Armstrong Siddeley Viper

Viper
	Preserved Rolls-Royce Viper turbojet
Type	Turbojet
Manufacturer	Armstrong Siddeley; Rolls-Royce Limited
First run	April 1951
Major applications	BAC Jet Provost; HS Dominie; Aermacchi MB-326
Developed from	Armstrong Siddeley Adder

The Armstrong Siddeley Viper is a British turbojet engine developed and produced by Armstrong Siddeley and then by its successor companies Bristol Siddeley and Rolls-Royce Limited. It entered service in 1953 and remained in use with the Royal Air Force, powering its Dominie T1 navigation training aircraft until January 2011.^[1]

Design and development

The design originally featured a seven-stage compressor based on their Adder engine — the Viper is in effect a large-scale Adder.

Like the similar J85 built in United States, the Viper was originally developed as an expendable engine for production versions of the Jindivik target drone. Like the J85, the limited-life components and total-loss oil systems were replaced with standard systems for use in crewed aircraft.^[2]

Because it was initially developed as an expendable engine, the Viper was subject to many recurring maintenance issues. This led to the development of the first Power by the Hour program in which operators would pay a fixed hourly rate to Bristol Siddeley for the continual maintenance of the engines.^[3]

In the 1970s, Turbomecanica Bucharest and Orao Sarajevo acquired the license for the Viper engine, which propelled various Romanian and Yugoslav built aircraft.^[4]^[5]

Variants

Data from:Jane's All the World's Aircraft 1955-56,^[6] Jane's all the World's Aircraft 1959-60,^[7] Jane's All the World's Aircraft 1962-63^[8]

ASV.1: Short life design study; 1,145 lbf (5.09 kN).
ASV.2: Developed short life version, first run in April 1951; 1,145 lbf (5.09 kN).
ASV.3: (Mk.100) Short life for missile/target applications, flight-tested in the tail of an Avro Lancaster November 1952; 1,640 lbf (7.30 kN).
ASV.4: Short life for missile/target applications first run in 1952, 1,750 lbf (7.78 kN).
ASV.5: (Mk. 101) Extended life version for crewed aircraft.^[6]
ASV.6: Short life for missile/target applications; 1,900 lbf (8.45 kN).
ASV.7
ASV.7/R: ASV.7 with re-heat; 2,470 lbf (10.99 kN).
ASV.8: (became Viper 8 and Mk.102); Long-life version rated at 1,750 lbf (7.78 kN) for Jet Provost T Mk.3.
ASV.9: (became Viper 9 and Mk.103) Similar to ASV.8 with improved turbine materials; 2,000 lbf (8.90 kN).
ASV.10: Long-life version with re-designed Sapphire-style compressor first run in January 1956; 1,900 lbf (8.45 kN).
ASV.11: (became Viper 11 and Mk.200) ASV.10 with increased mass-flow; 2,500 lbf (11.12 kN).
ASV.12: (became Viper 12) up-rated ASV.11 with higher JPT and rated at 2,700 lbf (12.01 kN)
Viper 8: (Mk.102 / Mk.104): Engines for the Hunting-Percival Jet Provost TMk.3 (Mk.102) and GAF Jindivik Mk.102B target drone (Mk.104).
Viper 9: (Mk.103): Powered the Bell X-14 and Handley Page HP 115 among others.
Viper 11: (Mk.200): Powered the Hunting-Percival Jet Provost TMk.4(Mk202) and GAF Jindivik Mk.3 among others.
Viper 12: see ASV.12 above
Viper 20: (Mk.500 series): Powered the Hawker Siddeley HS.125 and Piaggio-Douglas PD.808 among others.
Viper 22: Built under licence by Piaggio for the Aermacchi MB.326
Mk.100: see ASV.3 above
Mk.101: see ASV.5 above
Mk.102: see ASV.8 above
Mk.103: see ASV.9 and Viper 9 above
Mk.104: see ASV.12 above
Mk.200: see Viper 11 above
Mk.201
Mk.202: see Viper 11 above
Mk.204
Mk.301
Mk.521
Mk.522
Mk.525
Mk.601
Mk.632: Built under licence by Turbomecanica and Orao, as the non-afterburning engine for the IAR-93 Vultur A/MB versions, Soko J-22 Orao 1 version, IAR-99 Standard/Șoim versions, and Soko G-4 Super Galeb.
Mk.633: Built under licence by Turbomecanica and Orao, as the afterburning engine for the IAR-93 Vultur B version, and Soko J-22 Orao 2 version.
M.D.30 Viper: Engines licence-built and developed by Dassault Aviation^[6]^[9]
M.D.30R Viper: 2,200 lbf (9.8 kN) with afterburner.^[10]

