Project CHECO


This document endeavors to follow the chronological changes in the principal rules of engagement-covering U.S. air operations in Southeast Asia from their beginnings through 1965. The introduction carries the situation rather swiftly to 24 November 1962, at which time the MACV Directive No. 62 established definitive operational restrictions on U.S. aircraft to be employed on combat support missions. As the situation grew more complex, additional missions were conceived and initiated to cope with operational requirements. As the reader may or may not be familiar with the nature and scope of these missions,their nicknames, purpose and general area are as follows:

ABLE MABLE: A reconnaissance task force which flew the original YANKEE TEAM missions in Laos, commencing May 1964.

BANGO/WHIPLASH: Close air support and rapid response strike aircraft operating in Laos from July 1965. BANGO-F4C aircraft; WHIPLASH- F105's. 

BARREL ROLL: Interdiction missions, initially in east Laos, commencing December 1964. Southern area later preempted by STEEL TIGER.

BARREL ROLL limited to Laotian panhandle.

FARM GATE: A covert strike operation whose overt mission was the training of VNAF personnel beginning in December 1961. It replaced the short- lived JUNGLE JIM operation.

FLAMING DART: Retaliatory strikes in NVN following the Gulf of Tonkin incidents of August 1965.

JUNGLE JIM: Original covert training and reconnaissance operations in NVN during November 1961.

MULE TRAIN: Logistic air support in South Vietnam.

RANCH HAND: Defoliation operations in South Vietnam.

ROLLING THUNDER: Followed FLAMING DART in strike missions against North Vietnam commencing March 1965.

STEEL TIGER: Interdiction missions in the Laotian panhandle south of Nape Pass. Initiated April 1965.

TIGER HOUND: Armed recon and interdiction; a division of the STEEL TIGER area to include south- east Laos south of the 17th Parallel.

YANKEE TEAM: Reconnaissance. Laos, from May 1964.


In a futile attempt to reverse the course of events engulfing the French in Indochina, the U.S. Air Force contributed 1,800 airlift sorties, comprising 13,000 flying hours, during the first six months of 1954. On 7 May 1954, Dien Bien Phu fell to the Communist Viet Minh, followed on 20 July by the Geneva Convention on the partition of Vietnam. The U.S. decision to pledge increased aid to the government in South Vietnam was made by Presidential announcement of 24 October 1954. Thus began the role which the U.S. Air Force was to play in counter-insurgency within the overall framework of U.S. foreign policy as supplemented by the policies of the Department of Defense.

By spring of 1960, the counter-insurgency situation in RVN had ob- viously deteriorated. With the arrival of the first of the U.S. Special Forces Teams on 30 May, RVN resistance stiffened. This month also marked the delivery of the first full squadron of 25 A-IH aircraft to the RVN. Later, on I October 1961, PACAF deployed a Control and Reporting Post(CRP) to Tan Son Nhut Air Base:

Its purpose was to provide radar coverage for the southern area of SVN and to train the Vietnamese Air Force in controlling air traffic, both civil and mili- tary. Within four months, 63 Vietnamese personnel had been trained, the CRP was expanded into a CRC, and it became part of the Tactical Air Control System which was established in mid-January.

The JCS, on 14 November 1961, directed JUNGLE JIM forces to be deployed to the RVN. This deployment consisted of the 1st Air Commando Group (formerly the 4400th CCTS), four SC-47's, four RB-26's, and eight T-28's -- all carrying RVN Air Force (VNAF) markings. Within 48 hours, President Kennedy announced the decision to bolster RVN strength but not to commit U.S. combat forces. On 11 December, two U.S. Army helicopter companies arrived in RVN.

The commitment, by the United States, to a policy of unlimited support of the RVN, short of actual combat forces, was subject to many restraining influences. In addition to the provisions of the Geneva Accords of 1954, which the U.S.,although not a signatory, had undertaken to support, there were other considerations - the possible alienation of the Vietnamese people; relations with Cambodia, Laos, and Thailand; and vulnerability to charges, by the NVN and Communist China, of aggression in Southeast Asia. Further, and of particular significance to the U.S. A.-my and Air Force, was the opinion of Mr. McNamara (December 1961) that the war in South Vietnam should be considered a ground war and that although "naval-and air support operations are desirable, they won't be too effective..." The U.S. military structure in the RVN and the ensuing intra-command relationships reflected an awareness of McNamara's views.

