Troubleshooting the gunnery solution--a leader STX.

Field Manual 6-40 Field Artillery Manual Cannon Gunnery has been recognized widely by the Army and Marine Corps as the training publication with clear and uncontested truth about meeting the requirements for accurate predicted fires. Surprisingly though, this manual (last updated as a multi-service manual in October 1999) tells Field Artillery leaders nothing about how to troubleshoot problems in firing accuracy.

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As the adage that "no plan survives first contact with the enemy" is true, so also is that "no firing battery always hits the target." The need to isolate, detect and solve firing inaccuracies by practicing a gunnery troubleshooting discipline is an absolute imperative for FA and fire support professionals.

For several years now, the Field Artillery School at Fort Sill, Oklahoma, has been teaching troubleshooting methods in the classroom. These methods are "math drills" to capture database errors or correctly compute an answer, given some formulas on a dry-erase board. It has proven useful for students who are keenly attuned to manual gunnery procedures from recent experience but not for those out of practice.

However, Field Artillerymen have been returning to the FA Captain's Career Course (FACCC) and other professional military education (PME) courses, such as the FA Pre-Command Course (PCC), in large numbers with little or no recent live-firing experience. The need to "refresh" through practical exercise and live fire is paramount.

"Reset" of Field Artillerymen. Recognizing this atrophy in core FA competencies, such as gunnery, the Commandant of the Field Artillery School identified Reset ("Re-Red" Artillerymen) as his highest priority. The FA School now is implementing initiatives to help Reset basic leader FA skills in officer and NCO career courses.

Correcting this "skill-atrophy" trend only may require minor alteration of the methods and types of instruction at Fort Sill. Considerable thought also has been given to adding live fire and more field training back into selected sections of these courses to address the degradation in supervisory gunnery skills. Hence, the 428th FA Brigade (until recently Fort Sill's school brigade, known as the 30th FA Regiment) began an experiment in October of 2006 with PCC--a situational training exercise (STX) for gunnery troubleshooting.

Gunnery Troubleshooting STX. PCC prepares FA lieutenant colonels and colonels for positions as battalion and brigade commanders. In most cases, these leaders are the senior FA officers responsible for FA live-fire certification, safety and skill proficiency. Not surprisingly, many have been conducting full-spectrum operations and, for the most part, have not been conducting traditional FA and (or) fire support during the current War on Terrorism (WOT).

They require (and desire) an opportunity to review the five requirements for accurate predicted fires, but more importantly, an opportunity to ensure they can train their units to meet them.

The STX presents exactly what these leaders need in Reset--an opportunity to observe, detect and correct firing inaccuracies. This troubleshooting field STX is an efficient and visual way to hone supervisory skills that have remained dormant and unpracticed.

The STX is suited ideally for the future battery commanders attending the career course. This 90-minute module is nothing more than the classroom gunnery troubleshooting lesson taken to the field. The simple beauty of it is that each mission fired provides an opportunity to reinforce the causes of inaccuracies and troubleshoot the errors, detecting and isolating the cause of the errors, while observing and inspecting all elements of the gunnery team. See Figure 1 for questions supervisors ask to detect and isolate the causes of gunnery errors.

Coaching and mentoring how to train on solving the gunnery solution is a perishable skill. Practice with live rounds or simulation refreshes this skill. Further, few would question how critical it is that senior FA leaders understand this discipline to ensure it continues correctly in their units at all levels. Although a review of FM 6-40 and a few PowerPoint slides present a nice academic recap of principles, there is no substitute for actual (or simulated) firing to properly reinforce FA gunnery--for FA commanders, FA NCO supervisors, fire support officers (FSO) and others.

The concept for this STX is simple. In a field environment, students observe firing inaccuracies, assess their causes and determine how to correct them. After an initial effective, accurate battery volley, the instructor introduces leaders to four teaching missions of inaccurate fires--each one prompting the students to evaluate routine causes of inaccuracies at the gun or fire direction center (FDC). The STX uses a Gunnery Troubleshooting Job Aid, depicting the causes of lateral, range and combination errors in the target area, to review the types and sizes of errors resulting from failing to account for certain elements of data. See the job aid in Figure 2.

One Gun Range Error. One of the more common errors manifested in the target area is a simple range error for one gun due to an incorrect charge. In that case, Mission #1, a battery volley (four guns, in this case) looks like Figure 3.

Although some would contest that a charge error is not a very frequent occurrence in training, the frequency of missions during Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) in Afghanistan has forced units to deliver many rounds at significantly different ranges, employing multiple charges simultaneously, substantially increasing the likelihood of charge errors.

More importantly, the charge error is an excellent opportunity to use the tabular firing table (TFT) to examine the magnitude of an error and whether or not the range error exhibited is due to an incorrect charge. In the Figure 3 example, it appears that one gun (the firing unit directly below and behind the observation post) has fired significantly "long." The first two questions in Figure 1 isolate the error to one gun--the first requirement for the supervisor to begin troubleshooting the cause.

By employing a "right-by-piece" command, determining which gun fired the error is easy. The development of Mission #1 also presents an opportunity for the instructor to "coach" the students to the proper gunnery command.

Using the TFT and extracting the range associated with an elevation from the next higher charge enables the student to compare that range with the range to the target (announced by the fire direction officer, or FDO). If the difference between the two ranges is equivalent to the observed error in the target area, then the error is most likely an incorrect charge fired by one gun.

