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DZ Considerations

DZ Considerations
with input from
U.S. Army Combat Readiness/Safety Center
Fort Rucker, Ala.

(Editor’s note: This article is an individual’s experience as a drop zone safety officer. While the information contained in this article is correct, it’s not a complete compilation of duties and requirements as prescribed in Field Manual 3-21.220, Static Line Parachuting Techniques and Training. Before participating in an airborne mission, refer to FM 3-21.220 for all of the requirements.)

During my 20 years as a jumpmaster, the situation often arose where a drop zone safety officer assignment was made at the last minute. In a reserve component unit, there were many reasons last-minute assignments were made, such as someone was attending an Army school instead of drill, there were other priorities and the list goes on. Regardless, airborne operations still needed to happen. While all jumpmasters strive to maintain currency, some are more proficient at DZ operations. I hope to provide some of my observations and concerns. The following narrative assumes an airborne mission occurs in an Army-run DZ.

Planning and Deploying
A DZ survey, AF IMT 3823, is required for airborne operations. Once you’re tapped to be the DZSO, get a copy of the airborne operation order and DZ survey as soon as possible. Be sure to attend the airborne mission brief. When you know the plan, gather the support personnel and equipment outlined in Field Manual 3-21.220, Static Line Parachuting Techniques and Training. It’s important to get a sufficient number of support personnel assigned to the DZ party. Ensure all personnel know the timeline for operations. Make sure you read and understand the DZSO duties and responsibilities. Take copies of FM 3-21.220, unit standard operating procedures, after-action review forms and any other reference materials with you on the day of the mission. Be sure to conduct a risk assessment and ensure coordination with the airborne commander is completed.

The medic and medevac vehicle driver need to take care of the medical equipment and vehicle. They should also have a map of the route from the DZ to the nearest treatment facility, and it’s imperative they have a solid medevac plan. If time is available before the jump, the ground medevac plan should be rehearsed and timed. The rehearsal should occur during the same time window of the jump to gauge traffic density and other conditions.

The radio-telephone operator needs to gather the radios and spare batteries. The radio requirements will be Mission, Enemy, Terrain and Weather, Troops and Support Available, Time Available Civil Consideration, or METT-TC, dependant, but I recommend at least three radios. The RTO should test the radios, using all the frequencies assigned to the airborne mission. There needs to be a primary and alternate means of communication — internal and external — facilitating communication between the DZSO, the malfunction control officer, range operations, medics, departing airfield control officer, emergency services, life flight, the local power company (if power lines are present) and other local agencies as needed.

I suggest having at least two additional personnel for DZ support. These personnel can help you inventory and inspect the DZ kit. The kit should have an inventory list. If it doesn’t, refer to FM 3-21.220 for the required items. Perform preventive maintenance checks and services on all equipment. Inspect the helium gas bottle using the gas valve with pressure meter. The gas bottle needs to be at least half full. You need enough gas to release at least two balloons from the DZ. In FM 3-21.220, there’s a list of approved anemometers to be used for measuring winds. Leave home station so you arrive at the DZ four hours prior to time on target of the first pass.

Activities on the DZ
Upon arrival at the DZ, walk or drive around to inspect the terrain surface, checking for hazards on and near the DZ as prescribed in FM 3-21.220. Compare what you observe during your inspection with the information listed in block 11 of the DZ diagram on the DZ survey. You need to verify the information and contact the DACO to report any information not listed on the survey. Place a radio with the medics in the medevac vehicle location. Place another radio at the center of the DZ. During your DZ walk around, you can conduct radio checks.

The next step is to release a pilot balloon, or PI BAL, to determine the mean effective winds. Take the time to train inexperienced support personnel; teach them how to inflate the balloon, run the stopwatch, take the balloon direction, measure the balloon elevation angle and observe the balloon. Release the PI BAL and determine the MEW. Use this information to calculate the wind drift using the D = KAV formula. [D = distance in meters. K = constant (drift in meters per 1,000-foot loss of altitude in a 1-knot wind). A = altitude in thousands of feet. V = average wind speed (velocity)]. Normally, it’s best to use the PI listed on the DZ survey. However, you need to check FM 3-21.220 for specific PI location for the type of aircraft flying and the DZ.

Train one of the support personnel to take surface wind readings and wind direction, and then transcribe the readings into a logbook. This Soldier can act as a recorder of information during the drop. Walk off the wind drift distance and the forward throw distance to determine the release point. This will be a temporary RP location. Also train the support personnel how to lay out the code letter using the VS-17 signal panel.

Ninety minutes prior to the first drop TOT, release a second PI BAL and determine the MEW. Recalculate wind drift for the RP location and move to the new RP location. Lay out the code letter using the signal panels. The DZ must be established no later than one hour prior to TOT. The RTO needs to begin constant monitoring of the aircraft primary and secondary frequencies. Once communication is established with the aircraft, the drop can begin. Contact the pilot to state drop altitude, drop speed, number jumpers on board and the drop heading. Advise the pilot of the DZ wind speed and direction. After each pass, let the pilot know how many parachutists exited the aircraft.

Post Activities
Give the aircraft crew a strike report in accordance with FM 3-21.220 for each pass. Once the drop is complete, contact the aircraft via radio and thank the aircrew. This simple act will build a good relationship for later airborne missions. Don’t begin to tear down until all personnel and equipment are accounted for. Ensure the RTO collects the radios and tears them down. The medics need to pack up any medical equipment and prepare for follow-on tasks. The support personnel can tear down and pack up the signal panels. You will need this information for the airborne AAR you’ll send to higher headquarters. Complete the AAR form using the notes taken during the mission. The final task of the mission will be to send the AAR to higher headquarters.

It’s important to take your job seriously when performing the duties of a DZSO. Don’t take the responsibility lightly. Lives depend upon you doing your job thoroughly, by the books and attentively.

  • 1 February 2014
  • Author: Army Safety
  • Number of views: 14530
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