Bell 222/230 (Airwolf)

Origins

Bell 222 03In the late 1960s, Bell began designing a new twin turbine engine light helicopter. A mock-up of the new helicopter was displayed in January 1974 at a helicopter convention. Following interest at the convention the company announced the new Bell 222. It was the first light commercial twin turbine engine helicopter developed in the United States.

The Bell 222 incorporated a number of advanced features including dual hydraulic and electrical systems, sponsons housing the retractable landing gear, and the Noda Matic vibration reduction system developed for the Bell 214ST.

Manufacturing began in 1975. The Model 222 first flew on August 13, 1976. It received certification from the Federal Aviation Administration (FAA) on August 16, 1979 and was approved for visual flight rules (VFR) use on December 20, 1979. Helicopter deliveries began on January 16, 1980. The FAA approved the 222 for single pilot instrument flight rules (IFR) operation on May 15, 1980.

Improved versions

The more powerful Bell 222B was introduced in 1982 with a larger diameter main rotor. The 222B-based Bell 222UT Utility Twin, with skid landing gear, was introduced in 1983.

A development of the 222 is the Bell 230, with the 222's LTS 101 engines replaced by two Allison 250 turboshafts, plus other refinements. A converted 222 first flew as the prototype 230 on August 12, 1991. Transport Canada awarded certification in March 1992, and the first production 230 was delivered that November. The 230 had optional skid or wheel undercarriage. Production ended in 1995 with 38 having been built, being replaced in Bell's lineup by the stretched, more powerful Bell 430.

Design

The design includes two main rotor blades of stainless-steel-fiberglass construction and rotor hub with elastomeric bearings, which are lubricant free. Its cabin holds a maximum of 10 persons with 1-2 pilots and 8-9 passengers. Seating configurations include standard seating for a pilot and seven passengers; or executive seating with 1-2 pilots and seating for 5-6. The Bell 222 and 230 are usually flown single-pilot (optional dual controls are available), and can be configured for corporate/executive, EMS or utility transport missions.

The Bell 222 is powered by twin Lycoming/Honeywell LTS101-650 turboshaft engines, rated at 592 shp each. Later 222 versions feature more powerful engines. Engine output is at 100% of rating at 9598 RPM. Two independent drive shafts deliver power from the engines to the transmission. The Bell 222's LST-engine exhaust stacks are located at the rear of the engines, while the 230's Allison-engine exhaust stacks are located high on the cowling. Fuel is stored in three tanks, one in the fuselage and one in each sponson. The main rear landing gear retract into the sponsons.

The Bell 222's rotor systems include:

  • Two-blade, semi-rigid high-kinetic energy main rotor with preconing and underslinging. The rotor head incorporates elastomeric bearings for hub springs, flapping and pitch change bearings. The system is similar in design to that used by the AH-1 Cobra. Rotor speed at 100% engine speed is 348 RPM.
  • All series models incorporate a pusher-type two-bladed tail rotor mounted on the left side of the tailboom, turning at 3396 RPM.

Source: Wikipedia