Assisted take-off
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In
Catapults (CATO)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d5/F18-on_catapult.jpg/220px-F18-on_catapult.jpg)
A well-known type of assisted takeoff is an aircraft catapult. In modern systems fitted on aircraft carriers, a piston, known as a shuttle, is propelled down a long cylinder under steam pressure. The aircraft is attached to the shuttle using a tow bar or launch bar mounted to the nose landing gear (an older system used a steel cable called a catapult bridle; the forward ramps on older carrier bows were used to catch these cables), and is flung off the deck at about 15 knots above minimum flying speed, achieved by the catapult in a four-second run.
The
JATO and RATO
JATO stands for 'Jet-assisted takeoff' (and the similar RATO for 'Rocket-assisted takeoff'). In the JATO and RATO systems, additional engines are mounted on the airframe which are used only during takeoff. After that the engines are usually jettisoned, or else they just add to the parasitic weight and drag of the aircraft. However, some aircraft such as the Avro Shackleton MR.3 Phase 2, had permanently attached JATO engines. The four J-47 turbojet engines on the B-36 were not considered JATO systems; they were an integral part of the aircraft's propulsion, and were used during takeoff, climb, and cruise at altitude. The Hercules LC-130 can be equipped with a JATO rocket system to shorten takeoff as used in the LC-130 Skibird for polar missions.[1]
During WW2 the German
Gliders
Glider aircraft which do not have an engine also require an assisted takeoff. Apart from self launching gliders,
Gravity assistance
Early pioneers in powered and unpowered flight used gravity to accelerate their aircraft to a speed which allowed its wings to generate enough lift to achieve independent flight. These included attempts to achieve flight from towers, city walls and cliffs. Generally more successful were attempts in which speed was built up by accelerating down hills and mountain slopes, sometimes on rails or ramps.
Mother ship (carrier) aircraft
Another form of gravity assistance is when an aircraft is released from a larger mother ship or mother craft. This may be because the daughter craft is incapable of taking off normally e.g. the atmospheric flight tests of the Space Shuttle.
Usually the rationale for such a system is to free the daughter craft from the need to climb to its release height under its own power. This allows the daughter craft to be designed with fewer weight and aerodynamic restrictions allowing for exotic configurations to be used or tested, for example the recent
In the interwar years, in order to achieve long ranges with the technology of the time, trials were undertaken with floatplanes piggy-backed atop flying boats. With the floatplane carried part of the way to its destination and freed from having to use any of its own fuel in the initial climb, these combinations could deliver light but time-critical cargos faster and farther than a single individual aircraft (for example the Short Mayo Composite).
Hot air balloons have acted as "motherships" to hang gliders and para gliders in altitude and distance record attempts.
See also
- Colditz Cock glider, for an example of gravity assistance.
- History of aviation, for the work of the early pioneers.
- Silbervogel, a long-range bomber proposal, using a rail-mounted captive rocket booster.
References
- ^ "LC-130 Skibird Aircrews Train for Polar Operations". U.S. DEPARTMENT OF DEFENSE. Retrieved 2018-10-05.
- ^ Part FCL Handbook, EASA. EASA (PDF) (1 ed.). European Aviation Safety Agency.