US AAC/AAF Doctrine: FM 31-35, Aviation in Support of Ground Forces, 1942 - Chapter 2

CHAPTER 2: COMBAT AVIATION

SECTION I: ORGANIZATION

GENERAL

5. In addition to his duties as commander of support aviation, the air support commander acts as adviser to the ground commander. He normally functions under the army, theater, or task force commander.

6. Aviation units may be designated in support of a major ground force. The control is centralized in an air support commander who assigns the attack missions as the needs of the ground unit(s) develop. When the operation requires, aviation units may be specifically allocated to the support of subordinate ground units. When this is done the combat aviation unit receives its support missions from an air support control established at the command post of the supported unit. However, a combat aviation unit may also receive other support missions from the air support commander. Designation of an aviation unit for support of a subordinate ground unit does not imply subordination of that aviation unit to the supported ground unit, nor does it remove the combat aviation unit from the control of the air support commander. It does permit, however, direct cooperation and association between the supporting aviation unit and the supported ground unit and enables the combat aviation to act with greater promptness in meeting requirements of a rapidly changing situation. Aviation units may be attached to subordinate ground units. This is exceptional and should be resorted to only when circumstances are such that the air support commander cannot effectively control the combat aviation assigned to the air support command.

7. The agencies and channels of tactical control of combat aviation of a typical air support command are charted in figure 1. In this case an air support command is represented in support of a ground force consisting of an army. Agencies and channels of tactical control are shown in only one corps. An air support control is associated with the command post of each of the three corps and 3d Division of the III Corps. Air support parties are allocated to the III Corps as follows:

3d Division-Two with lower units.

2d Division-One with division headquarters.

Ist Division-One with division headquarters. For signal communication see chapter 5.

8. The command post of the air support Command is immediately adjacent to the command post of the supported unit-in this case an army. A representative of the ground commander of the supported units is always present at the air support command post. An air support liaison officer will always be at the command post of the supported unit.

9. Figure 1 also illustrates channels of air support control.

a. From the various air support parties and controls to the air support command post (broken lines). It should be noted that the attack order will go from the first control directly to airdrome.

b. From the air support command post to the various airdromes and to aircraft in flight either directly or through the airdromes (dotted lines).

c. From air support parties to air support control and then directly to, airdromes when in support of a specific ground unit, such as a division.

EMPLOYMENT

10. COOPERATION.-The basis of effective air support of ground forces is teamwork. The air and ground units in such operations in fact form a combat team. Each member of the team must have the technical skill and training to enable it to perform its part in the operation and a willingness to cooperate thoroughly.

11. FACTORS AFFECTING EMPLOYMENT.-The most effective employment of support aviation requires a consideration of many factors:

a. Local air superiority.-Local air superiority must be maintained to insure air support without excessive losses due to hostile aviation.

b. Economy of force.-This does not mean economy in numbers of airplanes applied to the objective, but economy of force by application to the right target at the right time. Aircraft are more vulnerable and less easily replaced than artillery. Only those targets which cannot be effectively and quickly reached by artillery should be assigned to supporting aviation.

c. Time and space-Consideration of time and space factors involve an appraisal of the mission, the distance from the airdrome to the point of action, the speed and reliability of signal communication, and the status of readiness of aircraft assigned to the effort.

d. Flexibility.-Flexibility is the ability to concentrate the air effort at short notice on a particular point or distribute it to many points within a relatively short time.

e. Limitation of aircraft.-Air support cannot be guaranteed. It may be limited by weather, enemy action, or mechanical failure.

f. Field of operation.-The area of operation of support aviation should not be restricted but should be sufficiently broad to permit timely attacks on enemy forces that jeopardize the success of operations of supported forces.

g. Weight of attack.-Weight of attack depends upon the number of aircraft employed and the rate at which operations can be Conducted. Security and avoidance of losses in the execution of attacks must be subordinated to the achievement of the maximum demoralization and destruction of the enemy.

h. Air cooperation.-Close cooperation and coordination with other air force elements in the same area are necessary. If operating outside the area of an effective interceptor command, the air support command should have made available to it sufficient pursuit aviation.

