Chapter 1

USAF Enters the Field

A new approach to ARDF, sponsored by Gen. Curtis E. LeMay, when he was Air Force Chief of Staff, brought the U.S. Air Force into the field. In April 1962, General LeMay noted that existing radio devices, such as the OMNI system, gave instant, ambiguos bearings to a station or transmitter. Why, he asked, might not the station be located by a reverse application of the electronic principles involved.

The first of two Air Force attempts to develop a new ARDF system quickly followed. Know as HILO HATTIE, this first project in 1962 was unsuccessful. Its Vietnam test occurred in a C-54 flying out of Tan Son Nhut Air Base, Saigon. The lack of maneuverability of the C-54, problems with the new ARDF system, and difficulties with the U.S. Army agency supporting HILO HATTIE were key factors in the failure.

The second, and utlimately successful, project began as a joint effort with the U.S. Navy, under the title MONA HI. In August 1962, the Air Force assumed entire responsibility for the project, under the nickname, HAWH EYE. Sanders Associatess of Hashua, New Hampshire, developed a new ARDF device, the AR/ARD-18, later the AN/ALR-34, which used Phase Angle Discrimination (PAD) to obtain, without human judgment, the angle measurements on an incoming radio signal in one second. To aid the ARDF crew to pinpoint its location, the Air Force purchased a commercial version of a Bendix Doppler system.

Between February and July 1964, a C-47 deployed to RVN as the test vehicle for the new system. Results were unsatisfactory and the HAWK EYE aircraft was returned to CONUS for further modification. Another round of tests in Vietnam started on the last day of October 1965 and paid some dividends. The most notable HAWK EYE achievement in these tests came on 13 December 1965, when its crew fixed a VC battaliaon within a few hundred meters of its location near the Michelin Plantation. This, and other successes, prompted MACV and 7AF to keep the aircraft in RVN beyond its original 120-day testing period.

Air Force interest in the possibilities of ARDF was not confined only to the Chief of Staff level. In particular, an Air Force officer, Col. James S. Novy, on assignment to National Security Agency (NSA), made vigorous efforts to arouse USAF interest in its potential. In Janurary 1964, a month before the first HAWK EYE test in Vietnam, Hq PACAF had submitted a Qualitative Operational Requirement for seven HAWK EYE aircraft with an HF Direction Finding System. The Air Staff, however, delayed approval of the requirement, until the first HAWK EYE aircraft had proved its worth.