Interstate TDR US Navy Assault Drone

The Interstate TDR was an unmanned “assault drone” developed for the U.S. Navy during World War II.  Like the parallel TDN drone, the TDR was designed to carry an aerial torpedo or a 2,000 pound bomb, the ordnance could either be dropped conventionally or carried directly to the target by the drone.  Here is an early TDR in flight carrying a torpedo.  Markings are standard for early 1942.

Although it was equipped with a conventional cockpit for ferrying and testing, the drone was designed to be piloted by a remote operator flying in a TBM Avenger.  The operator controlled the drone using a television camera mounted in the nose.  The drone was gyro stabilized and carried a radar altimeter.  Effective range of the electronics was eight miles.

The aircraft was constructed of non-strategic materials.  The airframe was made of steel tube by the Schwinn Bicycle Company.  The outer skin was formed plywood fabricated by Wurlitzer Musical Instrument Company.

The production TDR-1 was powered by two Lycoming O-435 engines of 230 hp each giving a top speed of 140 mph.  450 hp Wright R-975 radial engines were also tested on the XTD3R-1 version shown here.  Three prototypes of this version were produced.

The drones were deployed to the Pacific with Special Air Task Group One (STAG-1).  On 30JUL44 they were tested in the Solomon Islands under operational conditions against a beached Japanese freighter, the Yamazuki Maru at Cape Esperance, Guadalcanal.  Video of these tests can be seen here:  https://www.youtube.com/watch?v=CwS669Ipgwc

The Interstate TDRs saw operational use in the Bougainville area and Rabaul where they were used against Japanese shipping and ground targets.  Of the 50 drones used in combat, 31 hit their intended targets.  The Japanese assumed these were manned aircraft and American pilots were deliberately crashing into their targets.

STAG-1 used TDRs in combat from 27SEP44 to 27OCT44. While somewhat successful, the drones were still experiencing technical difficulties and the decision was made to terminate the program in favor of more conventional aircraft.   A total of 189 were produced.

One Interstate TDR has been restored and is on display at the National Naval Aviation Museum at Pensacola Florida.

TDN assault drone here: https://inchhighguy.wordpress.com/2019/03/13/u-s-naval-aircraft-factory-tdn-1-assault-drone/