12. METHODS or EMPLOYMENT.-The ground force commander, in collaboration with the air support Commander, decides the air support required. The following are general methods for employment of combat aviation:

a. All combat aviation initially assigned to support of the major ground force with provisions for certain subordinate unit support assignment later.

b. A part assigned to support of the major ground force with the remainder assigned to support of subordinate elements.

c. Assignment of all combat aviation to support of the major ground force with provisions for a change to specific subordinate unit support while the aircraft are in flight.

d. All combat aviation assigned initially to support of subordinate units with provisions for control or target designation by certain units directly from an air support control or an air support officer to aircraft in flight.

SECTION II: INTELLIGENCE

GENERAL

13. The importance of military intelligence to the employment of support aviation is vital. Without factual knowledge of hostile activities and installations the effect of air support missions is minimized and in many cases nullified.

14. High standards of ability and training are required of intelligence personnel. Many are specialists in a particular branch of military intelligence. Of particular importance in this duty are the specialists in the interpretation of aerial photographs.

15. The intelligence section of the air support command post operates in conjunction with the operations section. Under such circumstances it is able to furnish the air support commander with timely and accurate information concerning the enemy capabilities, after considering the objective and the hostile activities, as influenced by weather and terrain.

16. Military intelligence procedures and objectives are described in FM 1-40 and 30-5.

SOURCES OF INFORMATION

17. All possible sources of information, ground and air, are utilized to obtain air support intelligence. Important sources, may be

a. Visual reconnaissance.

b. Photographic reconnaissance.

c. All air units in the locality.

d. Air warning and antiaircraft units.

e. Captured materiel, personnel, and documents.

f. Intelligence sections of ground units.

g. Air support parties and controls.

h. Intercepts.

18. Intelligence officers stationed at airdromes secure much important data by thoroughly questioning crews as they return from air missions. In addition these airdrome intelligence officers are charged with the mission of keeping the flying personnel abreast of the situation as fully as possible, utilizing the periods between missions to the fullest extent, and thus shortening the time of briefing combat crews immediately prior to departure on missions.

19. Ground troops should be thoroughly indoctrinated to report all bombardment or machine gun attacks by enemy aviation. The tendency of individuals and echelons undergoing air attack is to become engrossed in warding off the attack and forgetting to make a full report of the attack to intelligence agencies.

COLLECTION, EVALUATION, AND DISSEMINATION

20. Intelligence officers of all echelons must be trained to grasp the decisive elements of a situation, to evaluate the information obtained, and to prepare it for use.

21. Objective folders are prepared, in advance whenever possible, to apply to all possible objectives in the area of operations and in probable air theaters. In most cases the opportunity for air activity prior to actual combat will be limited, and the preparation of objective folders will have to be accomplished during the conduct of operations.

22. Close cooperation between all intelligence agencies, ground and air, must be achieved to provide timely knowledge of essential information by all concerned. Occasions arise where vital items of military intelligence to air units must be routed directly between air units without resort to normal channels. Such action must be taken when the situation justifies it.

23. All enemy information must be evaluated so that proper conclusions may be derived therefrom.

24. Dissemination of intelligence to individuals or units must be made according to the urgency of the subject matter. Immediate transmission of all intelligence data would congest the communication facilities. Therefore, it is of prime importance that matters which can be delayed be held for periodic reports.

SECTION III: COMBAT OPERATIONS

CONDUCT

25. Combined operations of air and ground forces must be closely coordinated by the commander of the supported ground force. All operations should therefore be conducted in accordance with well-defined and practical plans. (See FM 100-5 and 100-15.)

MISSIONS

26. Combat support aviation may be employed on the following types of missions:

a. Reconnaissance bombardment.-Bombardment aviation may conduct combined reconnaissance bombing missions by developing and attacking targets located by the mission.

b. Attack on defensive organizations.-Air attacks are executed against field fortifications and defensive organizations in the path of the supported ground forces, particularly mechanized and armored forces, when it is not practicable to employ other means of attack upon the desired objective in the time available, or when the added fire power and moral effect of air attacks are essential to insure the timely success of the ground force operation.

c. Attacks an enemy reserves and reinforcements.-Hostile ground forces moving toward the operation area of the supported force normally will be a remunerative target for bombardment aviation and should be subjected to air attack for the purpose of blocking or delaying their movement and for effecting their destruction or demoralization.

d. Attacks on hostile mechanized forces--supporting combat aviation attacks and destroys approaching mechanized forces and antitank units before they gain contact with the supported force. The supply and maintenance elements so essential to motorized and armored formations should be sought constantly.

