Field artillery was not the only source of indirect firepower available to British troops and their allies.  Other branches of the Royal Artillery provided some, as did infantry mortars and the allied naval and air forces, although technically the latter delivered direct fire.

ARTILLERY

In addition to field artillery three other branches of the Royal Artillery provided general firepower from time to time as part of the all-arms battle in World War 2 (WW2) in addition to their specialist tasks:   Anti-aircraft (AA), Anti-tank (ATk) and Coast.

Anti-Aircraft Artillery

As the war progressed the air threat decreased and both heavy and light AA units were used in the field role.  HAA batteries equipped with the 3.7-inch HAA gun had in theory long range (18,600 yards at full charge), unrestricted top traverse and were typically handled as medium artillery, and often used for CB tasks.  Their high rate of fire and time fuzes were an added bonus, the latter were particularly useful but  their maximum settings limited their range.  The powder burning Fuze No 199 was limited to 9,200 yards and the mechanical No 208 to 16,200 yards.  However, it was important to have the correct angle of sight, muzzle velocity and meteorological data for effective predicted fire.  It's not clear if direct action fuzes (Nos 117 or 119) were used instead of time fuzes, but a reduced charge was introduced for ground fire in order to reduce barrel wear.  

In Italy statistics reveal that many HAA regiments fired only a few thousand rounds at air targets but perhaps 50 times as many at ground targets!  Most of this fire was indirect although HAA units were not officially issued with the necessary fire control equipment until late 1944.  OPs from field and medium regiments usually provided observation and tactical fire control, unless the guns were being used for CB fire.  

40-mm LAA was usually used for direct fire, although there is at least one recorded incident of LAA being used for indirect fire controlled by an air observation post (AOP).  There were occasions, particularly in Italy, when LAA batteries temporarily operated mortars.  More frequently LAA fire was used to mark the edges of a barrage, their tracer provided a line, to help keep the infantry on the right course particularly at night.  This 'directional aid' was first used at El Alamein.  LAA fire was also a feature of the 'pepperpot' element that characterised large fireplans from late 1944.  As a directional aid range was limited by tracer 'burn-out', 7 second tracer to 3,200 yards and 12 second to 5,300 yards.  However, 40 mm shells had limited effect individually but the high rate of fire concentrated on a target was effective, although the guns were vulnerable.

One problem was that AA guns were designed to fire short bursts at infrequent targets.  However, in the field role, particularly 3.7-inch when firing as part of a fireplan, they were required to fire for periods of a few hours. This caused equipment failure and the guns got so hot that paint on the barrels blistered and on one occasion at least the barrels were visibly drooping.  A second possible issue was that 3.7-inch HAA shells had been designed to produce quite large fragments to maximise damage to aircraft.  This meant that a burst produced fewer and bigger fragments that needed to create battlefield casualties.  Of course this didn't matter too much when neutralisation was required.

In the final months of the war in NW Europe HAA brigades were used as AGRAs in major fire plans.

Anti-Tank Artillery

Anti-tank guns were operated by artillery, infantry battalions and divisional reconnaissance regiments.  Those provided by artillery were in divisional anti-tank regiments with additional regiments commanded by higher formations and allocated as required.  The other arms had one or more platoons per battalion.  Initially anti-tank guns were limited to armour piercing ammunition.   However, in early 1944 HE ammunition was authorised for direct fire tasks.  The concern had been that too much HE would mean too much wear to the anti-tank guns and consequently lose accuracy for their anti-tank role.   The HE ammunition scale was:

This led to anti-tank guns increasingly used in their secondary role for direct fire against hard targets such as bunkers, 'pill-boxes', MG posts, snipers in houses, OPs, etc.  In effect a similar role to assault or infantry guns in other armies. This first happened in N Africa at the beginning of 1941 using 37-mm Bofors.  However, 'concrete busting' with 17-pdr became fairly usual in Italy and 3-inch M10s were also found to be very useful for dealing with strongpoints such as houses or bunkers.  Other uses included troops behind light cover, soft skinned vehicles, nuisance harassing fire and cutting wire obstacles.  These targets would normally be engaged with direct fire, at least until they became obscured by smoke and dust when there was the option of changing to indirect fire.  In general indirect fire was only used if the target could not be engaged by field artillery and there was no problem of crest clearance, at least until reduced charges were introduced early in 1945.  The absence of full range tables was also a consideration.

