GB-4

GB-4 (Glide Bomb No.4)
Type	Guided Bomb
Place of origin	United States
Service history
In service	Combat Tested[1][2][3]
Wars	World War II
Production history
Produced	1944
No. built	1,200
Specifications
Mass	2,535 lb (1,150 kg)
Length	12.2 ft (3.7 m)
Diameter	24 in (61 cm)
Warhead weight	2,000 lb (910 kg)
Detonation mechanism	T62 Impact Fuze
Engine	none
Operational range	17 mi (27 km) Preferred
Maximum speed	250–300 mph (400–480 km/h)
Guidance system	Block III (AN/AXT-2) television equipment and remote radio control[1]

GB-4 (Glide Bomb No.4) was a precision guided munition developed by the United States during World War II.[1] GB-4s used a television guidance system with the weapon being steered by a TV bombardier operating a joystick in the launch aircraft.[3]

The first GB-4s (then known as MX-607s) were tested at Eglin Air Force Base during August 1943.[2] During testing the GB-4's circular error probable accuracy was found to be 200 feet (61 m).[1][4] The type was ordered into production on 15 January 1944. Although approved for operational use, the typed suffered from reliability problems throughout testing.[2]

The GB-4 was briefly used in combat[1][3] by the 388th Bomber Group,[2] based in eastern England, but its performance was deemed unsatisfactory.[3] 1,200 GB-4's were delivered to the USAAF however poor combat results lead to a decision to halt further deliveries in February 1945.[2]

See also

• Fritz X
• GB-1
• Azon
• VB-6 Felix

References

1. Guidance and Homing of Missiles and Pilotless Aircraft (Report). AAF (US) Scientific Advisory Group, Wright Field. 1946. p. 5. Archived from the original on 5 February 2022.
2. Zaloga, Steven J (2020). American Guided Missiles of World War II. Osprey. pp. 40–45. ISBN 9781472839275.
3. Rosenberg, Max (1964). The Airforce and the National Guided Missile Program 1944-1950 (Report). USAF Historical Liaison Office. p. 11.
4. OP 1664, US Explosive Ordnance, Volume 2 (Report). Naval Sea Systems Command (NAVSEA). 1947. p. 559.