Takeoff is the phase of flight in which an aerospace vehicle or animal
goes from the ground to flying in the air.
For aircraft that take off horizontally, this usually involves
starting with a transition from moving along the ground on a runway.
For balloons, helicopters and some specialized fixed-wing aircraft
VTOL aircraft such as the Harrier), no runway is needed.
the opposite of landing.
1 Horizontal takeoff
1.1 Power settings
1.2 Speed required
1.3 Assisted takeoff
2 Vertical takeoff
3 See also
Take off of a hot air balloon
For light aircraft, usually full power is used during takeoff. Large
transport category (airliner) aircraft may use a reduced power for
takeoff, where less than full power is applied in order to prolong
engine life, reduce maintenance costs and reduce noise emissions. In
some emergency cases, the power used can then be increased to increase
the aircraft's performance. Before takeoff, the engines, particularly
piston engines, are routinely run up at high power to check for
engine-related problems. The aircraft is permitted to accelerate to
rotation speed (often referred to as Vr). The term rotation is used
because the aircraft pivots around the axis of its main landing gear
while still on the ground, usually because of manipulation of the
flight controls to make this change in aircraft attitude.
The nose is raised to a nominal 5°–15° nose up pitch attitude to
increase lift from the wings and effect liftoff. For most aircraft,
attempting a takeoff without a pitch-up would require cruise speeds
while still on the runway.
Fixed-wing aircraft designed for high-speed operation (such as
commercial jet aircraft) have difficulty generating enough lift at the
low speeds encountered during takeoff. These are therefore fitted with
high-lift devices, often including slats and usually flaps, which
increase the camber and often area of the wing, making it more
effective at low speed, thus creating more lift. These are deployed
from the wing before takeoff, and retracted during the climb. They can
also be deployed at other times, such as before landing.
The speeds needed for takeoff are relative to the motion of the air
(indicated airspeed). A headwind will reduce the ground speed needed
for takeoff, as there is a greater flow of air over the wings. Typical
takeoff air speeds for jetliners are in the 130–155 knot range
(150–180 mph, 240–285 km/h). Light aircraft, such as a
Cessna 150, take off at around 55 knots (63 mph, 100 km/h).
Ultralights have even lower takeoff speeds. For a given aircraft, the
takeoff speed is usually dependent on the aircraft weight; the heavier
the weight, the greater the speed needed. Some aircraft are
specifically designed for short takeoff and landing (STOL), which they
achieve by becoming airborne at very low speeds.
Three airliners take off simultaneously at Beijing Capital
The takeoff speed required varies with air density, aircraft gross
weight, and aircraft configuration (flap or slat position, as
Air density is affected by factors such as field
elevation and air temperature. This relationship between temperature,
altitude, and air density can be expressed as a density altitude, or
the altitude in the
International Standard Atmosphere
International Standard Atmosphere at which the air
density would be equal to the actual air density.
Operations with transport category aircraft employ the concept of the
takeoff V-Speeds, V1, VR and V2. These speeds are determined not only
by the above factors affecting takeoff performance, but also by the
length and slope of the runway and any peculiar conditions, such as
obstacles off the end of the runway. Below V1, in case of critical
failures, the takeoff should be aborted; above V1 the pilot continues
the takeoff and returns for landing. After the co-pilot calls V1,
he/she will call VR or "rotate," marking speed at which to rotate the
aircraft. The VR for transport category aircraft is calculated such as
to allow the aircraft to reach the regulatory screen height at V2 with
one engine failed. Then, V2 (the safe takeoff speed) is called. This
speed must be maintained after an engine failure to meet performance
targets for rate of climb and angle of climb.
In a single-engine or light twin-engine aircraft, the pilot calculates
the length of runway required to take off and clear any obstacles, to
ensure sufficient runway to use for takeoff. A safety margin can be
added to provide the option to stop on the runway in case of a
rejected takeoff. In most such aircraft, any engine failure results in
a rejected takeoff as a matter of course, since even overrunning the
end of the runway is preferable to lifting off with insufficient power
to maintain flight.
