In the 1950s, Bell Helicopter developed a turbine-engine powered utility tactical transport helicopter for the U.S. Army. This single-engine helicopter, known as the UH-1B or “Huey,” proved to be very popular with the U.S. Army and was quickly stretched to give a bigger cabin. This stretched version became known as the UH-1D in the Army and as the Bell 205 in the civilian world. In the mid-1970s this model was stretched still further and with a large Lycoming T55 engine became known as the Bell 214. Shortly thereafter, Bell concluded an agreement with the Iranian Armed Forces for a twin-engine version of this helicopter, using the new General Electric T700/CT7 engine. Bell decided to develop this helicopter as a commercial model in support of perceived demand in support of the offshore oil industry. This model was called the Bell 214 ST (“ST” reportedly standing for “Super Transport”).
The Bell 214 ST is a heavy twin-engine turbine helicopter. It uses a two-bladed rotor with some of the largest composite blades on any helicopter. Each blade is 26 feet long and has a chord of 2.75 feet! The engine used for this helicopter is the General Electric CT7-2A. Two of these engines feed directly into a massive transmission. The tail rotor has only two blades, although these are also large with the diameter of the tail rotor approaching almost 10 feet. The fuselage is made of conventional aluminum alloys and is mounted on either a fixed skid gear or wheeled gear. Bell developed the wheeled gear when operators discovered that when hover taxiing with the skid gear, the rotor downwash created too many problems. The cabin is derived from the Bell 205/212 cabin by stretching it about 3 feet. This large cabin features two pilot seats up front and behind the pilot seats is the passenger or cargo cabin. It has a flat floor and two very large sliding doors. When used for passenger transport, it can seat up to 18. When used for cargo, it can carry about 8,000 pounds internally or externally.
Development of the Bell 214 ST started in 1977 and VFR as well as IFR certification was obtained in 1982. Deliveries started in 1982 and continued until 1990. During this time, 100 helicopters were produced. For a variety of reasons, including the collapse of the oil industry in the mid-1980s, this helicopter never became popular with the operators for who it was intended. In fact, only about 30 are in commercial service. The remainder is with the armed forces of Iraq, Thailand, Peru and several other countries. Recently, with the revived interest in deep-water oil exploration, examples of the Bell 214 ST in good condition are in strong demand.