The story began in 1947 with the issue of an Air Ministry requirement for new fighter aircraft. To counter the threat of a nuclear attack by high altitude bombers, both day and night fighters with all-weather capability would be needed.
Specification F3/48 was for a single seat day fighter and was fulfilled by the Hawker Hunter. Specification F4/48, for a two-seat night fighter, was initially to be fulfilled either by De Havilland or Gloster, who had both submitted proposals. On the 13th of April 1949, contracts were issued to both companies to build prototypes.
De Havilland’s project was the DH110, which was later to serve with the Royal Navy as the Sea Vixen.
Glosters project P.280 was
a delta-winged aircraft, the design work being assisted by delta-wing
research carried out by Germany during the War. The prototype aircraft
carried the serial WD804. It was designated GA.5 and first flew on the 26th
of November 1951. In July of the following year this aircraft was chosen
in preference to the DH110 and the Ministry of Supply placed an order for
it to go into ‘Super Priority’ production, and officially named it
‘Javelin’.
On
the 26th of November 1951, the first prototype of the Gloster
Javelin made its first flight. The aircraft, serial WD804, took off from
Moreton Valence flown by Gloster’s chief test pilot Squadron Leader W.A.
Waterton and was accompanied by a Gloster Meteor acting as a chase
aeroplane.
The 34 minute flight was basically successful but immediately showed up a problem with buffeting in the airflow around the tail. Immediately after taking off, Sqn Ldr Waterton reported severe vibration in the airframe, becoming more pronounced at higher speed. He thought the problem had something to do with the rudder, so the pilot of the chase plane moved in closer in to inspect it. The other pilot confirmed that the rudder was clearly being buffeted, so Waterton completed some basic flight tests at reduced speed and brought the aircraft back in to land.
Oil emitted from the engines had left streaks on the tail, clearly indicating the shape of the airflow. WD804 was therefore modified with an extension to the rear fuselage decking, to create the distinctive ‘pen-nib’ tailcone, which cured the buffeting problem.
WD804 was lost in 1952 on
its 99th flight while carrying out further development work for
Glosters. The elevators developed a serious flutter and broke away, making
the aircraft very difficult to control. The pilot, Sqn Ldr Waterton,
succeeded in getting the aircraft back on the ground by using the
tailplane trimmer for pitch control. However because of this he was forced
to land at a much higher speed than normal which caused the undercarriage
to collapse on touchdown. The aircraft caught fire and was destroyed but
the pilot escaped unhurt and managed to save the flight data for which he
received the George Medal.
The
second prototype, WD808, had more powerful engines (8200lb) and a
modification to the wing shape was introduced. Instead of the prototype
wing’s triangular shape, the wing was ‘kinked’ at the mid-point of
its leading edge, reducing the angle of sweep on the outboard section to
33.8 degrees. This gave a longer chord at the wing tip, improving
stability at high subsonic speeds and adding to the Javelin’s
manoeuvrability. This wing shape was retained on all future Javelins.
WD808 made its first public appearance at the SBAC show at Farnborough in
1952 where it performed a flying display. It was lost in June 1953 in a
fatal crash after experiencing a ‘super-stall’. At high angles of
attack the elevators were masked from the airflow by the wings and became
ineffective, from which point recovery was impossible. The pilot, Peter
Lawrence, delayed his ejection too long in order to ensure that the
aircraft would land on open ground, sadly his parachute was unable to open
in time. Because of this accident a stall warning system was developed
using a sensor on top of the wing, which activated a buzzer in the
pilot’s headphones if pressure at the leading edge started to drop.
The
third prototype, WT827, was used for armament trials and carried the four
30mm Aden cannons, which were fitted to the early marks of production
Javelins. The radome was changed from a rounded shape to a sharper point
and this feature too, was retained in later production. WT827 was also
used for air-to-air refuelling trials and carried the two 250 gallon
external tanks under the fuselage. In July 1953 it appeared at the
Queen’s Coronation Review of the RAF at Odiham where it performed a
575mph flypast.
The
fourth prototype, WT830 was the first Javelin to exceed the sound barrier.
It was fitted with powered ailerons and was used as an aerodynamic test
aircraft at the A&AEE at Boscombe Down. This was the first time the
aircraft was flown by RAF personnel rather than Gloster's test pilots.
The
fifth and last prototype, WT836, first flew on the 20th July
1954 and was the first Javelin to provide a clear Perspex canopy for the
navigator, again this was retained in all later marks. Previously the rear
cockpit had a metal hood with small portholes, this semi darkness was
intended to improve readability of the radar displays. However it was
later thought that an extra pair of eyes to watch the sky would be a
benefit during air combat.