From time to time RA anti-tank troop commanders and battery officers inevitably acted as forward observation officers (FOO) for field artillery units, although their limited communications inhibited this.  Finally, 17-pdrs were given an indirect fire capability to enable them to continue attacking structures that became obscured but dust and smoke during the direct fire engagement, they may have been occasionally used for more conventional indirect fire.  This involved fitting a dial sight and plane for a field clinometer.  M10 were also used for indirect fire on some occasions.

In late 1944 anti-tank regiments in Burma became dual equipped, every anti-tank detachment had a 3-inch mortar. Australian tank attack regiments received both 4.2-inch mortars and 75-mm howitzers. Given the Japanese lack of tanks all this was a sensible use of resources.  However, the same thing was sometimes done in Italy from early 1944 using 4.2-inch mortars, most notably by the Polish Corps at Monte Cassino and in some anti-tank regiments one or more anti-tank batteries were converted to 4.2-inch mortar batteries.  In the Italian theatre divisional commanders had 4.2-inch mortars available for issue as required and it is these that were used.  

Coast Artillery

Apart from the Royals Marines' Mobile Naval Base Defence Organisation, most coast guns were in fixed mountings to provide layered defence against attack from the sea.  The opportunities for them to support the field army were very rare.  The main coast armament were the 9.2-inch guns of the counter-bombardment batteries, these guns being designed to engage ships up to 8-inch gun cruisers.  They were backed up by 6-inch and smaller guns  However, most coast mountings could engage targets throughout a fairly wide traverse although their maximum range depended on how much elevation their mounting allowed.   Coast guns were used quite extensively against targets on land during the battles for Hong Kong and Singapore.

Singapore was unique in having 15-inch coast guns but their traverse was not as wide as the smaller calibres although they did engage some land targets, but only with armour piercing shot because there was no HE for them in Singapore.  However, the batteries were incomplete when Singapore was captured and the remaining two 15-inch guns were then installed at Dover.  In 1944 these, under control of an AOP, were used in support of the 3 Cdn Division in its operations in the Pas des Calais area, by which time they were on their third set of barrels!  They were probably the most used coast guns in any western country.

In 1940 a new type of 'coast defence' unit was formed.  These were the 'beach defence regiments' usually equipped with assorted guns of WW1 vintage, including those provided by the US under 'lend-lease', and officially designated 'Defence Regiments'.   Most were in UK  but overseas units included a regiment in Singapore and a battery in Hong Kong.

In the SW Pacific both Australia and New Zealand formed mobile coast defence units.  A few of the Australian batteries, equipped with 155-mm Gun M1918 (US built version of the French 155-mm GPF) were used to support operations on land.  Of the 'coast' units these were probably the only ones, apart from the 15-inch at Dover, that were in any way integrated into the field artillery system.

FIREPOWER FROM OTHER ARMS

Mortars

Only in Burma did RA operate mortars as main equipment, some African artillery regiments there had 3-inch mortars as did a battery in jungle field regiments (usually with 16 'tubes').  This is in addition to the previously mentioned 'dual equipped' anti-tank regiments or those in Italy with batteries locally converted to heavy mortars, either temporarily or permanently.  In Burma in early 1945 a new longer range version of the 3-inch mortar and its ammunition started to be issued to artillery.

In North Africa. the Chemical Warfare Companies of the Royal Engineers (RE) operated 4.2-inch mortars from El Alamein onwards using conventional ammunition.  However, from about mid-1943 the divisional machine gun battalions (one per infantry division) converted one MG company to 4.2-inch mortars (16 mortars in 4 platoons) and RE stopped using them.  4.2-inch mortars reached Burma somewhat later in the war, although the Australians in the SW Pacific had them earlier.  

At the beginning of the war each infantry battalion had, in addition to a 2-inch mortar in every rifle platoon, a mortar section (2 × 3-inch).  This was increased to 3 sections in most battalions from late 1940.  Divisional reconnaissance regiments in infantry divisions also had a 3-inch mortar platoon but the motorised battalions in armoured brigades did not.  

The degree of co-ordination between non-RA mortars and artillery varied, although infantry divisions had a 'support group commander' responsible for coordinating infantry 'heavy' weapons, a role viewed somewhat sceptically by RA officers.  Mortars were used in the 'pepperpot' element of major fireplans towards the end of the war in Europe.  However, 4.2-inch mortars were often used for counter-mortar tasks under the control of the counter-mortar staff, not least because the could reach enemy mortar positions on reverse slopes.  In Burma it became normal practice for all medium and heavy mortars, both artillery and infantry, being coordinated as part of the artillery plan.  This included the infantry mortars being surveyed and adopting artillery fire control methods.  In the final months of the war infantry mortar platoons in Burma started re-equipping with 4.2-inch mortars.

