US AAC/AAF Doctrine: FM 31-35, Aviation in Support of Ground Forces, 1942 - Chapter 4
CHAPTER 4: AIR TRANSPORT
SECTION I: GENERAL
77. LIMITATIONS.-The movement of troops and their equipment and the movement of emergency supplies by air transportation are entirely practicable within the limitations of aircraft in general and the available types of airplanes and gliders in particular. The principal factors limiting the use of aircraft in air transport operations are
a. Availability of suitable and sufficient aircraft and crews within the time limit allowed by the situation.
b. Performance characteristics, that is, speed, range, carrying capacity.
c. Ground facilities at points of departure, intermediate landing points, and points of destination.
d. Weather.
e. Enemy activities.
78. PRACTICABILITY.---a, In the consideration of the use of air transportation, the importance and urgency of the operation must be weighed against the fact that this is the most expensive form of transportation available. It is expensive not only in money, but also in terms of fuel consumed, wear and tear on and possible destruction of the aircraft involved, and in the interruption in the performance of the normal missions of these aircraft for the time required. It is also expensive in terms of equipment and supplies for the transported troops. The amounts of these items accompanying the troops have to be held to a minimum and the troops are deprived of the use of the remainder until it can be brought to them at later times.
b. Air transportation is usually thought of in terms of its rapidity. However, it is faster than other methods only after the airplanes are under way. The coordinating and planning, movements to points of departure, and loading require fully as long as the older methods. The difficulty of reaching an objective due to its geographical location and/or enemy activity, rather than the time element, will be the chief factor calling for the transportation of large detachments by air.
c. Various factors at present render it inexpedient to hold large concentrations of airplanes together for such movements. Thus any troop movement will have to be foreseen or delayed a sufficient time to permit the required aircraft to be assembled. At present, large troop movements by air, except to relatively inaccessible destinations, require an overall time interval comparable to or even longer than that for other means more immediately available.
79. PLANNING.-The necessity for planning for air transportation operations in greatest detail and with thoroughness must be recognized if confusion, delay, and even disorganization are to be avoided. Such operations are more delicate than are similar ones by more conventional means. Efficient liaison between transporting and transported units is a prerequisite, and opportunities for rehearsal and practice should not be neglected.
a. Protection for the troop movements is a primary consideration for all concerned. Two major factors which contribute to such protection are secrecy of projected operations and friendly aviation.
b. Steps to maintain secrecy regarding large troop movements must begin with the inception of the plan so that reports of unusual concentration or activities involving transport airplanes, even those occurring in interior zones, will not reach the enemy. Actual flights should avoid thickly populated areas and preferably should be made at a very low altitude or at night.
c. Adequate pursuit protection must be arranged for. It is axiomatic that air superiority is a prerequisite to successful aerial troop movements.
SECTION II: TROOPS INVOLVED
80. PARACHUTE Troops.--a. Parachute troops are specially organized for and trained in moving by air. Their equipment is such that no difficulty is experienced in carrying it by airplane except that a certain number of the airplanes must have large "cargo" doors through which equipment bundles may be dropped in tactical operations. All airplanes carrying parachute troops must be equipped with a suitable longitudinal steel cable for the attaching of parachute "static" lines. Parachute troops provide their own parachutes. Strategical movements of parachute troops may or may not be made by air; tactical missions always involve air transportation.
b. Air transport operations involving parachute troops consist in carrying them to a jumping point over or near their objective, protecting them en route, and supplying their essential needs by air thereafter for as long as the situation demands or permits. Not infrequently bombardment support at the objective will be indicated.
81. AIR-BORNE TROOPS.-a. Air-borne troops, other than parachute troops, will consist of the combat elements of ground units plus a minimum of essential service troops. In small scale operations, these troops will generally be from infantry units. Large scale operations will usually include combat elements of other arms and services. Parachutes for these troops will be supplied by transporting units.
b. Air operations involving air-borne troops other than parachute troops may be undertaken independently but usually will be made in conjunction with the parachute troops. Such operations will consist of transporting these troops to and landing them at their destination, protecting them en route, and providing a supply and evacuation service for as long as the situation demands or permits. Because of the necessity for landing the troops at their points of destination. both gliders and airplanes may be used.
SECTION III: TRANSPORTATION EQUIPMENT
82. GENERAL.-Transportation equipment primarily consists of transport airplanes and gliders. Other types of airplanes such as medium and heavy bombardment may be used, but transport airplanes will usually be made available.
a. Present transport airplanes have seats for from 12 to 28 passengers, depending upon design. However, the number of passengers who may be carried depends upon the weight of engine fuel, baggage, equipment, and supplies which have to be carried in each airplane. Thus particularly in aircraft with large seating capacity, the number of soldiers carried may not equal the number of seats because of the essential accompanying items. The determination of the carrying capacity of the airplanes and consequently the number of airplanes for each particular operation is a technical task for the air staffs concerned. Aircraft are not standardized to the extent of other forms of transportation, and small variations in weight and size are important.
b. Present transport airplanes have medium cruising speeds ranging from 140 to 175 miles per hour depending upon design, can carry up to about 6,000 pounds, and can land in about 1,800 feet over a 50-foot obstacle. Capabilities of the aircraft will be reduced when gliders are being towed. Present transport airplanes carry no armament.
