PYESTOCK PROFILES NUMBER ONE: CIRCULATION CONTROLLED CONVERTIPLANE [Main Title]
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- Title: PYESTOCK PROFILES NUMBER ONE: CIRCULATION CONTROLLED CONVERTIPLANE [Main Title]
- Film Number: AMY 668
- Other titles:
- Summary: A technical film produced by the National Gas Turbine Establishment (NGTE) about the development of circulation controlled convertiplanes. The NGTE undertakes research for jet engines (gas turbines) in collaboration with commercial manufacturers. The ability for fixed wing aircraft to take off and land vertically has been made possible by the development of the deflectable nozzle as used in the Harrier aircraft. Helicopters (rotary wing aircraft) achieve vertical movement by means of a rotating rotor, with blades of adjustable pitch. The function of this rotor can be simulated with a rotor with fixed blades that comprise hollow, perforated tubes, into which high pressure air is injected. This process, incorporated in an aircraft, is referred to as Circulation Controlled Convertiplanes. The potential use of this development for use with fixed wing aircraft is demonstrated. The pioneering work of Frank Whittle is acknowledged at the beginning and end of the film.
- Description: Film opens with a model aircraft modified with a large, spinning twin arm rotor mounted above the centre of the fuselage, taking off and landing vertically. The operator controls the speed of the rotor and simulates vertical movement by moving a vertical rod. The model represents a conventional jet passenger aircraft, and a label by the exhibit reads “VTOL by circulation control”. Film cuts to archive footage of Frank Whittle working on his jet design in 1930, followed by clips of civil and military jets: Whittle test flight, Meteor, Canberra, Comet, Vulcan, BAC 1-11, VC 10, Buccaneer, and the Red Arrows. Research by Rolls Royce, Bristol Siddeley and the NGTE at Pyestock has been fundamental to the development of these and other jet aircraft, illustrated by views of the workshops and test facilities at the NGTE.The introduction of jet aircraft has given rise to more noise and longer runways to accommodate them and can cause discomfort to those living nearby. Helicopters do not need runways as demonstrated by footage of British European Airways (BEA) helicopter G-ASNL in flight and landing. The problem has been to harness the power of a gas turbine to provide horizontal thrust for normal flight and downward thrust for vertical ascent and descent. Rolls Royce developed a series of small jet engines for use singly or multiples in helicopters. The latest engines can lift twenty times their own weight. Bristol Siddeley developed another device, the deflectable nozzle to provide vertical thrust, known as vectored thrust, illustrated by footage of the P1127, the forerunner of the Harrier jet taking off. Scientists and Engineers at Pyestock have developed a new technique called “Circulation Control” by blowing. The device is a long rotating cylinder with a series of longitudinal slots separated by longitudinal holes. Placed in a wind tunnel and when additional air is blown into the open ends of the cylinder, the device rises, i.e. lift is produced. This has provided the key to a simplified form of helicopter, illustrated by footage of a Royal Navy Wessex helicopter in flight. The film returns to the model fixed wing passenger jet aircraft. This is an unstable arrangement and can cause the aircraft to roll, tilt or roll over, because of asymmetric lift. Replacing the twin bladed rotor on the fuselage with a circulation controlled rotor overcomes this effect. Only when the rotor reaches the correct running speed is the circulation control switched on to achieve lift, illustrated by footage of a test rig at Pyestock of a jet engine and rotor running. The rotor is essentially two hollow tubes that have air blown into them by a “commutator” that effectively simulates the variable pitch of the conventional rotor blades. A schematic diagram shows how the cyclic and collective controls the tube rotors by means of variable and selective air jets. The cyclic control remains within the non rotating part of the rotor hub. Tests to determine the interaction effect between the aircraft wings and the rotor are conducted in a large air tunnel at the Royal Aircraft Establishment, Farnborough. Research on other projects had priority access to the tunnel so an impressive test rig was constructed on a heavy lorry chassis. The rotor and the Avon jet engine mounted on a sub-frame are attached to the chassis by rubber dampers, to separate the vibration sources from both the vehicle and the rotor arms. The thrust of the Avon engine is also used to increase the speed of the vehicle, and a rotating nozzle provides reverse thrust to assist the vehicle to slow down. Camera shots inside and outside of the running vehicle are most impressive, particularly when the Avon thrust is deployed. With such equipment the development of the circulation controlled rotor will proceed apace. Film closes with footage of Frank Whittle, who the commentary notes “gave us the jet engine”.
- Access Conditions: Attribution: © IWM (AMY 668)
- Featured Period:
- Production Date: 1966
- Production Country: GB
- Production Details: Ministry of Aviation (Production sponsor) National Gas Turbine Establishment (Production company)
- Personalities, Units and Organisations:
- Physical Characteristics: Colour format: Colour Sound format: Sound
- Technical Details: Format: 16mm Number of items/reels/tapes: 1 Footage: 551ft; Running time: 15 mins
- Notes: Remarks: The opening titles acknowledge the assistance of Rolls Royce Ltd, the Royal Aircraft Establishment and Mr Matthew Nathan.
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