If an obstacle needs to be cleared, the pilot climbs at the speed for
maximum climb angle (Vx), which results in the greatest altitude gain
per unit of horizontal distance travelled. If no obstacle needs to be
cleared, or after an obstacle is cleared, the pilot can accelerate to
the best rate of climb speed (Vy), where the aircraft will gain the
most altitude in the least amount of time. Generally speaking, Vx is a
lower speed than Vy, and requires a higher pitch attitude to achieve.
Normally ground speed for takeoff varies between 250 km/h to 475 km/h
in just 2.94/s.
Main article: Assisted takeoff
Tow line and towing aircraft seen from the cockpit of a glider
Assisted takeoff is any system for helping aircraft into the air (as
opposed to strictly under its own power). The reason it might be
needed is due to the aircraft's weight exceeding the normal maximum
takeoff weight, insufficient power, or the available runway length may
be insufficient, or a hot and high airfield, or a combination of all
Assisted takeoff is also required for gliders, which do
not have an engine and so are unable to take off by themselves.
Vertical takeoff refers to aircraft or rockets that take off in a
vertical trajectory. Vertical takeoff eliminates the need for
airfields. Most vertical take off aircraft are also able to land
horizontally, but there were certain rocket-powered aircraft of the
Luftwaffe that only took off vertically, landing in other ways. The
Bachem Ba 349
Bachem Ba 349 Natter landed under a parachute after having taken off
vertically. Other late
Third Reich projects, such as the Heinkel
P.1077 Julia or the
Focke-Wulf Volksjäger 2 climbed to their ceiling
at a nearly vertical angle and landed later on a skid.
Main article: VTOL
The Harrier Jump Jet, a
A Camcopter S-100, a
VTOL unmanned aerial vehicle
Vertical take-off and landing (VTOL) aircraft include fixed-wing
aircraft that can hover, take off and land vertically as well as
helicopters and other aircraft with powered rotors, such as
VTOL aircraft can operate in other modes
as well, such as
CTOL (conventional take-off and landing),
take-off and landing), and/or
STOVL (short take-off and vertical
landing). Others, such as some helicopters, can only operate by VTOL,
due to the aircraft lacking landing gear that can handle horizontal
VTOL is a subset of V/
STOL (vertical and/or short take-off and
Besides the helicopter, there are two types of
VTOL aircraft in
military service: craft using a tiltrotor, such as the Bell Boeing
V-22 Osprey, and some aircraft using directed jet thrust such as the
A rocket launch is the takeoff phase of the flight of a rocket.
Launches for orbital spaceflights, or launches into interplanetary
space, are usually from a fixed location on the ground, but may also
be from a floating platform such as the San Marco platform, or the Sea
Launch launch vessel.
Balanced field takeoff
Space launch, the spaceflight equivalent
Look up takeoff or take off in Wiktionary, the free dictionary.
Wikimedia Commons has media related to Starts in aviation.
^ Scott, Jeff (4 August 2002) "Airliner
Takeoff Speeds". Aerospace
Web. Retrieved 12 August 2015
^ Ulrich Albrecht: Artefakte des Fanatismus; Technik und
nationalsozialistische Ideologie in der Endphase des Dritten Reiches
Landing Aircraft," John P. Campbell, The
MacMillan Company, New York, 1962.
^ Rogers 1989.
^ Laskowitz, I.B. "Vertical Take-Off and
Landing (VTOL) Aircraft."
Annals of the New York Academy of Sciences, Vol. 107, Art.1, 25 March
^ "Straight Up - A History of Vertical Flight," Steve Markman and Bill
Holder, Schiffer Publishing, 2000.
Types of takeoff and landing
Balanced field takeoff
Takeoff and landing
Launch and recovery cycle
Water landing / Ditching
Floating landing platform
Takeoff and landing
Top of climb
Top of descent