83. GLIDERS.-Troop-carrying gliders have been constructed in the 8, 15, and 25 place sizes. Several of the smaller sizes may be pulled by one towing airplane. They are intended to be towed to and cast loose in the vicinity of their destination, and to glide to a landing. They carry no armament. Among the advantages possessed by gliders are their cheapness, rapidity of construction from materials readily obtainable, ease of maintenance and repair, silent approach, and slow landing speeds which enable them to land in small fields. Most of the problems involved in air transportation are common to the use of both airplanes and gliders.
84. MAINTENANCE.-The air transport units must be accompanied by adequate maintenance, communication, and administrative personnel, and facilities. Aircraft for tactical troop movements must be in flying condition at the designated time and place, and in the designated number. Failure to achieve this will place the success of the maneuver in jeopardy from its beginning.
SECTION IV: OPERATIONS
85. GENERAL.-Air transportation may be either of a strategical or tactical nature. In either case the basic problems of securing the airplanes and coordinating, organizing, planning, protecting, and conducting the movement are largely the same.
86. COMMAND.-In most strategical and tactical movements, command of transporting units will usually be vested in the air support commander of the supported force with direct communication authorized between transporting and transported units. For operations of an independent and continuous nature, ground troops to be transported and the air transport units may be organized into an air-borne task force with the operational control of all components vested in the task force commander.
87. FEASIBILITY.-When the necessity or desirability for air transportation arises, preliminary steps must be taken to determine if the operation is within the capabilities of aircraft and if aircraft of the desired types and in the desired number can be made available for the operation. In small operations where the use of airplanes of supporting aviation units is contemplated, these facts are readily ascertainable. However, large air transport operations will necessitate securing numerous airplanes from several sources.
88. TRANSPORT ASSEMBLY.-Whenever practicable, airplanes for large troop movements should be concentrated far enough ahead of time to allow for preparatory organization and training for the movement. While permanently organized and well-trained air transport units should be provided insofar as is possible, some provisional organizations may have to be constituted. Transport airplanes on their normal cargo runs fly singly whereas troop movements require precision in take-offs, formation flying, and landings for efficiency and protection. In addition, parachute troop operations require that airplanes fly in special formations which may vary with each operation. Time spent in pre-operation training will do much toward insuring the success of the operation itself.
89. COORDINATION. As soon as possible after an air transport movement has been decided upon, qualified liaison officers should be exchanged between the transported and transporting units for the duration of the operation, and a conference between the commanders should be held. At this time a clear delineation of the activities and responsibilities of each should be understood.
b. The delineation of activities and responsibilities between transported and transporting units will include these points: The transporting unit will be responsible for the preparation of all plans pertaining to the use and allocation of the air force equipment and personnel in a manner as favorable to the desires of the transported units as technical and tactical conditions permit; the transported unit will be responsible for proper loading and unloading of personnel and supplies in accordance with plans provided by the transporting unit. The movement will be under the command of the transport unit commander during time of actual flight except that, when parachute troops are being carried, direction of individual airplanes may be temporarily relinquished to the jumpmasters on the final approach to the objective.
c. The commander of the troops to be transported should furnish the following information for each of his units to the air transport commander at their conference:
(1) Point or points of departure.
(2) Time of departure or arrival.
(3) Intermediate stops.
(4) Destinations.
(5) Method of movement, such as by one flight or by shuttling.
(6) Number of men to be carried and average weight of each including personal equipment. In movements likely to culminate in combat this information may be given in terms of numbers of combatant units, each composed of personnel, combat equipment, and supplies. These combat units should be standardized into a minimum of types. For example, a rifle battalion can be organized for the movement into two types of small units, one being similar to a rifle squad and, the other being similar to an antitank squad. The composition of such units will be furnished. Each airplane will then carry whole multiples of these small units with remaining capacity, devoted to other items.
(7) Weight of equipment and supplies to be carried.
(8) Information relative to equipment and supplies of unusual weight or bulk such as antitank weapons, reconnaissance, or other vehicles. Any object too large to be carried through an airplane passenger-size door is in this category.
(9) Information relative to type of formation to be flown.
(10) Information relative to the transportation of subsequent supplies to the troops during the course of operation, if such is contemplated.
(11) Information relative to practices or rehearsals desired.
90. PLANNING, GENERAL.-After, or concurrently with, the foregoing conference, the air transport commander and his staff should proceed to plan the operation in great detail. This planning will include among other things the following:
a. The assembling of equipment, supplies, and ground personnel, and the assembly points therefor.
b. Signal communication.
c. Pre-operation training for the movement.
d. Movements of transport units to advanced bases.
e. Each troop-carrying phase of the operation as discussed in paragraph 91.
f. The movement of supplies as discussed in paragraph 94.
