In
aviation
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes airplane, fixed-wing and helicopter, rotary-wing types, morphable wings, wing-less lifting bodies, as well as aerostat, lighter- ...
terminology, a rejected takeoff (RTO) or aborted takeoff is the situation in which it is decided to abort the
takeoff
Takeoff is the phase of flight in which an aerospace vehicle leaves the ground and becomes airborne. For aircraft traveling vertically, this is known as liftoff.
For aircraft that take off horizontally, this usually involves starting with a ...
of an
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad ...
.
There can be many reasons for deciding to perform a rejected takeoff, but they are usually due to a suspected or actual problem with the aircraft, such as an engine failure; fire; incorrect configuration; aircraft controllability; environmental conditions such as predictive
windshear; or an instruction from Air Traffic Control.
There are three phases of a takeoff. In the low-speed regime, usually below 80 kts or so, the takeoff will be rejected even for minor failures. In the high-speed regime, above usually 80 kts but below
V1, minor problems are ignored, but the takeoff will still be rejected for serious problems, in particular for engine failures. The takeoff decision speed, known as V
1, is calculated before each flight for larger multi-engine airplanes. Below the decision speed, the airplane should be able to stop safely before the end of the
runway
According to the International Civil Aviation Organization (ICAO), a runway is a "defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft". Runways may be a man-made surface (often asphalt, concrete ...
. Above the decision speed, the airplane may overshoot the runway if the takeoff is aborted, and, therefore, a rejected takeoff is normally not performed above this speed, unless there is reason to doubt the airplane's ability to fly. If a serious failure occurs or is suspected above V
1, but the airplane's ability to fly is not in doubt, the takeoff is continued despite the (suspected) failure, and the airplane will attempt to land again as soon as possible. If the airplane's ability to fly ''is'' in doubt (for instance, in the event of a major flight-control failure which leaves the airplane unable to rotate for liftoff), the best option may well be to reject the takeoff even if after V
1, accepting the likelihood of a runway overrun.
Single-engine aircraft will reject any takeoff after an engine failure, regardless of speed, as there is no power available to continue the takeoff. Even if the airplane is already airborne, if sufficient runway remains, an attempt to land straight ahead on the runway may be made. This may also apply to some light twin-engine airplanes.
Before the takeoff roll is started, the
autobrake system of the aircraft, if available, is armed. The autobrake system will automatically apply maximum brakes if throttle is reduced to idle or reverse thrust during the takeoff roll once a preset speed has been reached.
RTO testing
An RTO is usually seen as one of the hardest tests an airplane has to undergo for its
certification trials. The RTO test is performed under the worst possible conditions; i.e. with fully worn out brakes, the plane loaded to
maximum takeoff weight
The maximum takeoff weight (MTOW) or maximum gross takeoff weight (MGTOW) or maximum takeoff mass (MTOM) of an aircraft is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. The analogous ...
and no use of
thrust reversers
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 to ...
. During an RTO test most of the
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acce ...
of the airplane is converted to heat by the brakes, which may cause the
fusible plugs of the tires to melt, causing them to deflate. Small brake fires are acceptable providing, in the first five minutes, they do not prejudice the safe and complete evacuation of the aircraft.
14 CFR 25.735(g)
/ref>
Accidents involving rejected take-offs
* 2008 South Carolina Learjet 60 crash – an RTO above V1
* Air France Flight 007 – RTO above V1 after flight-control failure, 130 fatalities
* 1990 Wayne County Airport runway collision – RTO after collision following runway incursion
A runway incursion is an aviation incident involving improper positioning of vehicles or people on any airport runway or its protected area. When an incursion involves an ''active'' runway being used by arriving or departing aircraft, the poten ...
; aircraft struck destroyed with 8 fatalities, aircraft that performed RTO damaged with no fatalities, later repaired
* Ameristar Charters Flight 9363 – RTO above V1 after flight-control failure, aircraft written off but no fatalities
* British Airtours Flight 28M – uncontained engine failure that damaged a fuel tank, resulting in a major fire and 55 fatalities
* Garuda Indonesia Flight 865 – RTO after engine failure, 3 fatalities
* TWA Flight 843 – RTO after engine failure
* British Airways Flight 2276 – uncontained engine failure
* Korean Air Flight 2708 – uncontained engine failure
See also
* Balanced field takeoff
References
External links
Airliners.net – Photos detailing a RTO performed by a Lockheed Tristar at Amsterdam Schiphol Airport
with good explanatory notes
*
Boeing 747-8 rejected take-off test, 2011
{{Types of take-off and landing
Emergency aircraft operations
Types of take-off and landing