e. Attacks an hostile aviation.-When other air forces are inadequate or not available, the destruction or neutralization of hostile aircraft or antiaircraft by support aviation may be necessary.

f. Support of parachute and other air-borne troops.-In the support of this type of operations, friendly pursuit operates to gain and maintain effective air control over the objective for the period of the operation and provides security, to air-borne troops while in air transit and during landings. Supporting bombardment aviation conducts initial attacks when necessary to neutralize the enemy ground defenses at or near the objective and maintains sustained support until the objective of the supported unit has been gained. Air attacks are directed against ground targets at or near the objective that oppose the operations of the supported air infantry on the ground and against enemy reserves or reinforcements that threaten the supported force.

TARGETS

27. Unless the situation is critical, targets usually will not be selected within the effective range of the weapons of ground forces. (See par. 26b.) Small targets due to dispersion, camouflage, or concealment are not suitable targets for support aviation. Commanders must consider the employment of combat aviation in the light of the hostile air and ground situation and not as a weapon which can be applied with equal value in all circumstances.

28. Air support targets on the immediate front or flanks of supported units are generally transitory targets of opportunity. These targets may include troop concentrations or movements, artillery in position or in motion, minor field fortifications such as pill boxes, armored forces and tanks in assembly or in motion, motor columns, bridges of military value, and various field installations. The employment of dive bombers is indicated against these targets.

29. Air support targets not on the immediate front or flanks may include command posts, lines of communication, ammunition and bomb dumps, troop concentrations in bivouac or on the march, airdromes and aircraft thereon, tank concentrations, etc.

30. Rules cannot be laid down for the selection of the type of aviation to be employed against certain types of targets. The method of attack and equipment to be used must be determined by the air support commander or air support control after a consideration of all the factors affecting the employment of available aviation in the particular operation.

31. The most important target at a particular time will usually be that target which constitutes the most serious threat to the operations of the supported ground force. The final decision as to priority of targets rests with the commander of the supported unit.

32. Secondary targets should be assigned in each attack mission in case the primary target cannot be attacked.

33. Targets may be developed by ground reconnaissance or air reconnaissance and aerial photography.

34. Targets must be accurately indicated to the attacking aircraft.. Targets may be designated by

a. Use of maps and map substitutes with well-understood grid systems or with a coded template,

b. Marked aerial photographs, either vertical or oblique.

c. Polar coordinates with reference to a terrain feature which can be identified from the air.

d. "Leading in" of combat aviation by observation aircraft.

e. Visual ground signals such as

(1) Arrow or "V'' on ground pointing to target with range indicated by proper number of crossbars or disks, each representing a definite distance.

(2) Vehicles in prearranged formations.

(3) Firing tracer ammunition or artillery or mortar smoke to mark a reference point.

(4) Signal lamps and lights.

(5) Pyrotechnics.

f. All ground units must be trained so as to assist air units in every way possible in reaching their target.

PLANS AND ORDERS OF GROUND AND AIR COMMANDERS

35. GROUND COMMANDERS-In addition to normal data concerning reconnaissance and intelligence missions, the field orders of the supported commander should contain at least the following instructions to air support aviation:

a. Mission of support aviation.

b. Method of air support.

c. Designation of units to receive direct support.

a. Area In which support aviation is to operate or be prepared to operate.

36. AIR COMMANDERS.-a. The air commander must be so trained in the tactical employment of elements of his command that, given a specific objective, he can evolve a plan of action to fit the situation at hand. However, the situation may change prior to arrival at the objective, in which case the secondary plan of action will be put into effect.

b. The air support commander will issue complete orders when time permits, but normally the instructions will be in fragmentary form or according to a prearranged form. The following items are necessary for lower air units to enable them to prepare for operations:

(1) Assignment of units to support the ground force, including priority, limiting times of attack, bomb loading, routes, and aviation assistance.

(2) Instructions to units detailed for support of particular subordinate units.

(3) Necessary instructions as to bomb loadings.

(4) Instructions concerning bomb safety lines with effective time limits.

(5) Assignment of missions to observation units.

(6) Allocation of air support control and air support parties.

(7) Special signal communication instructions.

c. Air support to carry out both ground and air commanders' orders in the case where a unit is specifically assigned to the support of a particular ground unit, such as a division, will be carried out in accordance with the procedure and control as outlined in paragraph 37.

