The Boeing–Sikorsky RAH-66 Comanche is an American stealth armed reconnaissance and attack helicopter designed for the United States Army. Following decades of study and development, the RAH-66 program was canceled in 2004 before mass production began, by which point nearly US$7 billion had been spent on the program.
The Bell XV-15 is an American tiltrotor VTOL aircraft. It was the second successful experimental tiltrotor aircraft and the first to demonstrate the concept's high speed performance relative to conventional helicopters.
The Sikorsky S-76 is a medium-size commercial utility helicopter designed and produced by the American helicopter manufacturer Sikorsky Aircraft. It is the company's first helicopter specifically developed for the civilian market.
The Bell 222 is an American twin-engine light helicopter built by Bell Helicopter. The Bell 230 is an improved development with different engines and other minor changes.
The Curtiss-Wright X-19, company designation Model 200, was an American experimental tiltrotor aircraft of the early 1960s. It was noteworthy for being the last aircraft of any kind manufactured by Curtiss-Wright.
In safe-life design, products are intended to be removed from service at a specific design life.
On a helicopter, the main rotor or rotor system is the combination of several rotary wings with a control system, that generates the aerodynamic lift force that supports the weight of the helicopter, and the thrust that counteracts aerodynamic drag in forward flight. Each main rotor is mounted on a vertical mast over the top of the helicopter, as opposed to a helicopter tail rotor, which connects through a combination of drive shaft(s) and gearboxes along the tail boom. The blade pitch is typically controlled by the pilot using the helicopter flight controls. Helicopters are one example of rotary-wing aircraft (rotorcraft). The name is derived from the Greek words helix, helik-, meaning spiral; and pteron meaning wing.
The Sikorsky CH-53K King Stallion is a heavy transport helicopter designed and produced by Sikorsky Aircraft. The King Stallion is an evolution of the long running CH-53 series of helicopters which has been in continuous service since 1966, and features three up-rated 7,500 shp (5,590 kW) engines, new composite rotor blades, and a wider aircraft cabin than its predecessors. It is the largest and heaviest helicopter in the U.S. military.
The Bell 533 was a research helicopter built by Bell Helicopter under contract with the United States Army during the 1960s, to explore the limits and conditions experienced by helicopter rotors at high airspeeds. The helicopter was a YH-40—a preproduction version of the UH-1 Iroquois—modified and tested in several helicopter and compound helicopter configurations. The Bell 533 was referred to as the High Performance Helicopter (HPH) by the Army, and reached a top speed of 274.6 knots in 1969, before being retired.
The Sikorsky S-72 was an experimental Sikorsky Aircraft compound helicopter developed as the Rotor Systems Research Aircraft (RSRA) for the National Aeronautics and Space Administration (NASA) and the United States Army. The RSRA was a testbed for rotor and propulsion systems for high-speed.
The Boeing Vertol YUH-61 was a twin turbine-engined, medium-lift, military assault/utility helicopter. The YUH-61 was the runner-up in the United States Army Utility Tactical Transport Aircraft System (UTTAS) competition in the early 1970s to replace the Bell UH-1 Iroquois helicopter. At the end of the flyoff program, Sikorsky Aircraft was awarded a contract to develop and build its UH-60A entry.
The Sikorsky S-75 was a proof-of-concept all-composite helicopter. Sikorsky Aircraft used all-composite materials to replace metal to provide greater strength, lighter weight, lower manufacturing costs, and reduce maintenance costs.
The McDonnell XV-1 is an experimental Convertiplane developed by McDonnell Aircraft for a joint research program between the United States Air Force and the United States Army to explore technologies to develop an aircraft that could take off and land like a helicopter but fly at faster airspeeds, similar to a conventional airplane. The XV-1 would reach a speed of 200 mph, faster than any previous rotorcraft, but the program was terminated due to the tip-jet noise and complexity of the technology which gave only a modest gain in performance.
The Boeing Model 360 is an American experimental medium-lift tandem rotor cargo helicopter developed privately by Boeing to demonstrate advanced helicopter technology. The aircraft was intended as a technology demonstrator, with no plans to put the type into production, and many of its design features were carried onto other programs including the RAH-66 Comanche and V-22 Osprey. The sole prototype has been preserved and is a static exhibit at the American Helicopter Museum in West Chester, Pennsylvania.
The Sikorsky S-52 is a utility helicopter developed by Sikorsky Aircraft in the late 1940s. It was used by the U.S. Navy, Marine Corps, and Coast Guard. The S-52 was the first US helicopter with all-metal rotor blades. Initially a two-seater, it was developed into the four-seat S-52-2 and S-52-3. It was designated HO5S-1 by the U.S. Navy and Marine Corps, HO5S-1G by the Coast Guard, and YH-18A by the U.S. Army, and was used extensively by civil operators after being retired by the military.
The Light Helicopter Experimental (LHX) program was a 1980s United States Army helicopter procurement project to replace the AH-1 Cobra and OH-58 Kiowa helicopters. The result of this program lead to the development of the RAH-66 Comanche, which was cancelled before entering production.
The Sikorsky S-97 Raider is a high-speed scout and attack compound helicopter based on the Advancing Blade Concept (ABC) with a coaxial rotor system under development by Sikorsky Aircraft. Sikorsky planned to offer it for the United States Army's Armed Aerial Scout program, along with other possible uses. The S-97 made its maiden flight on 22 May 2015.
Future Vertical Lift (FVL) is a plan to develop a family of military helicopters for the United States Armed Forces. Five different sizes of aircraft are to be developed, sharing common hardware such as sensors, avionics, engines, and countermeasures. The U.S. Army has been considering the program since 2004. FVL is meant to develop replacements for the Army's UH-60 Black Hawk, AH-64 Apache, CH-47 Chinook, and OH-58 Kiowa helicopters. The precursor for FVL is the Joint Multi-Role (JMR) helicopter program.
The Bell 525 Relentless is an American super-medium-lift helicopter, under development by Bell Textron. The Bell 525 was unveiled at the 2012 Heli-Expo in Dallas, Texas in February 2012. The helicopter first flew on 1 July 2015. It is designed to transport up to 19 passengers. The aircraft is the first fly-by-wire civilian aircraft and suffered a crash of its prototype, and is still slowly working towards certification. As of 2024 Bell is still working towards completing flight certification but already has its first order.
The Bell V-280 Valor is a tiltrotor aircraft being developed by Bell Helicopter for the United States Army's Future Vertical Lift (FVL) program. The aircraft was officially unveiled at the 2013 Army Aviation Association of America's (AAAA) Annual Professional Forum and Exposition in Fort Worth, Texas. The V-280 made its first flight on 18 December 2017 in Amarillo, Texas.
