How to Prep a Landing Zone

One of the primary tasks of the artillery in combat is the firing of preparations for a heliborne assault. The purpose of the 'prep' is to destroy or neutralise the enemy and his defences in the vicinity of the landing zone and to suppress antiaircraft fire.

The prep should be intense, cover the entire threat area, and be as brief as possible for accomplishment of the mission. The latter is a critical factor in achieving surprise and limiting the enemy reaction time. The prep must be continuous and must be shifted from the landing zone just before the initial assault elements touch down. A variety of procedures are followed in coordinating prep fires. One procedure that has proved to be very effective is discussed in the example below.

The Problem and Mission

The landing zone is typical - a clearing in the jungle containing rice paddies and overgrown cultivated fields (Fig. 1). The infantry commander desires a 20-minute artillery and air preparation with emphasis on the bunkers and trench system that have been reported to be in the tree line to the southwest side and the northwest corner of the landing zone. The prep is also designed to suppress possible antiaircraft fire. Due to prevailing winds and the landing zone orientation, the troopships will approach from the northwest and exit to the southeast.

Fire Support

Two airstrikes are available. Each airstrike will consist of three sorties armed with conventional bombs, cluster bombs and napalm. Two 105-mm howitzer batteries, one 155-mm howitzer battery, and one 8-inch howitzer battery are within range. The artillery positions are to the south of the landing zone.

Control

An air observer has been assigned by division artillery to adjust the fires and the artillery liaison officer will be airborne with the infantry commander to provide a command and control link with the assaulting element. The air liaison officer (ALO) and the infantry S3 will also be in the command and control ship. In addition, an observation helicopter has been made available for the direct support (DS) artillery battalion commander.

Planning

The initial step in planning is an aerial reconnaissance of the landing zone by the by the artillery battalion commander or S3. If aerial reconnaissance is not possible, aerial photo or map reconnaissance should be made from the new series of pictomaps.

Coordination between the artillery liaison officer and the air liaison officer establishes the artillery-tactical air , fire coordination line along and parallel to, the tree line on the northeast side of the landing zone. This will allow the artillery to fire to the southwest of this line without endangering the tactical bombers. The aircraft can make bombing runs along the northwest-to-southwest path without being endangered by artillery shells. The airstrikes will consist of bombing runs along the known north-eastern bunker locations and runs along and inside the tree line bordering the landing zone. These airstrikes and the artillery prep discussed below will be occurring at the same time.

To provide better coverage of the hard targets and jungle area a fuze mix of 50% delay is normally used.

Before the mission the air observer and fire units are briefed on the following points:

• The fires of the 8-inch howitzer battery are to be shifted by using 50-meter and 100-meter shifts to thoroughly cover the area of suspected bunkers and trenches at the west end of the landing zone.
• The fires of the 155-mm howitzer battery are to be moved by using 50-meter and 100-meter shifts to saturate the heavier jungle west of the landing zone from the tree line to a depth of approximately 300-meters.
• The fires of the two 105-mm howitzer batteries are to be moved by using 50-meter shifts to saturate the tree line (overlapping the coverage of the 155-mm and 8-inch howitzers) to a depth of 150-meters. The 105-mm fires should be moved to the ends of the landing zone and then out to a depth of 400-meters along the troop helicopter and approach and departure flight paths (in the vicinity of areas A and B, Fig. 1). These areas should be receiving fire just prior to the helicopter assault to suppress antiaircraft fire.
• The air observer, DS battalion FDC, and all fire units will operate on one fire net with a minimum number of transmissions. Batteries will announce only the call sign and SPLASH for the initial rounds in each fire for effect (FFE). For example, assume that Battery A computes corrections and fires battery four rounds in FFE with the new data. The battery computes the time of flight and announces ALFA, SPLASH, 5 seconds prior to the impact of the first of the four volleys. The observers attention will be directed to the Battery A impact point by the announcement of ALFA, SPLASH. The observer will spot the first round and then announce the corrections to Battery A to move the fires to cover the next desired area. Battery A will read back the corrections. If the Battery A read-back is correct, the next transmission between battery A and the observer will be ALFA, SPLASH on the next FFE and the observer will be free to direct his attention to the other fire units. A simple transmission is as follows:
• Battery A: ALFA, SPLASH
• Observer: ALFA, LEFT 50, REPEAT, REPEAT
• Battery A: ALFA, LEFT 50, REPEAT, REPEAT, OUT

