The modern design of military aircraft in military aviation has been characterized by the quest for stealth. In one way or another, stealth technology has been imbued in every U.S.-developed fighter and bomber since the 1980s, which include the F-117 Nighthawk, B-2 Spirit, F-22 Raptor, F-35 Lightning II, and the future B-21 Raider.
The main impetus behind this stealth revolution is the growing threat posed by advanced air defense systems. As Dan Ward wrote for TIME, “modern air defense systems are so capable that non-stealth aircraft are roughly incapable of surviving in contested airspace.” Countries like China and Russia have also joined the stealth race, with the Chengdu J-20 and Sukhoi Su-57 fighters respectively.
The quest for stealth has not been easy, however, especially in the case of helicopters. As Ward points out, “Helicopters are inherently ill-suited for stealth, turbine exhaust is loud, the entire fuselage vibrates, and the tail rotor is loud. The thing is just not designed to move about undetected.”
The most famous example of a stealth helicopter is probably the Boeing-Sikorsky RAH-66 Comanche. Developed in the 1990s and early 2000s, the Comanche was the U.S. Army’s attempt to come up with a mainstream stealth helicopter to replace the OH-58 Kiowa. The Comanche featured a smooth, composite fuselage, radar-absorbent materials, and an all-composite, five-blade rotor designed for reduced noise. Although the army has already spent an amazing $7 billion on its development, this program was finally canceled in 2004.
Although the Comanche failed, the stealth helicopters would make a comeback in arguably the most famous military operation of the 21st century: the raid on Osama bin Laden’s compound in 2011. For this mission, UH-60 Black Hawks were altered to fly as stealth aircraft, although the exact details have remained classified.
While the latest developments on stealth helicopters are kept largely in the dark by the public, there is no doubt that the chase for this elusive rotorcraft goes on. Naturally occurring problems with helicopter design are huge, but the prospective advantages of a genuinely stealthy helicopter are too great to ignore by military planners. The search for the perfect stealth helicopter remains an ongoing chapter in the annals of military aviation.