91. PLANNING, DETAILED.-Troop movements must be planned in great detail and the information disseminated to those concerned early enough to be of use. The points covered should include the following:
a. A parking and loading plan at the point of departure. This plan should show the parking location of each airplane, its designated number for the particular operation, the- pilot's name, and load to be carried, imposed upon a sketch or photograph of the field. Distribution of this plan should be made to air personnel and to the troops to be transported so that the latter will be able to locate and load the airplanes without confusion, or will be able to spot their personnel and equipment for loading prior to the arrival of the airplanes.
b. Plan of take-off and assembly into formations, distribution to include each pilot.
c. Flight formation plan showing the location of each plane by number and pilot's name in each formation. Distribution of this should include the transported troops.
d. Flight plan giving routes, times, altitudes, speeds, and check-points for the flight, distribution to include each pilot.
e. Landing and unloading plan at destination. This should show the location of each airplane when stopped and ready for unloading at the destination, imposed upon a sketch or photograph of the landing area. Distribution should include the transported troops.
f. Signal communication instructions Including visual airground signals at destination, distribution to include each -pilot.
g. Enemy activities and installations.
h. Coordination of the air movement with friendly forces. Pursuit protection must be secured in sufficient strength to insure air superiority en route to and from the destination. The movement must also be coordinated with other friendly aviation assisting the operation and with antiaircraft units in the flight path.
i. Means for regulating the movement. Positive means must be provided for insuring adherence to the flight plan and for maintaining flight discipline during the air movement.
j. Special instructions applicable to the situation such as action to be taken in case of enemy attack, unexpected enemy resistance at the objective, alternate friendly airdromes, and instruction in regard to alternate objectives or crash landings at destinations.
92. In view of the hazardous nature of even the initial phase of an operation of this kind, every effort should be made by all concerned to avoid last minute changes in plans. Such changes usually result in much additional work for the air units involved and may easily lead to delay and confusion, if not jeopardy. Some last minute changes- are probably inevitable in field operations, but they should not be due to lack of study or foresight.
SECTION V: EMERGENCY SUPPLIES BY AIR
93. In general, the same limitations and fundamentals of procedure and planning that govern the movement of personnel also govern the emergency movement of supplies by air, except where obviously inapplicable. (See pars. 89-92.)
94. METHODS AND PRACTICE-Emergency supplies may be delivered at their destinations by dropping, in gliders, or by airplanes landing.
a. The delivery of supplies by dropping may be the most practicable means in the situation to be met but is in every way a laborious procedure. Supplies to be dropped have to be strongly and carefully packed in bundles of limited size, dropping equipment is required for most articles, a portion of the supplies dropped will probably be damaged or irrecoverable by the recipients, and facilities available will usually limit the quantities which can be delivered in this manner.
b. Certain items may be dropped free without damage. Other supplies may be dropped free with the expectation of and allowance for some loss and damage. Such supplies should be packed in several layers of canvas, in several sacks, or in strong crates so that the contents will not be scattered when the bundles land.
c. Supplies to be dropped by parachute should be packed in bundles weighing approximately 200 pounds. Special equipment parachutes and containers have been developed but if these are unavailable, personnel parachutes with an arrangement for pulling the rip cords can be used.
d. When possible, prearranged visual signals should be used to identify the ground troops, to indicate the dropping field, to signify an intention to drop supplies, an affirmative, and a negative signal. When such communication has been arranged, supplies will not be dropped until an affirmative signal has been received from the ground.
e. The dropping field preferably should be flat with minimum dimensions of 30 by 100 yards and free of obstructions. To insure greater accuracy, bundles will be dropped at the minimum altitude from which the parachute will operate and with the airplane at slow speed.
f. Recipients must take precautions to avoid injury to personnel and equipment by falling bundles. Parachutes, containers, and other dropping equipment shall be taken care of properly and returned to the transporting unit.
95 - BY GLIDER.-Gliders may be used for delivering emergency supplies with all the advantages peculiar to that type aircraft. Particularly are they valuable because of their comparatively large carrying capacity and their ability to land in comparatively small areas. Signal arrangements similar to that described in paragraph 94d are desireable.
96. By AIRPLANE.-Where landing areas are available and enemy activity permits, airplanes may deliver emergency supplies in normal manner and the problem is correspondingly simplified.
SECTION VI: AIR AMBULANCES
97. Evacuation of sick and wounded personnel by air will often be necessary. If specially designed air ambulances are not available, ordinary transport airplanes with necessary improvisations may be used. In the latter case the number of litter, in contrast to the number of ambulant patients, must be included in the information furnished the transport commander.
98. In movements of this kind, close coordination and cooperation should be effected with the medical units involved.
99. Airplanes used exclusively for carrying sick and wounded personnel will be marked in accordance with international law.
SECTION VII: TARGET AND TRACKING
100. Tow target detachments may be assigned to air support commands. The mission of these detachments is to provide aerial targets for the antiaircraft training of ground troops. They accomplish this by providing airplanes for antiaircraft artillery tracking missions, by towing targets for antiaircraft firing practice, and by the use of radio controlled targets.
