Skyflash AAM
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| BAe Skyflash AAM at the RAF Museum, Cosford, 8 July 2020. (Hugh Llewelyn) |
The Skyflash, or Sky Flash in marketing material, was a medium-range semi-active radar homing air-to-air missile derived from the US AIM-7 Sparrow missile and carried by Royal Air Force F-4 Phantoms and Tornado F3s, Italian Aeronautica Militare and Royal Saudi Air Force Tornados and Swedish Flygvapnet Viggens.
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| A Tornado F3 from 43 Squadron based at RAF Leuchars seen here carrying a full range of armaments. (Sgt Rick Brewell/MOD) |
Skyflash replaced the original Raytheon conical scanning seeker with a Marconi inverse monopulse seeker that worked with the F-4's radar. Monopulse seekers are more accurate, less susceptible to jamming, and able to easily pick out targets at low altitudes.
It offered significantly better performance than the original seeker, allowing British Aerospace to dispense with upgrades to the warhead that were carried out in the US to address poor accuracy.
Panavia Tornado Prototype ADV with semi-recessed Skyflash missiles at Farnborough, England, 4 September 1980. (MilborneOne)
Skyflash was tested in the US, but after trials against experimental monopulse seekers from Raytheon, the United States Navy elected to order a different monopulse-equipped version of the Sparrow, the AIM-7M. Both Skyflash and AIM-7M were later replaced by the more capable AMRAAM.
Design of the Skyflash rocket was started in 1973 by the British Aerospace company on the basis of the American rocket AIM-7E2 "Sparrow". At the stage of development work the missile had the index XJ521.
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| A Saab JA37 Viggen being armed up with an RB71 Skyflash at F13 Wing Bråvalla the missile has been taken up and under the left wing,1 April 1982. (Rune Rydh / Flygvapenmuseum) |
The principal difference between Skyflash" and the American prototype is the homing head. It is equipped with a semi-active radar monopulse homing head, which has greater accuracy and better interference immunity than the homing head conical scanning missile AIM-7E2.
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| Skyflash at the Italian Air Force Museum, Vigna di Valle, 1 April 2012. (Zerosei) |
Flight tests of Skyflash missiles began in November 1975 in the United States at the Pacific Range. During the tests in the summer of 1976, of the seven missiles fired by F-4J fighters at air targets, six flew past targets within the kill range of the combat unit.
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| Saab 37 Viggen No. 37-5 in the air over FMV Vidsel Test Range, Sweden. It's equppied with Skyflash air-to-air missiles, Swedish Air Force designation Robot 71, between 1975 and 1980. (Lennart Johansson / Flygvapenmuseum) |
In 1978, the Skyflash missile was adopted by the British Air Force. It was armed with F-4, "Tornado", F-16 aircraft. The "Skyflash" missile is produced under license in Sweden under the index Av.71 to equip the Swedish fighter-interceptors "Viggen".
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| Saab 37 Viggen No. 37-5 in the air over FMV Vidsel Test Range, Sweden. It's equppied with Skyflash air-to-air missiles, Swedish Air Force designation Robot 71, between 1975 and 1980. (Lennart Johansson / Flygvapenmuseum) |
In the late 1970s in England began work to upgrade the rocket "Skyflash". The new missile was called "Active Skyflash".
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| British Aerospace Skyflash air-to-air missile. Photo taken at the RAF Museum Cosford, Shropshire, England, 16 August 2010. (Rept0n1x) |
The "Skyflash" rocket has an aerodynamic scheme of the "duck" type with a crosswing and stabilizer. The missile retains the appearance of the AIM-7E2, wing compartment, 39.5 kg rods combat unit and the Aerojet Mk.52 Mod.2 or Rocketdyne Mk.38 Mod 4 engine. The 68.5 kg engine has an operating time of about 5 seconds.
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| EAP Leaving Loughborough , 26 March 2012. (Simon Howroyd) |
The rocket "Skyflash" has radar semi-active inversion monopulse SOS of "Marconi" company, which consists of three main easily replaceable blocks: an antenna with a rotation mechanism, a receiver signals and a unit for their processing. The antenna is gyrostabilized and mounted on cardan suspension.
The system works in Cartesian coordinate system, the maximum bearing angle is more than 40°. Light DC electric motors are used in the antenna drive, providing control by azimuth and angle of place.
Receiver head has four receiving antennas, forming three channels of signal processing. PCBs are used in the design of the receiver and signal processing unit. Each subsystem of these units performs an independent function, which facilitates maintenance and repair.
| BAe Skyflash AAM of the BAe EAP at the RAF Museum, Cosford, Shropshire, 8 July 2020. (Hugh Llewelyn) |
The homing head of the Skyflash missile is optimized for joint use with the radar station, which has a continuous radiation channel. The choice of such a station, rather than a pulsed Doppler station, is explained by its greater cost-effectiveness, while a pulsed Doppler radar can be used to point missiles only if the pulse repetition rate is high, which requires a powerful, and therefore larger, and heavier energy source on the aircraft carrier.
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| Skyflash AAM test firing |
Specifications
- Primary function: Medium-range air-to-air missile
- Main Contractor: BAe Dynamics, with Raytheon as subcontractor
- Unit cost: £150,000 per round
- Mass: 193 kg (425 lb)
- Length: 3.68 m (12 ft 1 in)
- Weight: 193 kg (425 lb)
- Diameter: 203 mm
- Warheads: High explosive expanding ring with proximity fuze
- Warhead weight: 39.5 kg (87 lb)
- Engine: Rocketdyne solid propellant rocket motor
- Wingspan: 1.02 m (3 ft 6 in)
- Operational range: 45 km (28 mi)
- Maximum speed: Mach 4
- Guidance system: Marconi inverse monopulse semi-active radar homing
- Users: UK (Royal Air Force), Saudi Arabia (Royal Saudi Air Force), Italy (on leased Tornado F3s), Sweden (Royal Swedish Air Force).
- Date deployed: 1978
- Date retired: Approx 2005-2006.