AIR SUPPORT MISSION PROCEDURE

37. INITIATION OF REQUESTS.-a. General.-Requests for air support originate with any unit commander and follow normal command channels until they reach a command post where there is an air support party. The commander initiating the request will include the following information:

(1) Type or designation of target.

(2) Exact location of target by best means available. (See par. 34.)

(3) Direction of movement of target.

(4) All particularly distinguishing characteristics of target.

(5) Location of friendly troops with respect to target.

(6) Time limits of requested support if necessary.

b. Transmission of request.-At the air support party the air support officer will advise the commander of the ground unit with which he is operating as to the practicability of execution of a mission and as to the advisability of requesting it. If the ground commander approves the request it will be forwarded without delay to the air support control.

c. Evaluation of request.-At air support control the air support officer in collaboration with the commander of the supported unit evaluates the request considering the following factors:

(1) Identification of target and location.

(2) Time limits of attack.

(3) Importance of target in furtherance of ground plan

(4) Number of airplanes required to destroy or neutralize the target.

(5) Number of airplanes available at airdrome and their status of readiness.

(6) Weather conditions along route and at target.

(7) Type of bombs and ammunition required.

d. Decision on request.-The decision as to whether or not an air support mission will be ordered rests with the commander of the supported unit. Such decision must comprehend full consideration of the air support commander's advisement as to air means available and the ability of aviation to perform successfully the mission ordered. (See par. 109.)

e. Notification of decision to source.-When the decision has been reached as to whether or not the mission will be ordered, the air support control will in all cases advise the requesting unit through the air support party as to the action taken, stating reasons if mission is not ordered.

f. Transmission of orders.-If the request is approved it will be forwarded in attack order form directly to airdrome of supporting unit for compliance.

g. Air action on orders.- Upon receipt of an attack order, the unit at the airdrome will take the necessary action in conformance with its state of readiness to insure success of the attack.

h. Air report on execution of support mission.-Immediately upon return of the airplanes to the airdrome, the air unit commander will report directly to the air support control where the order originated, -giving results of mission and all pertinent intelligence data.

i. Ground report on result of attack mission.-After the attack by support aviation, the commander who requested the support will report results of attack to air support control through the same channels that wehre used for the original request.

j. Priority status of requests.-Requests for air support should have priority over all other matters on the air support control net. See paragraph 114 for suggested forms for messages and attack orders.

ATTACKS

38. The approach, formation, altitude and delivery of attack are matters of technique for the supporting air units concerned and are beyond the scope of this manual.

39. TIMING.-a. The timing of the air attack is of primary importance in securing the maximum effect.

b. When friendly troops might be endangered, definite time limits for the commencement and termination of the attack should be prescribed. time allowances for action upon air requests, the transmission of the attack order through channels, the aircraft to leave the ground, and for the flight to the objective must be carefully computed in determining the time of attack.

c. When the nature of the attack permits, the firing of prearranged flares by the last element of the combat aviation may serve to signal the end of the air attack as well as a signal to launch the ground attack. The ground attack may be launched on the signal from the combat aviation or at the end of the time bracket, whichever comes first.

d. In some cases the exact time a target may be most exposed or attacked to greatest advantage cannot be fixed when the attack order is given. In such cases an attack may be ordered when a particular condition occurs (crossing bridges or exposed area, debouching from cover, within a defile etc.), rather than at a precise time.

40. TYPES OF BOMBS.--a. Bombs that are most generally used by support aviation are

(1) Fragmentation.

(2) Demolition from 50 pounds to 250 pounds.

(3) Chemical.

(4) Incendiary.

b. The most effective bomb in any instance depends on the target against which it is used.

STATUS OF AIR UNITS

41. In support operations when targets cannot be foreseen and developed sufficiently in advance for normal air operating procedure, special provision must be made to minimize the time lag between requests for missions and their execution. Frequently such targets will be encountered in a fast moving ground situation wherein time will be the vital factor in any air operations conducted.

a. Alert status.-To meet this time requirement, a suitable portion of supporting combat aviation should be maintained on "alert" status, either ground or air, prepared to proceed to and attack, with the least practicable delay, any assigned target. This will necessitate that the aircraft previously be armed and serviced. In this connection, it is highly desirable in support operations that the number of types of loading be restricted to one or two except for a special operation.

