Powerback is used by

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

to move backwards on the ground using the

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

of their

engines An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

along with the aircraft's

thrust reversal Thrust reversal, also called reverse thrust, is the temporary diversion of an aircraft engine's thrust for it to act against the forward travel of the aircraft, providing deceleration. Thrust reverser systems are featured on many jet aircraft ...

. Propeller driven (turboprop) aircraft tend to use powerbacks as a means of reversing; powerbacking is often prohibited by the manufacturer on jet aircraft (with the exception of some jet aircraft with tail mounted engines).

Background

While many aircraft are physically capable of performing powerbacks, many companies impose restrictions on the practice, mainly due to the risk of FOD (

foreign object damage In aviation and aerospace, foreign object debris (FOD), is any particle or substance, alien to an aircraft or system, which could potentially cause damage. External FOD hazards include bird strikes, hail, ice, sandstorms, ash-clouds or obje ...

) from debris propelled into the air. This problem is magnified even more with planes having wing-mounted engines, as their proximity to the ground can exacerbate debris ingestion if powerbacks are used. Small metal objects are particularly dangerous as they can be propelled into terminal windows, employees on the ground or even the aircraft itself. Applying the brakes when backing up also has the potential to cause a

tailstrike In aviation, a tailstrike or tail strike occurs when the tail or empennage of an aircraft strikes the ground or other stationary object. This can happen with a fixed-wing aircraft with tricycle undercarriage, in both takeoff where the pilot rotat ...

. During the 1980s, many aircraft with aft-mounted engines, such as DC-9s,

Boeing 727s The Boeing 727 is an American narrow-body airliner that was developed and produced by Boeing Commercial Airplanes. After the heavy 707 quad-jet was introduced in 1958, Boeing addressed the demand for shorter flight lengths from smaller airpo ...

, and MD-80s used powerbacks to reduce the number of ground personnel required. For example,

Northwest Airlines Northwest Airlines Corp. (NWA) was a major American airline founded in 1926 and absorbed into Delta Air Lines, Inc. by a merger. The merger, approved on October 29, 2008, made Delta the largest airline in the world until the American Airlines ...

' fleet of DC-9 aircraft used powerback operations at certain airports, but discontinued the practice in 2005 citing the need to conserve fuel.

KLM KLM Royal Dutch Airlines, legally ''Koninklijke Luchtvaart Maatschappij N.V.'' (literal translation: Royal Aviation Company Plc.), is the flag carrier airline of the Netherlands. KLM is headquartered in Amstelveen, with its hub at nearby Amste ...

also avoids using the procedure for the same reasons, noting that powerbacks cause extra wear on the engines. In addition, in the United States, restrictions on powerbacks are enforced by the

FAA The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic m ...

, and the local aviation officials. Only certain gates at certain airports are approved for powerbacks, and are usually placarded as such. Many airlines impose stricter safety procedures for powerbacks, which often include disallowing a powerback under certain environmental conditions, such as rain or snow.

Military use

In several US military aircraft such as the

C-130 Hercules The Lockheed C-130 Hercules is an American four-engine turboprop military transport aircraft designed and built by Lockheed Corporation, Lockheed (now Lockheed Martin). Capable of using unprepared runways for takeoffs and landings, the C-130 ...

, the

C-5 Galaxy The Lockheed C-5 Galaxy is a large military transport aircraft designed and built by Lockheed, and now maintained and upgraded by its successor, Lockheed Martin. It provides the United States Air Force (USAF) with a heavy intercontinental-ran ...

and the

C-17 Globemaster III The McDonnell Douglas/Boeing C-17 Globemaster III is a large military transport aircraft that was developed for the United States Air Force (USAF) from the 1980s to the early 1990s by McDonnell Douglas. The C-17 carries forward the name of two ...

, the powerback operation is used to enhance ground maneuverability during taxi operations.

Background

Military use

References

See also