It is imperative that this abbreviated radio procedure be utilised. It permits the necessary and accurate exchange of information between the observer and the fire units in the least possible time and with the least confusion. The first REPEAT requests the same range to be fired. The second REPEAT refers to fire for effect.

Conduct of the Prep

A thorough briefing and a competent air observer are critical factors in the success of the prep. Once the firing starts, it is the observer who 'moves' the artillery to provide the desired coverage. The DS battalion FDC controls the prep, but it relies on the observer to implement the plan. The artillery battalion commander and the infantry commander (through the artillery liaison officer) mat request more thorough coverage of a particular area by contacting the DS battalion FDC on another communication net, such as the battalion command fire frequency. The DS battalion FDC controls and monitors the entire prep and aids the observer by passing on requests from the infantry commander and other observers.

The prep is started with a countdown from the DS artillery battalion for a time-on-target (TOT) mission for all firing units. Before the countdown is initiated, a check is made with the artillery liaison officer to insure that the helicopters and airstrikes are on schedule. Once the firing has started, the observer adjusts the artillery in accordance with his briefing and advice from the infantry and artillery commanders.

While the helicopters are landing and the infantry is making initial deployments, the 155-mm howitzer battery and one 105-mm howitzer battery execute blocking fires on targets UB4004 and UB4005 to prevent enemy reinforcements from reaching the LZ and to prevent wounded and disorganised enemy troops from escaping. The other 105-mm howitzer battery and the 8-inch howitzer battery are kept on call to provide support for the deploying infantry.

The shift to blocking fires is coordinated with the artillery liaison officer, the ALO, and the infantry commander so that the helicopters touch down less than 2 minutes after the battalion FDC gives the command to shift two batteries to blocking positions and announces END OF MISSION for the two 'on-call' batteries. All fire units immediately report "tubes clear" on LZ area to confirm that it is safe for the helicopters to approach.

Characteristics of the Prep

The prep described above has the following characteristics:

• It is simple and therefore easy to control, and it can be planned in a very short time; in an emergency the observer can be briefed after he is airborne.
• It has maximum flexibility and therefore can be adjusted to fit many different situations. If fewer fire units are available, the rate of fire can be increased up to a recommended maximum of battery 6 rounds for the 105-mm battery, battery 4 rounds for the 155-mm battery, and battery 3 rounds for the 8-inch battery.
• It puts the maximum amount of 'steel' in the target area. The ammunition expenditure for the prep described above would be approximately 760 rounds by the 105-mm weapons, 190 rounds by the 155-mm weapons and 70 rounds by the 8-inch weapons.
• It has the advantage of surprise. Registration is not necessary (although it would be helpful; the observer adjusts the fire to cover the required area.
• It is intense and continuous, with fires shifted from the LZ less than 2 minutes before the troopships touch down.
• It is integrated with air and therefore does not require that artillery cease fire for airstrikes.

Summary

As previously stated, the key to the success of the entire operation is a thoroughly briefed and competent air observer. A good observer can control from 4 to 6 units firing into the same general area. The system has been successfully used with many variations, such as using three observers to control 12 firing units (on three separate nets) to saturate a large area with artillery in a short period of time. Another variation which has been employed is the use of three observers (on three nets) and nine fire units to concurrently prep six separate company-size LZ's in 8 minutes. Application of the principles of simplicity, flexibility, and maximum firepower in the manner described above will result in a successful prep each time.