Assault Guns and Tanks

The German 15-cm assault guns in N Africa made an impression on the British, and the first British SP guns (25-pdr on a Valentine tank chassis) were introduced with a similar role in view.  This was consistent with the generally inappropriate use of artillery in the 'pre-Montgomery' period in that theatre.  In contrast to the German and Russian armies British doctrine had never (apart from a flirtation in the 1920's) recognised any need for 'accompanying' artillery, basically the functions of such guns were undertaken by 'infantry' (I) tanks of the Royal Armoured Corps.  As noted above anti-tank guns were sometimes used in an assault gun type of role.

However, there was one exception..  This was the Royal Marines' assault gun regiments that landed in the first wave at Normandy.  These were equipped with 95-mm howitzers on Centaur tanks.  They were organised into batteries of 12 guns divided into 3 troops, with their troop commanders in Sherman tanks.  They were disbanded, according to plan, when the battle for Normandy ended, although one battery's worth was transferred to and used by the RCA for a few weeks.

From time to time in WW2 the British Army considered the introduction of 'infantry guns'.  A 95-mm infantry gun was developed but never entered service, probably due to infantry manpower shortages and RA opposition, "they'll just be left to guard the cookhouse" was the comment of one artillery staff officer.

Towards the end of the war some tanks also engaged targets with indirect fire as part of major fireplans.   They were issued with basic instruments to enable this.

NAVAL GUNFIRE

Land operations in coastal regions were widespread in WW2.  This provided many opportunities for fire from ships against shore targets, although enemy coast artillery was always a threat.  Destroyers, cruisers, battleships and monitors were used, as well as 'Landing craft, Rocket' in major amphibious operations.  A destroyer was considered the equivalent of a battery for planning purposes.  A naval officer and appropriately trained artillery officer were added to corps HQs operating in coastal areas.  Naval gunfire procedures differed from normal artillery procedures, therefore the observers had to be specially trained.

Initial attempts in N Africa were largely unsuccessful, the observer was in corps HQ and it took 24 hours to arrange a task.  However, RA Combined Operations Bombardment Units were formed.  These comprised troops of observation parties and RA liaison officers.  The LOs deployed aboard ships with a shore bombardment role.  The observation parties deployed on-shore and comprised an OPO/FOO and OPA trained in naval procedures and 2 naval ratings (telegraphists).  Each troop eventually had 7 observation parties and a similar number of LOs.  In amphibious operations a troop was usually allocated to each assault division.  Naval gunfire support first proved its worth at Salerno where it was used extensively, not least because there were no enemy coast artillery batteries and a shortage of allied airfields within easy range.

One allied naval bombardment method reported by the Germans in NW Europe was for aircraft to drop 'window' (radar reflective foil strips) over the target, this enabled the ship's fire control radar to range the target.  At D-Day artillery surveyors were among the leading elements and their first task was to erect marker beacons on known points so that bombardment ships could 'fix' their position and accurately attack targets on shore, particularly before the heavier artillery was landed.

AIRPOWER

In terms of firepower there are two aspects to air power: first the role of airborne target acquisition and second, and far more extensively, delivering firepower.  Air delivered firepower has significantly different characteristics to artillery, they are complimentary not alternatives.  One key characteristic is that in WW2 air delivered weapons were 'direct fire', someone on the aircraft aimed directly at the target.  This meant there were significant differences to indirect artillery fire.

Air observation of artillery fire was practised in the summer of 1913, many lessons were learned and in early 1915 a heavy battery commander directed his guns from an aircraft.  Later in 1915 the 'Zone Call' system was introduced, see the 'Artillery Intelligence and Counter-Battery' page.  During WW1 every corps had a reconnaissance squadron of the Royal Flying Corps (RFC) whose role was target acquisition and engagement using artillery fire. They proved very effective despite the limitations of available technology, notably ground to air communications - there were radios but they were scarce, signal lamps, coloured flares and message dropping were also used.  In this early period the Army tended to view the RFC as 'just another arm' and handle it accordingly, typically by allocating squadrons to divisions and corps.  

