Derek Smith (television producer) looking at life at a US Air Force base at Mildenhall in East Anglia. (1967) Smith produced "The Flight Deck Story", the history of the aircraft carrier, filmed on HMS Eagle and on USS Enterprise off the coast of Vietnam. He also produced "Mission To Hell", which followed the Bishop of Birmingham Leonard Wilson returning to Singapore to tell his story of war time imprisonment by the Japanese Army. Another military history film Smith made at this time was "Jump Jet", the history of the Hawker Harrier, vertical take-off or land aircraft. A film for the series The World About
Power take-off case of a marine application, such shafts may be used to power fire pumps. In aircraft applications, such an accessory drive may be used in conjunction with a constant speed drive. Jet aircraft have four types of PTO units: internal gearbox, external gearbox, radial drive shaft, and bleed air, which are used to power engine accessories. In some cases, aircraft power take-off systems also provide for putting power "into" the engine during engine start. See also Coffman starter Various power transmission methods were available before power takeoffs became common, but there were applications left wanting for some of the attributes