The CH-47D was the result of June 1976 contract for a modernized Chinook. The improvements included a redesigned cockpit to reduce pilot workload, an advanced flight control system, and improved avionics. The Chinook has two tandem three-bladed counter-rotating fiberglass rotors. The CH-47D is powered by two Allied Signal Engines T55-L-712 3750 shp turboshaft engines and has a maximum speed of 163 mph. The CH-47D made its first flight in May 1979. The CH-47D carry twice the load of a CH-47A and has improved performance. The CH-47D can operate at night and in nearly all weather conditions. The CH-47D is equipped with an air-to-air refueling probe. The Chinook can accommodate a wide variety of internal payloads, including vehicles, artillery pieces, 33 to 44 troops, or 24 litters plus two medical attendants. The "D" model can carry up to 26,000 pounds externally.
