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TDR Assault Drone


Photograph of TDR assault drone with torpedo

U.S. Navy


Interstate TDR-1/BQ-4 Assault Drone


Specifications:


Crew

1 for test flights
None operationally

Dimensions

48' by
14.6m by

Weight

2700 lb
5900 kg

Maximum speed      

140 mph
225 km/h

Power plant

2 Lycoming O-435-2 220 hp (163 kW) 6-cylinder air-cooled horizontally opposed piston engines

Range

425 miles
685 km

Armament

None

External Stores

1 2000lb (900 kg) bomb or torpedo
Production 189 TDR-1


The U.S. Navy had experimented with unmanned drones since 1936, but it was not until 1941 that developments in television and radar provided the key components required for a practical drone. The first successful television-guided drone flight took place in April 1942 and the first 100 drones were ordered the same month.

The TDR-1 could carry either a large bomb or torpedo. It was constructed using a low-power engine that required few strategic materials that might compete with conventional aircraft construction. It had a very simple cockpit for test flights, but for operational use the canopy was replaced with a flush fairing and the landing gear were jettisoned after takeoff. The drone had a radar altimeter to automatically maintain altitude until the target was reached, and it was equipped with a television camera that was used to guide the aircraft from a TBF Avenger. The drone had a control radius of at least 30 miles (50 km).

The Navy considered ordering as many as 2000 drones, but the program was given too low priority to quickly overcome the technical challenges involved. Some 46 were expended in combat in the Pacific in 1944, mostly at Bougainville or Cap St. Jacques, with a promising hit rate of 39%, but by then the Navy had already terminated the program. The Army examined a prototype but lost interest before ordering any production drones. The services concluded that the complex electronics would be difficult to maintain in the field and that the system would be easily jammed once the Axis caught on. However, Japanese troops targeted by the weapon were startled by what they believed to be the American use of suicide pilots.

The TDR-1 was the ancestor of both jet-powered cruise missiles and of modern military drones, but in the absence of compact and reliable inertial guidance or jamming-resistant control signal technology, it was simply too far ahead of its time.

Photo Gallery


Photograph of TDR on test flight with  human pilot

U.S. Navy

Photograph of TDR from front

U.S. Navy

3-view diagram of TDR assault drone

Wikimedia Commons

References

Goebel (2010; accessed 2011-11-25)

Parsh (2005; accessed 2011-11-25)


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