However, in 1918 the Royal Air Force (RAF) was created as an independent air force.  Army support was not a notably high priority for the new service as it battled to establish itself in a post-war period of financial stringency, with the added complication that the new RAF was developing its airpower doctrine.  This emphasised both centralised command and centralised control, which did not fit well with the Army's way of working with decentralised control.  In essence strategic bombing was the offensive priority, perhaps understandably for a new service keen to justify its existence and influenced by the writings of airpower protagonists.  Nevertheless the use of air power to enforce imperial rule was developed on the NW frontier of India and in Iraq as an alternative to ground operations.

Between the wars collaboration between the army and air force developed in two ways:  the formation of army cooperation squadrons and the development of 'Arty/R' procedures.  Close air support procedures were not well developed in this period.

Artillery/Reconnaissance (Arty/R)

The original concept of the Arty/R procedure enabled a passing RAF aircraft to call for artillery fire on any target that it saw, in essence the 'Zone Call' of WW1.  However, Arty/R was primarily the role of the army cooperation squadrons with their Lysander aircraft.  The procedures were detailed and included the amount of ammunition to be used on different types of target.  Significantly the pilots reported their observations of the fall of shot instead of the artillery practice of ordering corrections.   The campaign in 1940 seems to have demonstrated that the Lysander lacked the agility to survive in the forward areas against hostile fighters, although there appear to have been a few successfull shoots.  Arty/R does not seem to have been used in N Africa.

 The first problem was communications, RAF aircraft had VHF wireless with frequencies around 110 MHz while army wireless were HF operating below 10 MHz.  The solution to this problem was to provide all artillery regiments with at least one VHF receiver with RAF operators.  Communications from ground to air also used marker panels.  By 1941 the RAF operators seem to have disappeared but most field, medium and heavy batteries were supposed to have a radio for ground-air communications.  At some point this too was abandoned and the RAF undertook to equip some aircraft with No 19 sets, see the  'Artillery Communications' page.  However, in 1943 Arty/R was resurrected by the Tac/R squadrons in N Africa, led by 40 Sqn SAAF and continued in Italy.  Conditions in Italy, a succession of static fronts, proved well suited to Arty/R, but not the original concept of 'passing aircraft' being able to call for fire.   There was some use in NW Europe but conditions were less suitable and an apparent lack of RAF enthusiam.

However, trials had demonstrated that it was possible to automatically re-broadcast between a No 19 set and a RAF VHF two-way wireless connected together on the ground.  This meant that an aircraft could potentially talk to any battery.  Each AGRA and divisional HQRA had 2 of these installations for deployment as required. The value of Arty/R was that it could operate over enemy held territory and so acquire and engage deeper targets for medium and heavy guns.

 Nevertheless even given a reasonably practical air to ground communications system there was still the second problem, the difficulty aircrew had in locating targets on the ground with sufficient precision for artillery purposes.  The 10 yard accuracy required for predicted fire was out of the question, not least because aircrew tended to use inappropriate scale maps.  The Arty/R procedures were found to be impractical and over complicated.

The result was a new procedure, the 'Agreed Point Method'.  This meant that every shoot was planned in advance, pilot and guns both knew where the opening rounds were to fall, on features clearly visible from the air used as reference points.  The pilot then ranged them onto the target.  Arty/R became specifically planned missions against previously selected targets in some depth. However, these Arty/R aircraft often needed a fighter escort even when the air situation was satisfactory.   The Arty/R procedures were simplified in other ways as well.  Successful Arty/R engagements seem to have been most common in Italy.  Their great merit was being able to operate in some depth beyond where AOPs could fly, particularly in a CB role, and despite the challenges managed to successfully identify and engage 'guns firing now' targets during major operations.

Air Observation Posts (AOP)

The Royal Artillery operated balloon observation sections until 1937, and kites had been used in WW1.  From the mid 1930's several officers had identified the potential for AOP using light aircraft and had learned to fly at their own expense.  However, the RAF's commanders, having battled unsuccessfully to prevent the re-emergence of the Royal Naval Air Service, were unenthusiastic about the Army creating its own 'private air force'.  

Eventually the Army prevailed, and handful of aircraft went to France in 1940 but did not engage any targets.  The first AOP pilots' course was in late 1940 and the first squadron formed in August 1941.  It went into action in Tunisia about 16 months later.  A total of 12 British and 3 Canadian squadrons were formed.  These were RAF (and RCAF) squadrons, but the commander and all pilots were artillery officers, there were 3 RAF officers or warrant officers in administrative positions.   As RAF squadrons they 'belonged' to a RAF Group but were placed under operational control of army formations.  There was no tactical air command structure above squadron level, although at HQ 21 Army Group there was a general staff officer responsible for AOPs on the artillery staff.  The AOP role was to direct fire and report information.

