Ski-jump (aviation)

A ski-jump in aviation is an upward-sloping ramp used to assist aircraft, most often fixed-wing aircraft operating from aircraft carriers, to take off in a shorter distance than would otherwise be possible. By launching the aircraft upwards, the ski-jump provides an initial vertical velocity component, trading horizontal distance for altitude.

The primary benefit of a ski-jump is to allow aircraft to take off with a greater payload (more fuel and/or weapons) or to operate from smaller aircraft carriers that lack catapults. Instead of relying solely on thrust to achieve sufficient airspeed for lift, the ski-jump leverages the conversion of forward momentum into upward trajectory, providing additional time for the aircraft's engines to accelerate it to flight speed.

While ski-jumps are particularly associated with STOL (Short Take-Off and Landing) aircraft, particularly the Harrier Jump Jet and its derivatives, they have also been used to launch conventional fixed-wing aircraft. Upon leaving the ski-jump, the aircraft is briefly airborne while still accelerating. The pilot typically adjusts the aircraft's attitude to maintain controlled flight and continue accelerating to a safe flying speed.

The design of a ski-jump involves factors such as the ramp angle, length, and curvature. These parameters are tailored to the specific aircraft type and the desired launch performance. The effectiveness of a ski-jump depends on factors such as the aircraft's thrust-to-weight ratio, the wind conditions, and the pilot's technique.

Ski-jumps offer a cost-effective and practical alternative to catapults, particularly for smaller or more specialized aircraft carriers. They provide a significant operational advantage by enabling aircraft to operate with increased payload capacity and from a wider range of naval vessels.