There have been aviation incidents in which the control surfaces became unavailable, typically due to loss of hydraulics. Aircraft are not designed to be flown in such circumstances (which is why they have redundant hydraulics), but a few pilots have had some success in controlling such aircraft. The biggest challenge is to avoid the phugoid instability mode, which requires careful use of the throttle. Citing the U.S. National Transportation Safety Board, an aviation accident is defined as an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person... Aircraft flight controls allow a pilot to adjust and control the aircrafts flight attitude. ... A phugoid is one of the flight dynamics modes of an aircraft (others include short period, dutch roll, and spiral divergence). ... Aircraft engine controls provide a means for the pilot to control and monitor the operation of his aircrafts powerplant. ...

The basic means of controlling the airplane is by making use of the position of the engine(s). If the engines are mounted under the centre of gravity, as is the case in most passenger jets, then increasing the thrust will raise the nose, while decreasing the thrust will lower it. This control method may call for control inputs that go against the pilot's instinct: when the plane is in a dive, adding thrust will raise the nose and vice versa. In physics, the center of gravity (CoG) of an object is the average location of its weight. ...

Additionally, asymmetrical thrust may be used for directional control: if the left engine is idled and power is increased on the right side this will result in a yaw to the left, and vice versa. If throttle settings allow the throttles to be shifted without affecting the total amount of power, then yaw control can be combined with pitch control. If the plane is yawing, then the wing on the outside of this yaw movement will go faster than the inner wing. This creates higher lift on the faster wing, resulting in a rolling movement, which helps to make a turn.

Controlling speed is very difficult with engine control only, and this will most likely result in a fast landing, which is required anyway if the flaps can not be extended due to loss of hydraulics, which probably caused the loss of control surfaces in the first place. Only passenger jets with an engine mounted on the tail, such as a DC-10, MD-11 or Lockheed Tristar, will be able to control the speed to a higher degree, as this engine is on the fuselage centreline and above the centre of gravity. On the other hand, planes that have two or four engines mounted on the tail (as is the case with most business jets), will only have limited benefit from asymmetrical thrust. Biman Bangladesh Airlines McDonnell Douglas DC-10 The McDonnell Douglas DC-10 is a three-engined long-range airliner, with two engines mounted on underwing pylons and a third engine at the base of the vertical stabilizer. ... Varig MD-11 The McDonnell Douglas MD-11 is a Widebody Trijet powered by three engines. ... Orbital Sciences Stargazer Lockheed L-1011 The Lockheed L-1011 TriStar was the third widebody passenger jet airliner to reach the marketplace, following the Boeing 747 jumbo jet and the Douglas DC-10. ...

• American Airlines Flight 96 on June 12,1972. Failure of cargo door causes explosive decompression, which caused floor to collapse and severed flight controls on DC-10 Aircraft. Pilots had a jammed rudder, limited ailerons and limited elevators. Engine 2 shifted to idle at time of decompression. Aircraft landed safely at Detroit Metro.
• Turkish Airlines Flight 981 on March 3,1974. Failure of cargo door causes explosive decompression, which caused floor to collapse and severed flight controls on DC-10 Aircraft. Engine 2 flamed out at time of decompression.
• Japan Airlines Flight 123 on August 12, 1985. Lost the vertical stabilizer due to mechanical failure. The pilots were only partially able to regain control of the aircraft.
• United Airlines Flight 232 on July 19, 1989. All control surfaces failed. Dennis Fitch, a deadheading DC-10 instructor who had studied the case of JAL Flight 123, was able to help the pilots fly the plane in a limited fashion.
• Philippine Airlines Flight 434 on December 11, 1994. Hydraulics damaged due to a bomb in the passenger cabin.
• DHL Flight on 22 November, 2003. The first jet airliner to land safely without any hydraulics.

American Airlines Flight 96 was a regular DC-10 commuter flight operated by American Airlines, with a scheduled route from Detroit, Michigan to Buffalo, New York. ... Explosive decompression (ED) is a sudden drop in pressure that occurs in 0. ... For the band with a similar name, see The Ailerons Ailerons are hinged control surfaces attached to the trailing edge of the wing of a fixed-wing aircraft. ... A set of lifts (elevators) in the lower level of a London Underground station. ... Detroit Metropolitan Wayne County Airport (IATA:DTW, ICAO:KDTW), also called Detroit Metro Airport, is an airport in Romulus, Michigan, near Detroit, Michigan, and is a major hub for Northwest Airlines. ... Turkish Airlines Flight 981 was a flight that flew on an Ankara–Orly International Airport (near Paris)–London Heathrow Airport (London) route. ... Japan Airlines Flight 123 was a JAL domestic flight from Tokyo International Airport in Haneda to Osaka International Airport in Itami, Hyogo. ... The vertical stabilizer or fin of an aircraft is found on its tail, generally pointing straight upward. ... United Airlines flight 232 was a scheduled flight operated by United Airlines between Denver and Philadelphia via Chicago. ... Dennis E. Fitch (Denny Fitch) (born 1943) was the off-duty DC-10 training captain who helped captain Al Haynes save United Airlines Flight 232 when all flight controls were lost, on 19 July 1989. ... Philippine Airlines Flight 434 was the route designator of a flight that flew on a Ninoy Aquino International Airport near Manila, Philippines - Mactan-Cebu International Airport, Cebu - New Tokyo International Airport (Now Narita International Airport), Narita, Japan near Tokyo route. ... The DHL shootdown incident in Baghdad occured on 22 November 2003, aboard an Airbus A300 cargo plane, registered OO-DLL, operating on behalf of DHL. // Events The aircraft took off from Baghdad International Airport to Bahrain International Airport at 06:30 UTC with a crew of three: two Belgians and...

External links

• Touchdown: the Development of Propulsion Controlled Aircraft at NASA-Dryden by Tom Tucker.