Nite Gazelle

The Nite Gazelle program was intended to develop a remotely controlled aerial platform with search or search and kill capability. The program used modified QH-50D remotely controlled helicopters as aerial platforms for a number of sensor and sensor/weapon systems. The program was part of Project Blow Hole, which sought to develop a solution to the problem of the Democratic Republic of Vietnam (North Vietnam) not recognizing the agreements governing the demilitarized zone (DMZ) separating them from the Republic of Vietnam (South Vietnam), and frequently using the area to launch artillery fires at allied forces south of the DMZ.

Project Blow Hole was started in late 1967, centering around a meeting on 28 September 1967 between the Advanced Research Project Agency (ARPA; now the Defense Advanced Research Projects Agency or DARPA) and the US Air Force on ways to tackle the problem of gun and rocket artillery in the DMZ. ARPA's Advanced Sensors Office (ARPA-ASO) was the lead agency for the development. In January 1968, ARPA-ASO established the Nite Gazelle program. Blow Hole reportedly shifted its focus to an air-to-ground missile system to counter the DMZ threat, which in turn led to the development of the Laser Aided Rocket System (LARS), which was tested on Nite Gazelle Aircraft.

Nite Gazelle joined a number of efforts relating to Vietnam using the QH-50D drone helicopter. The US Navy had already been using a modified QH-50D, codenamed "Snoopy," to provide reconnaissance support and direction for naval gunfire. At the same time, NADC, Johnsville was modifying 6 QH-50Ds with Low Light Level TV (LLLTV) equipment for use in Vietnam. Nite Gazelle's develop also responded, if indirectly, to a USMC requirement issued on 25 September 1967 for a sensor/weapon system for QH-50 series. In the end, ARPA would use the QH-50 series in at least 6 programs, including Nite Panther, which utilized some of the Nite Gazelle work to provide an immediate real-time battlefield reconnaissance capability, requested by Military Assistance Command, Vietnam (MACV) for US Marines at Khe Sanh later in 1968. The success and continuing requirements for aircraft like Nite Panther helped support the continued work as part of the Nite Gazelle program. Work on a aerostat system, called Silent Joe, which was being developed by ARPA-ASO also fed into Nite Gazelle work.

The modified QH-50Ds used for the Nite Gazelle programs were Navy-owned vehicles bailed to ARPA. The vehicles were either from existing stocks or new vehicles procured by the Navy. As a result, Naval Air Systems Command was designated as ARPA's agent for modification and testing of the Nite Gazelle configured vehicles. All modifications and some initial tests were conducted at the Gyrodyne facility on Long Island, New York. Close coordination of this activity was maintained by the resident Naval officer at the Gyrodyne plant. Gyrodyne was the primary contractor for the QH-50 series of aircraft. Additional tests were conducted at the Naval Air Test Center, Patuxent River, Maryland, where the local Gyrodyne facility was used to support the effort. Technical direction of the Nite Gazelle program was under an ARPA-ASO Program Manager supported by a Program Steering Committee, a Nite Gazelle Weapons Committee, and a Nite Gazelle Sensor Committee. These committees were made up of personnel from: ARPA-ASO; Headquarters, Naval Air Systems Command; Headquarters, US Air Force; Headquarters, Air Force Systems Command; Chief of Naval Operations; Department of the Army; Army Material Command; the Aeronautical Systems Division; and the Defense Communications Planning Group.

System flight tests of the Nite Gazelle system were conducted during between March 1968 and 2 February 1972, using the following sensors and sensor/weapon systems: Day TV camera; LLLTV camera; LLLTV camera with covert infrared light; laser range finder; AN/PPS-5 moving target indication (MTI) radar; electro-optical system; laser range finder/designator; XM18/SUU-14/A dispenser; M129 grenade launcher; M134/GAU-2/A "Minigun"; TRW .50 caliber hypervelocity gun; extended range with control through relay (this system was aerostat-mounted codenamed Grandview); and the Laser-Aided Rocket System (LARS). Two versions of ARPA-ASO's Egyptian Goose MTI radar system, also aerostat-mounted, were also tested in conjuntion with the Nite Gazelle program. The Nite Gazelle program had also secured AGM-22, MGM-51, and BGM-71 missiles and a 20mm cannon for potential tests by the time the program ended.

In August 1968, the US Navy also funded a reliability enhancement program for the QH-50D, ostensibly in support of Nite Gazelle. The 1200-hour reliability program identified the need for reliability improvements in the flight control system, power train/propulsion system, command and control avionics, and payload subsystems. Subsequent improvements were made to the flight control systems, power train/propulsion systems, command and control avionics, controller aids, and controller sensor installations on all QH-50D aircraft. As a result of ARPA's work with the platform, ARPA-ASO also initiated the development of a 24-foot rotor system for modified QH-50D helicopters, with the resulting vehicle being termed QH-50D-2. This vehicle, with its increased lift capability, offered markedly improved payload-range-endurance performance. The increase in rotor diameter would appear to have been a relatively minor development program. The limited radius of action and target area dwell time of the 20-foot rotor vehicle emphasized the need for the 24-foot rotor vehicle. The 24-foot rotor vehicle was capable of 6-hour missions with any of the developed sensor/weapon systems.

Initial weapons tests, involving the test firing of a mounted Minigun and the test dropping of iron bombs at Patuxent River NATC during February-March 1969 were unsuccessful. Consistent accuracy was found to be unattainable through the inertial system then used. A "Walk-up Mode" mudification was proposed in November 1969. This would permit the automatic positioning of the vehicle directly over the target for precise weapon/sensor delivery. The 'Walk-up Mode" modification contract was initiated on 6 February 1970.

The complete modifications and flight testing of Nite Gazelle platforms, and Nite Gazelle platforms with sensors or sensor/weapons systems were accomplished over a 4 to 5-year period. ARPA's activities with the Nite Gazelle program ceased in June 1972. At that time the ARPA-supported program had accomplished a research and development demonstration of the Nite Gazelle concept with the following standoff interdiction weapon systems: LARS, hypervelocity gun, bomblet dispenser, and grenade launcher. Also completed were research and development demonstrations of extending the operating range of the platform by use of the Grandview elevated relay and the Egyptian Goose elevated MTI radar. The Nite Gazelle program proved the feasibility of the basic concepts. However, the test phase was limited and high system performance was not always demonstrated.

After the end of the ARPA tests, the Army conducted follow-on activities with Nite Gazelle vehicles independant of ARPA. Standoff sensor systems, consisting of 2 Blow-Low vehicles (fitted with the LARS), 2 MTI radar vehicles, and one spare vehicle, had been transferred to the Army on 11 December 1970. Further NITE GAZELLE assets were transferred to the Army in February 1972. This included a number of transfers to specific Army elements. Eight Nite Gazelle vehicles with associated electronics including day TV cameras, 2 control vans, and 2 maintenance vans were provided to Army Electronics Command (TACOM). One Nite Gazelle vehicle was provided to the Army Security Agency's Electronic Sensor Laboratory. One control van and one maintenance van were provided to the Army Aviation Command.

Seven modified QH-50D's were scheduled to have been transferred to US Air Force Systems Command/Tactical Air Command, but the transfer was rejected in May 1971. The US Air Force also rejected the transfer of the Egyptian Goose and Grandview systems, with some of the equipment then being put into storage. As of July 1975, 3 Nite Gazelle vehicles in various states of repair are at Gyrodyne's Long Island, New York plant. ARPA also reported that the US Navy, which had phased out the QH-50 family, retained some 300 spare unmodified aircraft in storage in Arizona, which could be used for further projects.