Applications

Specifications (Viper ASV.12)

Data from ^[11]

General characteristics

Type: Turbojet
Length: 64.0 in (1,625 mm)
Diameter: 24.55 in (624 mm)
Dry weight: 549 lb (249 kg)

Components

Compressor: Seven stage axial
Combustors: Annular, 24 burners
Turbine: Single stage
Fuel type: AVTUR, AVTAG
Oil system: scavenge, metered

Performance

Maximum thrust: 2,700 lbf (12 kN) at 13,800 rpm
Overall pressure ratio: 4.3:1
Air mass flow: 44 lb/s (20 kg/s)
Specific fuel consumption: 1.09 lb/(hr lbf)
Oil consumption:1.25 pt/h (0.7 L/h)
Thrust-to-weight ratio: 4.9

References

Notes

^ Dominie T1 Archived 3 March 2016 at the Wayback Machine www.raf.mod.uk. Retrieved: 14 October 2009
^ Gunston 1989, p.20.
^ "Selling the DH125". Flight Global.
^ About Turbomecanica
^ INCAS - IAR 93 and SOKO /VTJ - J - ORAO Specifications
^ ^a ^b ^c Taylor, John W.R. FRHistS. ARAeS (1955). Jane's All the World's Aircraft 1955-56. London: Sampson, Low, Marston & Co Ltd.
^ Bridgman, Leonard, ed. (1959). Jane's all the World's Aircraft 1959-60. London: Sampson Low, Marston & Co. Ltd.
^ Taylor, John W.R. FRHistS. ARAeS (1962). Jane's All the World's Aircraft 1962-63. London: Sampson, Low, Marston & Co Ltd.
^ Wilkinson, Paul H. (1957). Aircraft engines of the World 1957 (15th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 186–187.
^ Wilkinson, Paul H. (1957). Aircraft engines of the World 1957 (15th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 188–189.
^ Flight Global Archive - 1955 Retrieved: 3 November 2008

Bibliography

Taylor, John W.R. FRHistS. ARAeS (1962). Jane's All the World's Aircraft 1962-63. London: Sampson, Low, Marston & Co Ltd.
Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
Smith, Tom. "Expendable to Indispensable: The Story of a Classic Turbojet - The Viper". Air Enthusiast, No. 55, Autumn 1994, pp. 37–55. ISSN 0143-5450

External links

Rolls-Royce - Viper

[1] Dominie T1 Archived 3 March 2016 at the Wayback Machine www.raf.mod.uk. Retrieved: 14 October 2009

[2] Gunston 1989, p.20.

[3] "Selling the DH125". Flight Global.

[4] About Turbomecanica

[5] INCAS - IAR 93 and SOKO /VTJ - J - ORAO Specifications

[JAWA5556-6] Taylor, John W.R. FRHistS. ARAeS (1955). Jane's All the World's Aircraft 1955-56. London: Sampson, Low, Marston & Co Ltd.

[JAWA1959-60-7] Bridgman, Leonard, ed. (1959). Jane's all the World's Aircraft 1959-60. London: Sampson Low, Marston & Co. Ltd.

[JAWA62-63-8] Taylor, John W.R. FRHistS. ARAeS (1962). Jane's All the World's Aircraft 1962-63. London: Sampson, Low, Marston & Co Ltd.

[AEotW57-9] Wilkinson, Paul H. (1957). Aircraft engines of the World 1957 (15th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 186–187.

[AEotW57(2)-10] Wilkinson, Paul H. (1957). Aircraft engines of the World 1957 (15th ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 188–189.

[11] Flight Global Archive - 1955 Retrieved: 3 November 2008

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

v t e Armstrong Siddeley aero engines
Piston engines	Boarhound Cheetah Civet Cougar Deerhound Genet Genet Major Hyena Jaguar Jaguar Major Leopard Lynx Lynx Major Mongoose Ounce Panther Puma Serval Tiger (V12) Tiger (Radial) Wolfhound
Turbojets	Adder ASX Sapphire Viper
Turboprops	ASP Double Mamba Mamba Python
Rocket engines	Beta Snarler Screamer Stentor Gamma