PHYLLIS ANN is Conceived 

In late October, 1965, the HAWKEYE C-47 returned to Vietnam for a projected 120-day trial, presumably having spent the 15 months since it’s last appearance undergoing further modification and testing Stateside. COMUSMACV, meanwhile, expressed a keen interest in ARDF, no doubt the result of the timely SIGINT support upon which operations STARLITE and SILVER BAYONET had been based. In fact, Gen. Westmoreland now reckoned he needed 2,424 hours of ARDF coverage weekly—a nine-fold increase over the current 272 hours being tasked. An initial proposal called for procurement of 79 ASA U-6/U-8 aircraft, since “It does not appear that the C-47 will meet this requirement in a timely manner."

Lt. Gen. Joseph H. Moore, 2d Air Division commander, vigorously objected. He maintained that "Limitations of short range Army aircraft and lack of all-weather capability … point up the need for USAF to enter this special area of aerial reconnaissance as a proper role for USAF." The Air Staff in Washington agreed and, fortunately, HAWKEYE’s performance was now much improved. On 13 December, the crew made a dead-on fix of a VC regiment in the Michelin Plantation north of Saigon. Moore had made his point—MACV requested an extension of HAWKEYE’s 120-day test.

On 11 January 1966, Air Force ARDF plans were outlined in Southeast Asia Operational Requirement (SEAOR) 32-FY-66. A week or so later, during one of the frequent top-level meetings held in Honolulu, COMUSMACV reiterated his needs for increased ARDF support, but now simply asked for “a properly tested and operational system which can be provided in the shortest possible time frame, regardless of the type aircraft or the service providing it.” [Emphasis added.] In fact, USAF wheels had already begun to turn ten days earlier in an urgent conference held at Wright-Patterson AFB, Ohio. Air Force Logistics Command was put in charge of the project, code-named PHYLLIS ANN. In a nutshell, the program called for conversion of 35 C-47 airframes into HAWKEYE-like ARDF platforms. Warner Robbins would again oversee the conversion work, while Sanders Associates geared up to put the ARDF system, now designated AN/ARD-18, into production.



Meanwhile, 2d Air Division pressed for increased and immediate tactical SIGINT support in the form of an airborne platform capable of intercepting enemy radio traffic in the midst of an attack and possibly even serving as a forward air controller (FAC) as the battle progressed. Two Airborne Emergency Reaction Unit (ABERU) aircraft, scheduled for phase-out in Korea, appeared to be ideal candidates. A major stumbling block appeared immediately—USAFSS had very few Vietnamese or Cambodian linguists to begin with, and nearly all were already deployed on other missions. Furthermore, NSA was at best lukewarm about the proposal. Much squabbling ensued among the affected SIGINT parties but ultimately USAFSS took the bull by the horns, announcing that it would configure the aircraft utilizing only its own resources. On 29 October 1965 the project was officially christened DRILL PRESS. As with HAWKEYE, a 120-day in-country test was planned.


The DRILL PRESS birds. (L) Norm Taylor photographed 43-49680 at Mathis Field, San Angelo, TX, before deployment to SEA. The
blue bands may be markings applied for Stateside exercises. (R) The other aircraft, 43-16254, at an unknown location in Vietnam.

The first ABERU C-47 arrived at Yokota (Japan) on 27 December and by 3 January was ready for initial test hops. On 10 January the first familiarization flight was launched out of Tan Son Nhut, to be followed by Phase I testing, a comparison of airborne versus ground site intercepts. The DRILL PRESS results were spectacular, turning up “25 unique or new communications links in each mission, flying two a day.” 

In March, USAFSS conducted off-the-record testing to determine if DRILL PRESS intercepts could be tipped-off for ARDF to the HAWKEYE bird, flying some distance away. Although HAWKEYE could hear the enemy transmitters, signal strength was insufficient for DF “lock on.” The tests were deemed inconclusive, but the C-47 collection-only platform had more than proved its value. DRILL PRESS would remain on station for many months to come.


Project PHYLLIS ANN represented a significant technical—and political—commitment by the USAF which, having made some rather optimistic promises, now found them difficult to keep. Second Air Division in particular was feeling the heat, noting that  “April first delivery of number one aircraft extremely important, with late March arrival considered of utmost advantage as demonstration of Air Force ability to deliver promised product on time. Extreme measures not only justified but necessary.” Headquarters USAF concurred, advising all affected commands that “This program is of the utmost importance to USAF” and required “extraordinary actions by all personnel concerned with the program to meet the deployment date.”

Obtaining the necessary airframes was not an issue. Many C-47s were still in the inventory, and others could be quickly resurrected from storage. The Gooney Bird was not an ideal ARDF platform, but there were plenty of them—and they were all paid for, a major selling point for any proposed system in what was already becoming a very expensive war.

The ARDF system was another matter. HAWKEYE was, at best, a “proof of concept” demonstrator. As originally laid out, the PHYLLIS ANN proposal called for the 35 aircraft to be delivered by August, 1966, but this quickly proved to be unrealistic. Obtaining components then fabricating the AN/ARD-18 ARDF sets would be a daunting task for both Sanders Associates and the USAF organizations tasked with making it happen. 

New Mission, New Organizations

As engineers struggled with development and production of the ARD-18, HQ USAF began to put in place the infrastructure necessary to provide ARDF support in the war zone. On 28 March, coincident with the rapid build-up of U.S. ground forces in Vietnam, a new top-level air command—Seventh Air Force—was established, replacing 2d Air Division. Among the Seventh’s component units was the 460th Tactical Reconnaissance Wing (TRW), which itself had been organized at Tan Son Nhut only ten days earlier.

To maintain and operate the anticipated PHYLLIS ANN fleet, two new squadrons, the 360th Reconnaissance Squadron (RS) at Tan Son Nhut and the 361st RS at Nha Trang, were activated under the 460th TRW. A third squadron, not yet activated, was programmed for Pleiku. Operators to man the “back end” ARDF equipment would be furnished by the SIGINT-cleared members of USAFSS’s 6994th Security Squadron, activated at Tan Son Nhut on 15 April. Detachments would be formed as required to support the mission at other bases. The 6994th was under the nominal control of the 6922d Security Wing at Clark AB, Philippines, but for practical purposes the Air Force ARDF mission would be tasked by MACV.

By mid-April, the Air Force had its ARDF organizational structure in place, although all units were short of men and even such basic needs as tables and chairs. Worse yet, HAWKEYE and the two DRILL PRESS aircraft were the only airplanes available to fly. The first RC-47, as the ARDF Gooney Birds would initially be designated, would not arrive for another month.

Article by Joe Martin
7 April 2016 

NEXT: PHYLLIS ANN Makes Her Entrance