US Army in Vietnam - Eagle Flight Operations Techniques of Planning and Employment


Factors in Planning a Landing

Experience was to show that several factors had to be considered in planning for a landing. The planning had to be accomplished almost immediately upon arrival over the selected target area since the enemy would already have commenced to react to the presence of the attacking force. Consequently, planning, decision making, and the communication of those decisions in the form of instructions to the force and it's supporting elements had to be almost simultaneous.

The following are some of the factors which had to be considered by the Eagle Force commander;

1. In the case of suspected personnel, it was necessary to determine if they actually were enemy forces since there existed every possibility for mistaking Vietnamese friendly forces, armed and dressed in black or nondescript uniforms, for Viet Cong. Lack of communication and a positive means of identification often compounded this problem. However, it was also the case that invariably if the suspected personnel were enemy then this would be confirmed by their running, attempting to hide or firing at the helicopters. 


Care had to be taken in selecting the LZ especially when the target was located in close proximity to heavy vegetation so as to minimise the possibility of landing in a preplanned ambush based on hidden enemy forces.


The commander was required to consider whether the enemy force was massed or scattered, organised to fight or disorganised and in flight. His decisions regarding the use of pre-assault airstrikes, choice of landing formation and the selection of a suitable LZ were all affected by the answers to these questions.


If the logical target was bisected by a canal or similar terrain feature then the choice of landing formation, selection of LZ's and decisions regarding the capability of a split force against the enemy had to be considered.

Techniques of Target Designation

The use of compass and clock directions in orally describing a target and landing zone was almost mandatory since in an area dense with canals and groves the mere reference to a single canal would be meaningless. A typical landing instruction to the helicopter leader might be,

" ....The canal running from NE to SW about 500 meters out on our 2 o'clock position is the baseline, do you see it? At 3 o'clock on the base line, a small clump of trees on the canal is the center of mass, can you identify it? land numbers one and two on the NW side and numbers three and four on the SE. Keep both sections 300 meters out from the canal.... "

The target could also be identified by marking it with tracer or smoke grenades and by vectoring helicopters over the target by pilots of other aircraft who have observed it.

Flight Formations



Landing Formations

Commanders had a wide range of choices regarding landing formations and selection was based on the nature and size of the target and the terrain features within the target area. Some of the formations used were as follows;

To assault against enemy forces in groups of up to 50, disorganised and in the open, and depending on how heavily they were armed, a landing formation known as the 'half box' was chosen. It provided a '3 o'clock exit' for all troops, thus eliminating the necessity for any troops to move around the helicopters before assaulting. the enemy were caught between the two lines of assaulting forces.


To screen a large open area following an air strike, or to search for an enemy who was hiding, the Eagle Force troop carrying helicopters would land in a line formation, with about 100-meters seperation between helicopters.

To attack a large enemy force reported to be in dense vegetation the helicopters would be landed in line formation about 300-meters away from the objective. A closer landing could possibly have placed the force in an enemy ambush. If the enemy force was reported to be small, the helicopters would be landed in line much closer to the enemy in order to prevent him from escaping before the assault could take place. As the troops attacked the near side of the tree line the armed escorts make attack passes on the far side in order to restrict the enemy from retreating (fig 1).

Fig 1

Fig 2

In order to trap an enemy force hiding in groves along the banks of a canal, the 'open box' landing formation could be used. Two aircraft landed on either side of the canal forming a box roughly 300-meters on a side. squads would assault and direct their fires at the enclosed target (fig 2).

Execution of Assault

Once a commander had selected his target and decided upon his landing formation and plan of assault, he had to communicate his decisions to the helicopter pilots and the armed escort helicopter flight leader.

Generally a lack of time would not permit the prior briefing of each squad in helicopters 2, 3, and 4. Since the forces are not thoroughly briefed on either the landing formation or the assault plan, unless ground winds absolutely prohibited it the pilots  would attempt to land in a direction which provided the troops a 3 o'clock exit from the aircraft toward the objective. Sometimes the crew chief of the helicopter would indicate to the soldiers the direction of the objective as it would appear to them as they emerged from the helicopter.

Immediately upon landing, squads were rapidly assembled and the commander and his squad leaders would quickly take control. radio contact with the orbiting empty helicopters, the armed escort helicopters and the O-1 observation aircraft were immediately established and situation reports passed to higher headquarters.

Once on the objective, the troops would work rapidly to screen the area, kill or capture the enemy, apprehend suspects and then prepare to reload. Since an Eagle Force was considered to be more effective when airborne and in a position to attack, excessive time was not spent on the ground following the assault or capture of the enemy. If a more lucrative target was reported to the empty orbiting helicopters by other units then a red smoke grenade or some such pre-arranged signal would be dropped to indicate to the commander that the troops should be organised for extraction.

Reloading the Force

Upon completion of the ground action the commander would study the area and determine the disposition of his squads. he was responsible for insuring that the area was secure before the helicopters came in to land. If the terrain permitted it, the troops would be formed up in column of squads, approximately 30-meters between squads, with the last squad up-wind. However, if a squad was widely separated from the rest of the force, possibly seperated by a canal or other terrain feature, it could be reloaded in place, provided that a suitable LZ was available.

The commander would contact the helicopter flight leader  and inform him of the wind direction and identify the LZ. It was Standard operating Procedure that should radio communications fail, then the formation of troops in line of squads was a visual cue that the area was secure and that the force was ready to reload. Each squad had a colour code (indicated by a scarf or piece of cloth worn on their uniforms) and each helicopter was designated by a corresponding colour code  and thus identification for pickup and reloading was simplified.

Whilst awaiting the return of the helicopters and during all loading operations, each squad would maintain close security of the area whilst the armed escorts continued to orbit and protect both the troop helicopters and the troops themselves during the course of the reloading operation.

Reloading was done while the helicopters maintained partial power. If the helicopter was carrying nearly a full fuel load, or if prisoners aboard caused the load to exceed twelve men (all passenger seats are removed from the cargo compartment), it required an obstacle clear distance of about 900 meters in an up-wind direction for takeoff. each helicopter would take off as soon as loaded in order to minimise time on the ground, a period of great vulnerability.



US Army Military Assistance Advisory Group Vietnam (MAAG) - Lessons Learned No. 32 Eagle Flight Operations (October 1963)





Retrieved by Memoweb from at 25/08/01