American air-launched drone, development started in 1954. Program cancelled in 1959.

Historical Essay © Andreas Parsch

Northrop (Radioplane) Q-4/AQM-35

In 1955, Northrop's Radioplane division started the development of a supersonic target drone for the USAF under the Q-4 designator. The first air launch of an XQ-4 occurred in January 1956, and the first ground launch six months later. The XQ-4 was powered by an XJ81-WE-3 turbojet engine, and could reach a speed of around Mach 2. The test and evaluation phase of the XQ-4 was relatively long, and it didn't enter limited service until around 1958. It was normally air-launched (e.g. by B-50 or DC-130 aircraft), guided by radar, and recovered by a three-stage parachute system. It was used to test various types of air-to-air and surface-to-air missiles designed for use against supersonic enemy aircraft. Optionally, the Q-4 could also be fitted with photographic or TV reconnaissance equipment.

The XQ-4A was specifically designed to meet the radar-appearance requirements for testing the IM-99/CIM-10 Bomarc missile, but it was apparently not built in large numbers. The XQ-4B model, some or all of which were built by Bendix, first flew in 1960. It was an improved version with the significantly more powerful J85-GE-5 engine.

My sources don't reveal many details about the operational career of the Q-4 family of drones, and they probably never became fully operational with the USAF. Around 1961, however, the Air Force at least formally ended the experimental evaluation phase, and redesignated the XQ-4A and XQ-4B as Q-4A and Q-4B, respectively (it's also possible that the Q-4A designator applied to the service model of the XQ-4).

In June 1963, the Q-4A and Q-4B were redesignated as AQM-35A and AQM-35B, respectively. It seems that only relatively few drones of the Q-4/AQM-35 family were built (less than 100, possibly as few as 25), and they were apparently no longer in use by the mid-1960s.

Note: There are a few sources which call the AQM-35 the "Bendix Talos" and/or refer to RIM-35A or RTM-35A designations. I don't know the origin of these reports, but they are certainly errouneous. There is no way a variant of the AQM-35 could have been built as a ship-launched interceptor missile, and I strongly suspect some major confusion between the Bendix-built AQM-35B and that company's RIM-8 Talos ship-based air-defense missile.

Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for XQ-4, Q-4B (AQM-35B):

[1] Frederick I. Ordway III, Ronald C. Wakeford: "International Missile and Spacecraft Guide", McGraw-Hill, 1960
[2] Norman J. Bowman: "The Handbook of Rockets and Guided Missiles", Perastadion Press, 1963

Manufacturer: Northrop/Bendix. Development Cost $: 84.400 million. in: 1957 average dollars.