Boeing CH-47 Chinook the CH-47 have been developed since the helicopter entered service. The U.S. Army's first major design leap was the now-common CH-47D, which entered service in 1982. Improvements from the CH-47C included upgraded engines, composite rotor blades, a redesigned cockpit to reduce pilot workload, improved and redundant electrical systems, an advanced flight control system, and improved avionics. The latest mainstream generation is the CH-47F, which features several major upgrades to reduce maintenance, digitized flight controls, and is powered by two 4,733-horsepower Honeywell engines. A commercial model of the Chinook, the Boeing-Vertol Model 234, is used worldwide for logging, construction, fighting forest
1994 Scotland RAF Chinook crash data greatly reduced the amount and quality of data available to subsequent investigations. Information on speed and height were derived from the position of cockpit dials in the wreckage, and the wreckage's condition. During 1994, the RAF had begun to fit these recording devices across the Chinook HC.2 fleet prior to the accident; this process was completed in 2002. The aircraft had not been classified as being airworthy. It was mandated upon the RAF that it was "not to be relied upon in any way". The documentary series "Seconds From Disaster" featured the accident in the episode "Chinook Helicopter Crash".