In this particular case, there are at least two other conditions that can cause range error on an individual piece, as noted on the Gunnery Troubleshooting Job Aid in Figure 2: quadrant elevation fired and propellant temperature. The job aid not only focuses the supervisor on the specific conditions to look at to isolate the cause, but also categorizes them by individual piece, battery or both. It is possible that the range error was produced by a large error in the quadrant elevation fired, so the supervisor must determine whether or not that was the cause.

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As before, this line of investigation presents an opportunity to coach students on how to ascertain this information without even stepping off the hill. The executive officer (XO) or chief of firing battery will ensure that the correct quadrant is reported-the answer obviously helping to determine if the error was due to an incorrect elevation set on the howitzer's elevating mechanism.

But, before a supervisor can move on, he must be absolutely sure this range error in one gun was not caused by an error in propellant temperature, another possibility listed on the job aid. Again, the learning point of Mission #1 allows the instructor to review basic principles of how propellant temperature affects the muzzle velocity of the round and, subsequently, the range of the projectile. Generally, warmer propellant causes a higher muzzle velocity if all other conditions remain the same.

Based on this principle and an evaluation of Tables E and F of the TFT, the student also can examine what muzzle velocity would be produced and if this would correspond to the magnitude of the error observed in the target area. Generally speaking, it requires a very large error in propellant temperature to produce small errors in range along the gun-target line.

One Gun Lateral Error. Mission #2 reinforces another element of the gunnery troubleshooting discipline--the lateral error. In the Figure 4 example, one round is errant and is a significant lateral error to the left. By reviewing the job aid, students isolate this error as a "deflection fired" problem.

Once again, the situation facilitates a discussion about errors on the gun that produce a lateral error as well as what rule guides evaluating deflection errors either right or left. Gunnery supervisors must have a solid understanding of the "LARS" rule (left add, right subtract). Consequently, the observed error well to the left of the target would have to have been caused by a much higher deflection (an "add" to the left) than should have been fired.

In the example, the deflection fired was reported as 3141. The deflection that should have been fired was 3114 (transposed digit in the last two digits). The error in meters on the ground can be further determined by multiplying that difference (27 mils) by the gun-to-target range in thousands (3.0), yielding a total error of 81 meters.

An experienced observer easily can assess whether or not 81 meters is equivalent to the observed error in the target area. If true, then the supervisor has accounted for all of the errors produced.

Battery Range and Lateral Errors. Using a similar approach, Missions #3 and #4 reinforce the range errors resulting from incorrectly applied muzzle velocity variations (MVVs) and a lateral error for the entire firing unit. These missions also allow the instructor to coach his students, prompting discussions about the proper questions to ask to isolate errors and to use the job aid to determine the cause of the errors.

This 90-minute live-fire STX has been executed four times this fiscal year with each hands-on iteration's receiving enthusiastic praise. It also has been varied slightly by bringing the Basic Officer Leader Course (BOLC) III and FACCC students in to produce an integrated and invigorating leader training period. It likewise invokes informal coaching at all levels of participation.

While more appropriately focused at FACCC students, this STX already has proven its merit as a part of the overall FA School Reset strategy. It is scheduled for incorporation into the revision of the FACCC by July.

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If units or leaders not attending courses where they can experience the Gunnery Troubleshooting STX have questions or would like more information on the training, they can contact the Officer Instruction Group of the 1st Battalion, 30th Field Artillery, Major Todd Perry at [e-mail] or call him at DSN 639-1565 or commercial 580-442-1565.

Resetting (or Re-Redding) Field Artillerymen, rightfully, is a priority to ensure Redlegs can execute FA fires for ground force commanders, when and where needed, during future full-spectrum military operations. Troubleshooting gunnery problems in live fire or simulations is a critical factor in FA Reset.

Colonel Kevin M. Batule commands the 428th Field Artillery Brigade, formerly known as the 30th Field Artillery Regiment, FA School, Fort Sill, Oklahoma. Previously he was a National Security Fellow at the John F. Kennedy School of Government at Harvard University. He commanded the 2nd Battalion, 320th Field Artillery (2-320 FA), 101st Airborne Division (Air Assault), deploying the battalion for Operation Iraqi Freedom (OIF) and participating in combat operations in Najaf, Karbala and Hillah, followed by stability operations in Mosul. He served as a Gunnery Instructor for two years in the FA School and, in the 101st Division, as the Assistant Fire Support Coordinator and Brigade Fire Support Officer (FSO) in the Division Artillery and S3 and Battalion Executive Officer (XO) in 2-320 FA. In 1-37 FA, 172nd Light Infantry Brigade at Fort Wainwright, Alaska, he served as the Assistant S3.

By Colonel Kevin M. Batule

Ask the Following Questions:
* Is it affecting my entire battery?
* Is it affecting just one gun?
* Is it a range error?
* Is it a lateral error?
* Is it a range and lateral error?
* Did the solution solve the entire problem?

Figure 1: Gunnery Troubleshooting Guide. Ask these questions to detect
and isolate the cause of the error while observing and inspecting all
elements of the gunnery team.

                                    Lateral Errors  Range and Lateral
            Range Errors Caused by  Caused by       Errors Caused by
Errors by:  Errors in--             Errors in--     Errors in--

Battery     * Site                  * Azimuth of    * Target Location
            * Square Weight           Lay (AOL)     * Observer Location/
            * Air Temperature                         Direction
            * Meteorological                        * Orienting Station
              (Met) Station Height                  * Met Data
                                                    * Wind Speed
                                                    * Wind Direction
Individual  * Charge                * Deflection    * Gun Location
  Pieces    * Quadrant Elevation      Fired
            * Propellant
              Temperature
Battery     * Muzzle Velocity
  and (or)    Variations (MVVs)
  Gun

Figure 2: Gunnery Troubleshooting Job Aid