The normal allocation was a squadron per corps plus one per army, this enabled a flight per forward division and AGRA.  At the end of the war squadrons were being organised into wings, with one assigned to an army.  However, in Burma there was a solitary squadron supporting 3 corps.

Each squadron had 16 aircraft and 19 pilot-observers, organised into 3 flights each with 4 sections of a single aircraft and pilot.  These sections each had two vehicles and ground crew (2 × RA) and aircraft fitters (2 × RAF) and could deploy independently.  Squadron HQ included a servicing flight with a workshop and a mobile maintenance party.  HQ flight comprised 4 spare aircraft with 2 pilots in addition to the Squadron OC (a major) and the Squadron Captain.  There was also 2 RAF administrative officers and an RAF engineer warrant officer.  

In summary the total establishment (WE II/126/4 effective 3 Nov 1943) was as shown in the following table (RAF ranks and details not known), there were no REME or ACC and most of the RA tradesmen were driver-operators.  Interestingly there was no Squadron Serjeant Major, although there was a sergeant in each flight HQ: 

The aircraft was the Taylorcraft Auster in various marks, with Mark IV and onwards being able to carry a camera and take air-photographs.  They required an airstrip of about 250 yards and were normally sited close to the artillery HQ of the formation they were supporting.  The usual radio was a No 22 set, which was also used on the ground at section, flight and squadron level.

The primary role of the AOP was to control artillery fire, usually the pilot acquired his own targets, and the Auster's excellent rearward visibility often enabled him to acquire a target that thought he had 'gone past'. This was further enhanced in late 1944 when the newest mark of Auster accommodated a rearward facing observer.  However, AOP also undertook other tasks such as route reconnaissance and reconnoitering future gun areas.  On occasions they also controlled mortar fire and naval gunfire, and were able to operate from aircraft carriers.  

 Casualties were surprisingly light, although in NW Europe it was necessary to establish early warning links to the local AA Operations Room.  As the pre-war proponents had foreseen the small, slow moving and highly manoeuvrable Auster flying at low altitude was an extremely difficult prey for fighters.   Enemy AA gunners quickly learnt that shooting at AOPs was not a good idea because they had a lot of clout.  However, their doctrine included several defensive measures, although when the threat was low they were not always applied:

• Pilots were trained to carry out a normal shoot in 8 minutes, something that was only possible given the emphasis placed on fast shooting by the guns.
• AOP were not to fly within 2000 yards of known or suspected enemy positions.
• Aircraft were to fly at the lowest level from which they could observe, but were not to fly more than 600 feet above ground level.
• A battery supporting an AOP had to post an air sentry within voice distance of a radio having communications with the AOP to watch for hostile aircraft.

The availability of AOPs meant that there was seldom any need for artillery officers to take to the air in aircraft piloted by others, although it happened occasionally.  For reasons that are unclear Australia did not form AOP units in the SW Pacific.  However, observation and artillery fire control was undertaken by RAAF crewed aircraft, mostly Wirraway but some Austers and other types were used, in army cooperation units.

The final target acquisition from the air was standard aerial photographic reconnaissance and air photographs were recognised as essential for really effective CB fire.  Each corps had an air photograph interpretation section and a counter-battery section  from the corps artillery CB staff was added to this at the beginning of 1944.  This section had direct wireless communications to the Air Liaison Section at a supporting wing.  The procedures for tasking aircraft and receiving photographs were fast and efficient.  This meant that air photography became an important source of target intelligence, although it was one that was vulnerable to deception measures such as dummy positions.  Nevertheless in static conditions photographic coverage of the area could be built up of time and differences that indicated enemy positions identified.

Offensive Support

 Tactical close air support of the army was not well developed at the outbreak of war, particularly when compared to German arrangements.  Furthermore it would be fair to say that in 1939 the Army did not understand airpower, despite the RA's investment in AA units.  The British protagonists of armoured warfare envisaged tanks supported by aircraft, the concept adopted by Germany as blitzkrieg, but the British didn't have the aircraft.  However, there was general acceptance that airpower could replace heavy artillery, particularly in its depth fire role.  In part this reflected the view that heavy artillery would be unable to keep pace with mobile operations.  In the event 1940 taught that heavy artillery was acceptably mobile, but it remained the lowest field artillery priority.  The shortage of medium and heavy artillery in the Western Desert meant that airpower was critically important there.

