English Electric Thunderbird

Thunderbird
Thunderbird I parked at Filton, UK, following a tow vehicle breakdown (1960)
Type	ground to air missile
Place of origin	UK
Service history
Used by	British Army
Production history
Manufacturer	English Electric
Specifications
Length	20 ft 10 in (6.35 m)
Diameter	1 ft 8.7 in (0.527 m)
Warhead	Continuous-rod HE warhead
Wingspan	5 ft 4 in (1.63 m)
Speed	mach 2.7
Guidance system	semi-active radar homing
Launch platform	Single rail, ground mounted (not mobile)

The English Electric Thunderbird was a British surface-to-air missile produced for the British Army. Thunderbird was primarily intended to attack higher altitude targets at ranges up to approximately 30 miles, providing wide-area air defence for the Army in the field. AA guns were still used for lower altitude threats. Thunderbird entered service in 1959 and underwent a major mid-life upgrade to Thunderbird 2 in 1966, before being slowly phased out by 1977. Ex-Army Thunderbird I's were also operated by the Royal Saudi Air Force after 1967.

Thunderbird had performance similar to other semi-portable missiles like the US MIM-23 Hawk and fully mobile Soviet 2K11 Krug, although it pre-dates both of these systems and offered greater range over them, but have slower speed compared to the soviet 2K11 Krug. After its mid-life upgrades, which shared several components with the RAF's Bristol Bloodhound, Thunderbird featured a continuous-wave radar semi-active homing system that was highly resistant to Radar jamming and deception, and was able to track targets even at very low altitudes.

Thunderbird was the Army's only heavy anti-aircraft missile. As missile systems like Thunderbird made flight at medium and higher altitudes practically suicidal, nap-of-the-earth flying became the norm and even shorter-range, faster acting systems were needed. Thunderbird's role was taken over by the much smaller BAC Rapier as they became available.

The Thunderbird originated in a proposal to English Electric in 1949 to develop a missile to provide ground based air defence to the British Army in the field. As such, it was intended to replace the 3.7-inch heavy anti-aircraft gun that fulfilled this role during World War II. Like the 3.7, the new missile would be operated by the Royal Artillery. English Electric created a Guided Weapons Division to work on the project.