Vertical Takeoff and Landing Aircraft

views updated

Vertical Takeoff and Landing Aircraft (known as VTOL aircraft) debuted in the Korean War primarily in the medevac role. The venerable piston‐powered Bell 47 (H‐13) helicopter provided the U.S. Army with an unprecedented ability to rapidly evacuate wounded personnel for lifesaving treatment. VTOL technology was first used in a significant combat role by U.S. forces during the Vietnam War. This was made possible by the advent of a practical turbine engine, providing excellent horsepower‐to‐weight ratios, coupled with advances in lightweight aluminum honeycomb construction techniques and epoxies that made strong, lightweight airframes possible, and rotor systems vastly improved over the older wooden blades. These technologies culminated in the Bell UH‐1 (Huey), OH‐58 (Kiowa), and AH‐1 (Cobra), the Boeing Vertol CH‐47 (Chinook), the Sikorsky CH‐54 (SkyCrane), and the Hughes OH‐6 (Cayuse). The civilian helicopter fleet during and after the Vietnam War was an outgrowth of the technology pioneered by the military, in which many aircraft were nearly indistinguishable from their military cousins.

One unique VTOL aircraft is the USMC single‐pilot Harrier ground attack/fighter aircraft. Developed by British Aerospace in the 1960s, the Harrier flies in the vertical flight mode solely by vectored thrust from a single engine, allowing overflight with transition to forward jet flight at the flick of a wrist. While rather fuel‐inefficient and very noisy, the Harrier stands alone as the only operational VTOL jet worldwide.

VTOL aircraft have revolutionized combat for the ground forces over the last fifty years, and the technology developed has found numerous uses in the civilian world. Improvements in VTOL technology, such as the U.S. Navy/Marine V‐22 “Osprey” tilt‐rotor aircraft, may someday make VTOL aircraft the rule and eliminate the need for runways in either military or civilian aviation.
[See also Helicopters.]

Mark Cannon