It has long been the belief that air-to-air missile technology was developed as a result of the increase in speed afforded to aircraft by jet technology. While this certainly spurred on the development of such weapons their genesis can be traced back to the need to destroy heavily armoured, well defended bombers quickly and out of range of the bomber’s own defensive weapons.
This requirement was dramatically highlighted in the Battle of Britain where it was found that the Royal Air Force’s fighter aircraft which were armed with .303 machine guns lacked the hitting power to bypass the German bomber’s protection such as self-sealing fuel tanks. The RAF’s answer was to install 20mm cannon armament which had a better punch and from then on nearly all RAF and Luftwaffe fighters featured some kind of cannon armament culminating in an all-cannon armament in the RAF’s fighters towards the end of the war typified by the Gloster Meteor jet fighter.
For the Luftwaffe the need to destroy well protected bombers quickly became more and more urgent as the war progressed. Fighting a combined force of RAF bombers at night and American bombers by day the Luftwaffe needed a weapon to allow high speed attacks on the formations. The Germans experimented with yet heavier armament using cannons in the 30mm to 40mm range but this became impractical. They therefore looked at ways of launching an explosive device against the bombers which would decimate them in a single pass. This resulted in the development of the first guided air-to-air missile, the Ruhrstahl X-4. This simple weapon was guided by its launch aircraft via a wire trailed behind it. The weapon was never tested in combat but the potential was obvious to all and this led to a number of experiments in to the concept by the victorious allies (it should be noted that while the X-4’s guidance method was not successful for air-to-air use it did lay the ground work for a number of successful anti-tank missiles that used wires for guidance such as MILAN and TOW).
The story of the RAF’s first air-to-air missile begins in 1947 when the British Air Ministry, anticipating a new generation of jet powered bombers capable of 600mph, issued a requirement for an air-to-air missile to arm Fighter Command’s aircraft in the 1950s. The result was the Red Hawk missile project but the weapon looked set to impose such performance limitations on the launch aircraft that, coupled with its complexity, by 1950 the RAF had deemed it impractical and lost interest.
In 1949 however the Ministry of Supply issued a requirement calling for a de-rated weapon that would not impose such a weight penalty and address some of the complex problems associated with it. Known briefly as Pink Hawk, in reference to its ancestor, the project then became known as Blue Sky and development was undertaken by Fairey Aviation. By that time Fairey Aviation’s weapons division was well established in the development of guided weapons having begun research as far back as the closing stages of the war when they worked on developing guided weapons to use against Japanese Kamikaze aircraft. They had also undertaken development of multi-stage weapons culminating in the S.T.V.1 test vehicle that featured four boosters that could be separated in flight.
In mid-1950 the Ministry of Supply were presented with Fairey’s proposal for a beam-riding weapon incorporating two jettisonable rocket boosters to power it to the target. The weapon was small enough to be carried by nearly all jet nightfighters of the period such as the Gloster Meteor. This was necessary as the weapon required a radar equipped launch aircraft to guide it. The Ministry of Supply were sufficiently interested to order a development batch of weapons for firing trials and the weapon was later renamed Fireflash although the blanket term for the trials remained Blue Sky. At the same time the Ministry of Supply also gave the go ahead for De Havilland’s missile project, the infra-red guided Blue Jay, which eventually became the Firestreak.
Fireflash was a two stage missile consisting of the main weapon flanked by two rocket boosters. The weapon itself was essentially an unpowered, guided dart and relied on the boosters to accelerate it to its optimal speed of around Mach 2. This took the boosters approximately 1.5 seconds to achieve after which they were jettisoned allowing the main weapon to continue on to the target. The two rocket boosters were solid fuelled and attached to the dart by a U-shaped separation device that consisted of a tube housing two cylinder mounted pistons. A 0.06lb cordite charge would power the pistons forward when a pressure switch detected that the boosters had extinguished their fuel thus separating the boosters from the main weapon. Stabilising fins on the boosters prevented them from tumbling upon separation which greatly reduced the risk to the aircraft.
The dart itself featured cruciform wings along its centre of gravity and was steered to the target via four steering rudders at the tail positioned at 45 degrees in relation to these wings. The warhead was located near the nose of the dart and was triggered by an early proximity fuse mounted just ahead of it. The guidance systems were located in the rear of the missile ahead of the steering servos that controlled the rudders.