Two short quotations from the Geneva Accords of 1954 serve to illus- trate the nature and scope of the constraints imposed. Chapter III, Article 16 (quoted in part): "With effect from the date of entry into force of the present Agreement, the introduction into Vietnam of any troop reinforcements and additional'military personnel is prohibited." Chapter III, Article 17 (a): "With effect from the date of entry into force of the present Agreement, the introduction into Vietnam of any reinforcements in the form of all types of arms, munitions and other war material, such as combat aircraft, naval craft, pieces or ordnance, jet engines and jet weapons and armored vehicles, is prohibited."

Thus, the U.S. decision to increase substantially its aid to the RVN ran head on into the Geneva Accords and the International Control Committee(ICC) established to oversee its provisions.

On 28 October 1961, Secretary of State Rusk sent a message to the American Embassy in Saigon requesting concurrence on ground rules for the introduction of the USAF JUNGLE JIM unit into the RVN. Mr. Rusk proposed that the aircraft have Vietnamese markings painted on them before being flown in or being brought in by surface transportation. Military personnel, other than aircrews, were to arrive in the RVN in civilian clothes but could then wear their uniforms. Such were some of the efforts to circumvent the provisions of the Geneva Accords and the ICC.

This issue was finally settled on 16 November 1961 when President Kennedy formally announced the U.S. decision to aid the Government of Vietnam - short of introducing U.S. combat forces. The position that U.S. combat forces were not involved in the war was to be maintained for the ensuing two years (until 31 December 1963).

By the close of 1961, the Communist insurgency in South Vietnam had grown to proportions where immediate response was required to contain and then defeat the threat. This situation resulted in a modification of our Policy Position to provide for U.S. armed and manned helicopters to 'defend themselves" and to return fire from the ground. (Subsequently, authority was granted to initiate fire on known Viet Cong targets posing a threat.)

The immediate U.S. objective, at this time, was to provide the VNAF with such training as would eventually enable the Vietnamese to perform all required missions. Determined to meet this goal and to realize the "immediate response" requirement, PACAF conceived the covert FARM GATE operation. Following CINCPAC approval, the first of these missions was flown in December 1961.

The concept of employment of FARM GATE (previously JUNGLE JIM) was to utilize the function of training the VNAF as a cover. The aircraft and personnel of Detachment 2, 4400th CCTS to actually be used in support of RVNAF actions against the Viet Cong within the borders of the RVN.

The concept envisioned, "all feasible operational activity," overt and covert, and would be in addition to the advisory and training functions.

In agreeing with the FARM GATE concept, CINCPAC said:

.... In addition (to operational tests and combat Support flights previously authorized by JCS and CINCPAC to train the VNAF), as decided at the SecDef meeting 16 December, all kinds of conventional combat and combat support flights can be flown in SVN by Detachment 2, 4400th CCTS provided a Vietnamese is on board for purpose of receiving combat support training.

This was amplified on 26 December when the JCS said that FARM GATE aircraft could be employed on combat missions only when the VNAF did not have the capability. This latest instruction also said that combat training missions with joint crews would be conducted so the Vietnamese crews could take over the missions at the earliest possible time. The rules dictated that the aircraft be based in-country and be of the same type as the host country, if the effort was to be plausibly deniable. These latter dictates had been a continuing limiting factor on FARM GATE operations in the RVN.

The issue of U.S. pilots flying FARM GATE missions in the RVN came to the fore early in 1962. Admiral Felt's opinion of the State Department release of 9 March 1962 was that it evaded the issue. lie recommend, instead, a "factual" statement:

USAF pilots are flying in two-seater T-28's and RB-26's with VNAF pilots. The purpose of these missions is to train VNAF pilots in tactical air strikes. On some of thesetraining sorties, the aircraft deliver ord- nance on actual Viet Cong targets. No USAF pilot has ever flown on a tactical mission except in the role of tactical instructor, and VNAF pilots flying single-seater AD-6's (A-lH's) continue to perform most of the combat air sorties.

In a message to the Embassy in Saigon in February 1963, State expressed the obvious and unequivocal position that the FARM GATE activity in the RVN was a "clear violation of the Geneva Accords."

The VNAF had no rules of engagement in late 1961 except to avoid overflying the boundaries of neighboring countries. Once an air Strike was approved by the AOC or higher authority, the pilot was free to strike the target. Neither were there rules of engagement for air defense. Upon being advised of this, CINCPAC suggested to CHHAAG-V that the VNAF be assisted, if they so desired, in developing rules of engagement - initially for air defense. Admiral Felt then proposed guidelines for the interception, identification, and destruction of hostile aircraft intruding into the airspace of the RVN. VNAF accepted the suggestion-and drafted rules of engagement. By late April 1962, the Joint General Staff (JGS) had approved them and was in the process of coordinating them with other governmental agencies.