Stealth helicopter

Stealth helicopters are helicopters that incorporate stealth technology to decrease an enemy's detection ability.^[1] There are a diverse range of technologies used to achieve this decreased detectability; these have largely involved the reduction of several different signatures typically generated by a rotorcraft, including those of noise, radar, and infrared.

In many ways, helicopters are less suitable for stealth technology than fixed-wing aircraft are; one such area is their rotor blades, which not only generate copious noise levels but can also give off a strong radar signature. However, blade designs have been developed that can significantly reduce noise,^[2] which has traditionally been a major issue for any operation involving the clandestine use of helicopters.^[3] Numerous helicopters have incorporated profiled fuselages to reduce their radar cross-section (RCS), constructing elements of the rotorcraft from certain materials is another means of minimising radar visibility.

It is known that some nations have used such rotorcraft operationally, albeit in a limited scope, since the 1970s; a modified Hughes 500P was used by the Central Intelligence Agency (CIA) during the Vietnam War. Various helicopters have been furnished with infrared exhaust suppressors to reduce their vulnerability to infrared homing weapons. Attack helicopters, such as the Changhe Z-10, Eurocopter Tiger, and HAL Prachand have incorporated numerous presence reduction technologies into their design to increase their survivability. The raid on the compound of Osama bin Laden in May 2011 utilized what appeared to be two Sikorsky UH-60 Black Hawks, heavily modified for quieter operations and employing stealth technology to be less visible to radar.^[4][5] Furthermore, various nations have stated their ambitions to introduce their own stealth helicopters.