Fireflash was guided to the target via a process known as “beam riding” which was a common guidance system for early air-to-air and surface-to-air missiles. The concept works by having the launch aircraft direct a narrow beam of radar energy at the target which in the case of Fireflash was achieved by synchronising the radar beam to the aircraft’s gun sight. The pilot would aim at the target using the gunsight and then launch the Fireflash keeping the target aircraft in the gunsight throughout the entire engagement. Receivers in the rear of the missile determined the strength of the radar beam in the longitudinal and lateral axis and issue corrections to the rudders in the tail of the dart. The stronger the radar signal the weapon detected then the more it was on course. The entire assembly was designed to rotate immediately after launch so as to offset any asymmetrical thrust produced by one of the boosters producing more thrust than the other which also kept the weapon roughly within the guidance beam.
Test launches of the weapon began in the summer of 1951 using a modified Armstrong-Whitworth (Gloster) Meteor NF.11 fitted with a distinguishable “bump” on the nose that housed the radar beam antenna. The guidance radar on the Meteor and subsequently any other aircraft to be armed with the weapon was an X band system using a helical scan dish meaning the scanner rotated at a slight angle rather than transition from side to side as in a search radar for example.
The first firings were carried out by Fairey Aviation employees I. R. Ryall, acting as pilot, and P. H. Clark, acting as observer. The target aircraft were often Fairey Firefly drones and the early missiles lacked the warhead until the guidance system had been properly tested. Once satisfied that the missile wasn’t about to fly off in to some populated area live firings began shortly afterwards. The RAF were sufficiently interested to keep funding the weapon’s development but De Havilland’s Firestreak project was closing the gap on the lead Fairey was enjoying at the time. Testing of the weapon was proving remarkably trouble free and as 1955 dawned the RAF commissioned the No 6 Joint Services Trials Unit at RAF Valley to continue developing the weapon and perhaps more importantly develop operating principles for RAF use of guided weapons.
Talks now centred on a production contract with the RAF and Fairey requested a minimum order of 1,000 rounds to take in to consideration operational usage and to make the weapon financially viable. It was at this point however that the RAF began to rethink the whole project. Fairey must have known that there were clouds gathering over the project as well for most of their test pilots were combat veterans themselves and had already recognised the weapon’s obvious limitations.
Despite its accuracy, Fireflash was a comparatively short ranged weapon. The unpowered dart, the very “business end” of the weapon, had a maximum range in the region of 2.2 miles (3.5km) whereas De Havilland’s Firestreak was promising a range of 4 miles (6.4km). Assembling the weapon was a tricky and time consuming process that, unless it was already assembled, increased an aircraft’s turnaround time during missions.
The biggest criticism however centred on its method of guidance. On the one hand it proved quite reliable and was largely immune to physical countermeasures such as chaff since the pilot could keep the target in his gunsight and therefore re-establish contact quickly after the chaff had dropped away. However the weapon required what is known in military circles as a “cooperative target” meaning a target that offered the most ideal positioning for a shot which in this case was directly head of the launch aircraft flying straight and level. This was not so much of a problem for an attack on a lumbering bomber or transport aircraft but against a tight turning fighter it was useless. Also, the fact that the launch aircraft had to keep aiming at the target also left it very vulnerable to attack from another aircraft. De Havilland’s Firestreak, which was infra-red guided, had none of these problems.
Intensive trials of the Fireflash continued on but no full-scale production order was ever given and by the time No 6 Joint Services Trials Unit was redesignated No 1 Guided Weapons Development Squadron in 1957 flying 10 modified Supermarine Swift F7s to carry the missile the project was effectively dead. Instead the unit was now tasked with using the weapon to continue developing the operating principles for guided air-to-air weapons that would then be implemented on future weapons. There were efforts to save the project by its supporters who wanted it adopted for the high altitude bomber interception role but anything the Fireflash could do Firestreak (right) could do better and the last units were withdrawn in 1958.
A cynic might say that Fireflash was something of a failure however this ignores the important contribution it made to the RAF and the British weapons technology effort at large. Fireflash has the distinction of being the first British air-to-air guided missile to be fired, the first guided air-to-air weapon fielded by the RAF (albeit in a trials role) and perhaps most significantly gave the RAF valuable experience in handling such weapons. It therefore paved the way for future weapons from Firestreak and Red Top up to today’s AIM-132 ASRAAM and Meteor.
- Wingspan : 2.34ft
- Length : 9.31ft
- Launch Weight : 330lbs
- Speed : Mach 2 (2436 mph)
- Range : 2.2 miles
- Number Built : 300
- Life Span : 1951 – 1958