Span 52 feet 0 inches; length 56 feet 4 inches and height 16 feet 0 inches.
Armament: aircraft were fitted with either two or four 30mm Aden cannon (installed in the wings) and could carry up to four Firestreak
Engines: (starboard) one Sapphire Mk.205 turbojet (later Mk.209), (port) one Sapphire Mk.206 turbojet (later Mk.210).
Maximum weight, 44,700 lbs. Maximum speed was 535 knots at 45,000 feet. Maximum permitted speed, 1.08 Mach (achievable in a dive). Maximum
altitude, 54,000 feet, with 50,000 feet being reached in 9 minutes and 15 seconds.
The T.3 variant, lacking reheat, and having the least powerful engines, (8,000lb. each) took 22 minutes to reach 45,000 feet.
Total fuel capacity was 950 gallons internally, two 250 gallon ventral tanks and up to four 230 gallon tanks underwing (FAW.9R only).
The FAW.8 and 9 both had a liquid fuel engine starting system, which was intended to maintain the very rapid engine starting requirement of
the original specification, allowing for the more powerful engines fitted to these versions. A small cordite cartridge was fired to ignite
the rocket propellant-like liquid fuel. The gas that resulted increased pressure which was fed to the starter turbine. Three cartridges were
installed in the aircraft at a time, being behind the cockpit. However, it was not unusual for all three cartridges to fail. It was common
to leave off the panel giving access to the cartridges until the engines were running, to give the ground crew the earliest possible warning
of something untoward happening. Several aircraft were lost due to fires that resulted from problems on start up.
The reheat system increased the power from 11,000lb. per engine to 12,300lb. When reheat was selected, at high altitude, the fuel pump
output supplied more fuel than the engines required in the “dry” (no reheat) condition and the surplus fuel was fed into the jet pipe
and burnt, increasing the thrust. At low altitude, the output from the fuel pump was only slightly more than the engines required in “dry”
mode. As the reheat system had priority for the fuel, this meant overall thrust was less at low altitude than at high altitude. The optimum
minimum height for reheat selection was 20,000 feet.
The Aden 30mm cannons were meant to be an interim fit, although all fighter variants were fitted with four, unless equipped with Firestreak
missiles, when two cannons were removed. The rate of fire was 1,200 rounds per minute, although the maximum number of rounds that could be
fired in a continuous burst was 150 without the guns overheating. The guns were heated by air tapped from the engine compressor casings, and
this gas was also used to remove waste gases when the cannons had been fired. The aircraft had to be within 1,000 yards of the target to
engage it. This was an issue as Soviet bombers were equipped with radar-guided rear-facing cannons with a maximum effective range of 2,000
De Havilland designed and developed the missile that equipped the FAW.7-9 variants. It was codenamed “Blue Jay” and later titled
Firestreak. It had an infra-red seeking guidance system. It was only capable of detecting an aircraft engine from astern and this meant
intercept courses had to position the Javelin behind the enemy aircraft, with the Airborne Interception (AI) radar locking onto the target.
The navigator directed the missile seeker head and could advise the pilot when to launch. Each missile had a 50 lb. high explosive warhead
and the missile could be launched 10,000 feet below the target, with the distance of the Javelin from the target being between one and four
miles. The missiles were fitted on highly aerodynamic pylons under the wings. The top speed of a missile-equipped Javelin was very close to
that of one with no pylons.
The Javelin was described as an easy aircraft to fly, being forgiving and robust. There was a ban on looping.
Individual aircraft details (FEAF relevant details only):