De Havilland Spectre
Encyclopedia
The de Havilland Spectre was a rocket engine
built by de Havilland
in the 1950s. It was one element of the intended mixed powerplant for combination rocket-jet interceptor aircraft for the Royal Air Force
, such as the Saunders-Roe SR.53
.
and hydrogen peroxide
. The power could be controlled from 10-100% delivering 8,000 lbf (35.7 kN) of thrust at full power. In the SR.53 it used the same fuel tanks as the turbojet engine and if run at full power was expected to consume the full load in about seven minutes.
In 1952 static testing commenced with the Spectre DSpe.l. The aircraft industry had no precedent for an engine which would gain in thrust with altitude and the required maximum thrust was estimated at between 2000 lbf (8.9 kN) and 15000 lbf (66.7 kN) thrust. The design was based on a variable thrust which could be throttled from 8000 lbf (35.6 kN) to 2000 lbf (8.9 kN). Design philosophy was matched to the mixed power concept of an aircraft having both a turbojet and rocket engine for maximum operational flexibility.
Technological innovation embraced the Barske high-speed open-impeller centrifugal pump
s, as formerly researched in the Walter
organisation, regenerative cooling with pump stages both upstream and downstream, gauze catalyst packs, low-loss internal-flow turbine and the use of straight kerosene fuel. The aircraft tanks were to be pressurised to suppress pump cavitation
problems.
It went through rig tests commencing in 1953, bench tests from mid-1954, and testing in two Canberra
s. From flight approval in Autumn 1956, flight experience again posed altitude starvation problems. Clearance was given for flight in the SR.53 prototype from May 1957.
In October 1957 a contract was announced for a more advanced version of the aircraft as the SR.177 to utilise a revised design Spectre DSpe.5 engine together with a reheated supersonic capability 14000 lbf (62.3 kN) thrust Gyron Junior
turbojet engine, thus meeting a full mixed power aircraft concept. In conjunction with the new engine, development had been undertaken with two major ancillaries, a peroxide starter for the gas turbine and a peroxide auxiliary power unit
. Virtually on the heels of the announcement of the contract came the notorious 1957 Defence White Paper
declaring that all future combat would be undertaken by computer controlled missiles, and that manned interceptors were now considered obsolete.
Development flying of the SR.53 continued through 39 flights operating to Mach 1.33, and to altitudes at 55000 ft (16,764 m), as research and construction proceeded on the SR.177, until its cancellation in 1958.
After merging of interests in 1959, it was manufactured by Bristol Siddeley
.
The Spectre project was cancelled in October 1960, at a reported total cost of £ 5.75 million.
nuclear stand off bomb, with two chambers arranged vertically.
The conventional Spectre DSpe.5 had been developed alongside a DSpe.4 RATO variant, the latter for the Avro Vulcan
and Handley-Page Victor V bomber
s, another programme subsequently cancelled after a single trial take-off of a Victor from the de Havilland aerodrome at Hatfield. These two engines were then used in combination to power the development rounds of the Blue Steel missile
stand-off bomb, together with the peroxide APU
, from its first flight in October 1959.
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
built by de Havilland
De Havilland
The de Havilland Aircraft Company was a British aviation manufacturer founded in 1920 when Airco, of which Geoffrey de Havilland had been chief designer, was sold to BSA by the owner George Holt Thomas. De Havilland then set up a company under his name in September of that year at Stag Lane...
in the 1950s. It was one element of the intended mixed powerplant for combination rocket-jet interceptor aircraft for the Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
, such as the Saunders-Roe SR.53
Saunders-Roe SR.53
|- See also :-References:NotesBibliography* Jones, Barry. "Saro's Mixed Power Saga". Aeroplane Monthly, November 1994, Vol 22 No 11 Issue 259. pp. 32–39. London:IPC. ISSN 0143-7240....
.
Design and development
The Spectre was a bipropellant engine burning keroseneKerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
and hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
. The power could be controlled from 10-100% delivering 8,000 lbf (35.7 kN) of thrust at full power. In the SR.53 it used the same fuel tanks as the turbojet engine and if run at full power was expected to consume the full load in about seven minutes.
In 1952 static testing commenced with the Spectre DSpe.l. The aircraft industry had no precedent for an engine which would gain in thrust with altitude and the required maximum thrust was estimated at between 2000 lbf (8.9 kN) and 15000 lbf (66.7 kN) thrust. The design was based on a variable thrust which could be throttled from 8000 lbf (35.6 kN) to 2000 lbf (8.9 kN). Design philosophy was matched to the mixed power concept of an aircraft having both a turbojet and rocket engine for maximum operational flexibility.
