The Chinook Block II (CH-47F Block II) is a U.S. Army program focused on a series of improvements that increase payload, provide commonality across the fleet, and create a foundation for affordable future upgrades. The Block 2 aims for a payload of 22,000 lb (10,000 kg) with 4,000 ft (1,200 m) and 95 °F (35 °C) high and hot hover performance, eventually increased up to 6,000 ft (1,800 m), to carry the Joint Light Tactical Vehicle; maximum takeoff weight would be raised to 24,500 kg (54,000 lb). It features the composite-based Advanced Chinook Rotor Blade (derived from the cancelled RAH-66 Comanche) 20% more powerful Honeywell T55-715 engines, and the active parallel actuator system (APAS)
The Block 2 enhancements, which are being developed for the US Army’s wider CH-47F fleet, include the Advanced Chinook Rotor Blade (ACRB), which features geometry and a new asymmetric aerofoil to increase the aircraft’s lift capacity by about 1,500 lb (680 kg) at 4,000 ft and 35 °C in the hover (the army’s 4K/95 performance benchmark). The Advanced Chinook Rotor Blades (ACRBs) and a more pointed nose for avionics growth will be the two features that enable physical identification of a Block 2 Chinook from its Block 1 predecessor. It also includes a new drive system to accommodate the higher torque levels; a single segment fuel tank in each side sponson, compared with the three now; electrical system enhancements; and some other unspecified improvements.
The active parallel actuator system enhances the digital advanced flight-control system, providing an exact torque split between the rotors for greater efficiency. A new fuel system combines the three fuel cells in each sponson into one larger fuel cell and eliminating intracell fuel transfer hardware, reducing weight by 90 kg (200 lb) and increasing fuel capacity. Electrical capacity is increased by three 60 kVA generators. Chinook Block II (CH-47F Block II) will also open the door to an improved engine for the Chinook, via the Future Affordable Turbine Engine (FATE) programme.
The Boeing CH-47 Chinook is an American twin-engined, tandem rotor, heavy-lift helicopter developed by American rotorcraft company Vertol and manufactured by Boeing Vertol (later known as Boeing Rotorcraft Systems). In 2001, the first CH-47F, an upgraded CH-47D, made its maiden flight; the first production model rolled out on 15 June 2006 at Boeing’s facility in Ridley Park, Pennsylvania, and first flew on 23 October 2006. AgustaWestland assembles the CH-47F under license, known as the Chinook ICH-47F, for several customers. Boeing delivered 48 CH-47Fs to the U.S. Army through August 2008; at that time Boeing announced a $4.8 billion contract with the Army for 191 Chinooks.