Afterburner – A device for augmenting the thrust of a jet engine by burning additional fuel with unburnt oxygen in the hot gases within the tailpipe.  The process of regular combustion in the combustion chamber is not affected by afterburning. 

Bail out – To jump out of an aircraft by parachute during an emergency.

Barrel Roll – A roll that describes a corkscrew path on the inside of an imaginary barrel. Its three-dimensional flight path helps dissipate forward motion, making it an important tool in air combat both for offensive and defensive purposes.

Battle formation – A loose formation of four aircraft usually in the shape of a box with sides of about 1-2 miles. In an earlier type of battle formation, two aircraft would be laterally spread apart by 1-2 miles, while their two wingmen were offset 45°, about 1,000 ft away on each side.

Blip – A spot of light on a radar screen indicating the position of a detected object, such as an aircraft.

Bogey – An enemy aircraft, as reported by the radar controller or a fellow wingman.

Break – A turn at the maximum possible rate, without regard to depletion of energy. A break is called when an enemy aircraft is sighted within weapon firing range and, shooting down is imminent.

Contact – Visual or radar sighting of an aircraft.

Echelon formation – Aircraft staggered 45° to each other, either close or farther apart.

Eject – To leave an aircraft during an emergency under the power of a rocket-propelled seat, which automatically deploys a parachute after stabilisation.

Escorts – Fighters whose role is to defend the strike aircraft from enemy interceptors. ‘Dedicated’ escorts perform this role exclusively and are configured only for aerial fighting. ‘Armed’ escorts, on the other hand, are basically armed for the strike mission; they double up as escorts after jettisoning their bomb-load, whenever the need arises. 

Hard Turn – An energy-conserving turn, tight enough to ward off a threat that is not imminently dangerous

Infra Red Missile – A short range missile, which homes on to heat radiation from the target’s jet exhaust.

Knots – Nautical miles per hour; a nautical mile is 1.15 times a statute mile.

Mach No – Ratio of the speed of an aircraft to the speed of sound in the surrounding atmosphere; named after Austrian physicist Ernst Mach. An aircraft flying at the speed of sound would thus be flying at Mach 1. The speed of sound varies from 660 knots at sea level to 572 knots at 36,090 feet. This altitude band, known as the troposphere, is characterised by decreasing temperature with increasing altitude. 

Pip – To press the weapon-firing button.

Pipper – Aiming index in an optical gunsight.

Pitch – Aircraft motion about its lateral axis, which causes the nose to lift or descend in relation to the tail.

Reticle – A diamond-shaped or other circular pattern placed in the gunsight optics, for purposes of aiming and sighting.

Roll – Aircraft rotation about its longitudinal axis without changing direction or altitude.

Scramble – An order by a designated air defence control authority for fighters to swiftly get airborne to intercept an intruder. 

Scissors – An air combat manoeuvre in which two fighters repeatedly criss-cross flight paths in an endeavour to get behind the other’s tail. Starting at high speeds, a dogfight usually degenerates into slow speed scissors when neither fighter concedes turning room; eventually, the aircraft with better slow speed features forces an adversary to overshoot and be gunned down. 

Spin – The flight condition of an aircraft in a spiraling, stalled descent. 

Split-S – An air combat manoeuvre in which the aircraft is inverted and pulled down through a half loop, thus not only reversing the direction of travel but also losing height in the process. 

Spoof – Transmit false messages on radio to misguide the enemy aircraft.

Stall – The flight condition when the wings stops producing lift due to airflow disruption at high angles relative to the flight path, causing the aircraft to drop abruptly. 

Vector – Direction of intruder from interceptor, as reported by the radar controller during conduct of an interception.

Wingman – A companion aircraft, which flies in close proximity of the leader. A wingman is primarily tasked with clearing the tail and general area around, while the leader is engaged in combat.

Yaw – Aircraft motion around the vertical axis, which causes the nose to change direction towards left or right.

Yo yo – An air combat manoeuvre, which allows speed to be traded for height or vice versa. In a high-speed yo yo, the attacking aircraft arrests its high rate of closure by zooming up and, after sufficient room is created, dives down obliquely on its turning opponent. In a low-speed yo yo, an attacking aircraft dives down to build up speed and closure before zooming up for an attack. The zooming and diving motion of an attacker is akin to a bouncing yo yo.