Technological innovation embraced the Barske high-speed open-impeller centrifugal pump
Centrifugal pump
A centrifugal pump is a rotodynamic pump that uses a rotating impeller to create flow by the addition of energy to a fluid. Centrifugal pumps are commonly used to move liquids through piping...
s, as formerly researched in the Walter
Hellmuth Walter
Hellmuth Walter was a German engineer who pioneered research into rocket engines and gas turbines...
organisation, regenerative cooling with pump stages both upstream and downstream, gauze catalyst packs, low-loss internal-flow turbine and the use of straight kerosene fuel. The aircraft tanks were to be pressurised to suppress pump cavitation
Cavitation
Cavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...
problems.
It went through rig tests commencing in 1953, bench tests from mid-1954, and testing in two Canberra
English Electric Canberra
The English Electric Canberra is a first-generation jet-powered light bomber manufactured in large numbers through the 1950s. The Canberra could fly at a higher altitude than any other bomber through the 1950s and set a world altitude record of 70,310 ft in 1957...
s. From flight approval in Autumn 1956, flight experience again posed altitude starvation problems. Clearance was given for flight in the SR.53 prototype from May 1957.
In October 1957 a contract was announced for a more advanced version of the aircraft as the SR.177 to utilise a revised design Spectre DSpe.5 engine together with a reheated supersonic capability 14000 lbf (62.3 kN) thrust Gyron Junior
De Havilland Gyron Junior
|-See also:-External links:* *...
turbojet engine, thus meeting a full mixed power aircraft concept. In conjunction with the new engine, development had been undertaken with two major ancillaries, a peroxide starter for the gas turbine and a peroxide auxiliary power unit
Auxiliary power unit
An auxiliary power unit is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft, as well as some large land vehicles.-Function:...
. Virtually on the heels of the announcement of the contract came the notorious 1957 Defence White Paper
1957 Defence White Paper
The 1957 White Paper on Defence was a British white paper setting forth the perceived future of the British military. It had profound effects on all aspects of the defence industry but probably the most affected was the British aircraft industry...
declaring that all future combat would be undertaken by computer controlled missiles, and that manned interceptors were now considered obsolete.
Development flying of the SR.53 continued through 39 flights operating to Mach 1.33, and to altitudes at 55000 ft (16,764 m), as research and construction proceeded on the SR.177, until its cancellation in 1958.
After merging of interests in 1959, it was manufactured by Bristol Siddeley
Bristol Siddeley
Bristol Siddeley Engines Ltd was a British aero engine manufacturer. The company was formed in 1959 by a merger of Bristol Aero-Engines Limited and Armstrong Siddeley Motors Limited. In 1961 the company was expanded by the purchase of the de Havilland Engine Company and the engine division of...
.
The Spectre project was cancelled in October 1960, at a reported total cost of £ 5.75 million.
Variants
Variants included:- Dspe.1 initial version
- Dspe.2 constant thrust version, simpler design
- Dspe.3 development of Dspe.1 with variable thrust
- Dspe.4 development of Dspe.2
- Dspe.5 further development of Dspe.1
Double Spectre
A doubled version of this engine was used for early flight-testing of Blue SteelBlue Steel missile
The Avro Blue Steel was a British air-launched, rocket-propelled nuclear stand-off missile, built to arm the V bomber force. It was the primary British nuclear deterrent weapon until the Royal Navy started operating Polaris missile armed nuclear submarines....
nuclear stand off bomb, with two chambers arranged vertically.
The conventional Spectre DSpe.5 had been developed alongside a DSpe.4 RATO variant, the latter for the Avro Vulcan
Avro Vulcan
The Avro Vulcan, sometimes referred to as the Hawker Siddeley Vulcan, was a jet-powered delta wing strategic bomber, operated by the Royal Air Force from 1956 until 1984. Aircraft manufacturer A V Roe & Co designed the Vulcan in response to Specification B.35/46. Of the three V bombers produced,...
and Handley-Page Victor V bomber
V bomber
The term V bomber was used for the Royal Air Force aircraft during the 1950s and 1960s that comprised the United Kingdom's strategic nuclear strike force known officially as the V-force or Bomber Command Main Force...
s, another programme subsequently cancelled after a single trial take-off of a Victor from the de Havilland aerodrome at Hatfield. These two engines were then used in combination to power the development rounds of the Blue Steel missile
Blue Steel missile
The Avro Blue Steel was a British air-launched, rocket-propelled nuclear stand-off missile, built to arm the V bomber force. It was the primary British nuclear deterrent weapon until the Royal Navy started operating Polaris missile armed nuclear submarines....
stand-off bomb, together with the peroxide APU
Auxiliary power unit
An auxiliary power unit is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft, as well as some large land vehicles.-Function:...
, from its first flight in October 1959.