropriate direction.Flown in the United States by the Marine Corps, as well as in Spain and Great Britain, where it was originally developed, the Harrier can take off vertically from smaller ships, or be flown to operating areas near the ground troops it supports in its ground-attack role.
Short Takeoff and Landing (STOL)
airplanes are designed to be able to function on relatively short
runways. Their designs usually employ wings and high-lift devices
on the wings optimized for best performance during takeoff and
landing, as distinguished from an airplane that has a wing
optimized for high-speed cruise at high altitude. STOL airplanes are usually cargo airplanes,
although some serve in a passenger-carrying capacity as well.
The space shuttle, flown by the National Aeronautics and Space Administration (NASA), is an aircraft unlike any other because it flies as a fixed-wing airplane within the atmosphere, and as a spacecraft outside the earth's atmosphere. When the space shuttle takes off, it flies like a rocket with wings, relying on the 3175 metric tons of thrust generated by its solid-fuel rocket boosters and liquid-fueled main engines to power its way up, through, and out of the atmosphere. During landing, the shuttle becomes the world's most sophisticated glider, landing without propulsion.
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