(1) When aircraft are ground-alerted, the pilots station themselves in the immediate vicinity of the unit operations office or their aircraft, ready to receive final instructions. Procedure should be developed to minimize the time required to clear the airdrome after instructions and orders are issued.

(2) In fast moving situations when "ground alert" does not permit timely attacks, it may sometimes be necessary to "air alert" a portion of the supporting force for the attack of targets of opportunity that constitute an immediate threat to the operations of the supported ground force. Air alert is highly uneconomical and can be maintained only for short periods of time. When airplanes are on air alert, direct airground communication with supported unit will be normal.

b. Period of operations.-The commander of the supported unit and his air support control must be thoroughly familiar with the importance of conserving the supporting air units by careful control of combat crew state of readiness. From experience gained abroad and in this country it has been established that, for continuous or sustained operations, an air support unit can operate for protracted periods, if not to exceed a ratio of about 25 percent of the combat crews are on alert status, 25 percent readiness status, and 50 percent released. It must also be borne in mind that as part of the unit is ordered out on missions other crews must replace those ordered out, and so advance their state of readiness. Combat crews on "alert" are seriously affected by fatigue due to the tension and discomfort of being in full flying gear and in immediate expectation of taking off. When an attack order comes in, personnel must be ready instantly to plan their attack, be briefed by intelligence, go to their airplanes, which are usually dispersed, check their equipment and take off. It should therefore be exceptional  for combat crews to be held on alert status when there is no immediate prospect of missions being ordered. In all cases due consideration should be given to the conservation of combat crews as related to the immediate ground situation. For a decisive operation limited in time, the maximum number of aircraft should be placed in highest readiness status that contemplated employment will permit.

c. Limitations-In this connection, it is important to consider the uncertainty of sustained strength in participating aircraft. Only the number available for initial operations can be definitely determined. Neither the numbers which will return, nor the time at which those that return will be available for future action, can be predetermined with any reliability. In these circumstances, the number of aircraft immediately available will, after the opening phase, fluctuate throughout the operation. This fluctuation is an important limiting quality of air support.

NIGHT OPERATIONS

42. High altitude bombing can be conducted at night whenever the conditions are such that the target can be seen and the necessary sighting operations performed. Artificial illumination of the target is frequently necessary. For such attacks using the flight, squadron, and glide methods see FM 1-10.

43. Minimum altitude bombing, usually by airplanes operating singly, can be effected against very profitable targets, such as motor and troop columns, which habitually operate under the protection of darkness. For night bombing operations see FM 1-10.

SAFETY MEASURES AND GROUND IDENTIFICATIONS

44. Up to the present no satisfactory method has yet been developed that will insure immunity to troops from attacks by its own bombardment. However, the chances of bombing friendly troops can be held to a minimum and the chances of error reduced by careful attention to the following:

a. Briefing of combat crews.--Thorough and complete briefing of combat crews by unit intelligence officers prior to a mission, giving as accurate and up-to-the-minute picture of friendly ground activity and location as is possible before take-off.

b. Target designation.-Complete and detailed location and description of target with respect to prominent landmarks. Also direction and rate of movement of target or its probable movement. Pictures, drawings, and other helpful data should, if possible, be furnished to flight leaders.

c. Timely notification of situation changes.-Immediate priority advisement by ground commander to associated air support agency of any affecting changes in friendly troop dispositions occurring subsequent to a specific request for support mission.

d. Identification of enemy.-Thorough training and indoctrination of air and ground personnel in visual identification of enemy and friendly uniforms, materiel, formations markings, and signals. Provisions must be made by responsible commanders for combined training of air and ground troops, leading toward the development of satisfactory mutual identification methods in order to increase the effectiveness of their combined operations.

45. IDENTIFICATION, FRIENDLY Troops.-Among the methods of identifying friendly troops and reducing chances of being bombed by friendly aircraft tried with limited success both in this country and abroad are

a. Establishment of bomb safety lines readily identified from the air.

b. Visual signals prescribed to identify ground elements to friendly aviation. Examples of visual signals are panels, flags, pyrotechnics, lights, smoke, marking of vehicles, and arrangement of vehicles in certain formations.

c. Radio communication with aircraft in flight.

 46. Methods to identify friendly troops to friendly air units must constantly be sought and tested. These methods may be of a secret nature and should be incorporated in signal operation instructions.