There was a wide variety of air-delivered munitions that could be used for battlefield support: MGs, cannon, rockets and bombs were the main air delivered munitions.  Bomb fuzes were usually instantaneous or delay but airburst was also available.  The UK started WW2 with 'General Purpose' (GP) bombs but early in the war switched to 'Medium Capacity' (MC), with about 40 - 55% of the weight being explosive.  High Capacity (HC) bombs with about 80% HE were also introduced but high blast effects were probably less than ideal for battlefield use and limited to use against fixed defences, similarly incendiary bombs were also little used on the battlefield.  Later in the war 5-inch rockets were used extensively for ground attack, and were also used from surface launchers - 'land mattress' by artillery in 1945 and from 'Landing Craft, Rocket' at D-Day and other amphibious assaults.  The HE bombs were:

Trials of new methods for controlling and integrating airpower into the land battle were held in UK in late 1940 with the RAF's Army Co-operation Command. This command later merged with Fighter Command.  The concept was used and matured by the Desert Air Force in North Africa, most notably after Montgomery's arrival and the increased availability of suitable aircraft, and resulted in a system adopted in other theatres.  This system applied to reconnaissance as well as offensive support.  It depended on the RAF providing a 'tactical air force' to support the Army.

The basic arrangement was a joint army and air force system.  The army identified targets for attack and submitted requests via an air support 'tentacle' to a joint army and air force HQ called a Army Air Control Centre (AACC).  Tentacles, comprising a R Signal communications detachment and Air Liaison Officers (ALO), deployed with brigade, division and corps HQs.  Within a corps all radios were on the same frequency, as was a radio in the flanking corps HQ (ie an Army level AACC had radios for each of its corps).  Requests went from the originating HQ to the AACC, intermediate HQs heard them but did not need to approve them ('silence means consent').  The ALOs were specially trained army officers from any regiment or corps, in 1944 they became staff officers (eg GSO 3(Air) at brigade level) and the 'tentacles' became  entirely R Signals.

The AACC (usually at corps/group or army/tactical air force level depending on the theatre), decided which targets would be accepted for attack, and selected the wing for the task and issued the orders.  The wing HQ nominated a squadron which was then briefed by its local Air Liaison Section.  Response times varied widely, in some conditions it could be less that 45 minutes in others it could be the next day.  The communications network - the 'tentacles' - was provided by special R Signals regiments eventually called 'Air Support Signals Units' (ASSU,  initially Close Support Bomber Control then Army Air Support Control units).  ASSU tentacles also provided communications on a frequency that broadcast the short 'written' summaries of the debriefing reports from Tac/R pilots.

However, in Italy from mid-1944 an additional system emerged, initially called 'Rover David'.  These Rovers, small parties comprising army and air force officers with both army and aircraft communications, controlled 'cab-ranks' of ground attack aircraft in the air. Where the tactical situation was suitable a Rover would deploy with a cab-rank available for perhaps 2 or 3 hours.  Air requests would then be sent to the Rover which, if it accepted them, would assign the task to aircraft in the cab-rank and brief their pilots.  This was the difficult bit.  The method used was for both Rover and pilots to have a common set of air-photographs marked with a reference grid.  Using these the Rover could brief the pilot where the target was.  A similar cab-rank procedure was used from time to time in Burma where the controllers were called 'Forward Area Control Posts', although the generally longer distances from airfields to target meant that there was not much time available to stay in a cab-rank.  In NW Europe where they were called 'Forward Control Posts' with one assigned to each army and typically allotted to its leading corps.  The RAF officer was called a Forward Air Controller (FAC).

Coordinating ground attack aircraft was a major challenge, it was all too easy for pilots to wrongly identify targets and attack friendly troops.  From Normandy onwards heavy bombers were also used for 'close' support of the army, further exacerbating the control and coordination difficulties.  In the desert air support was relatively easily coordinated with fireplans because the pilots could see the artillery fire and attack targets beyond it.  After that it got more difficult.  White and coloured smoke fired by artillery could be used to mark a line beyond which aircraft could attack targets and coloured flares were used at night to guide heavy bombers, although there still had to be a safety distance of many thousand yards between their target and forward troops.  In one operation in 1945 in Italy HAA fire bursting below the aircraft's planned altitude was used to mark the fly line for heavy bombers.  The ASSU eventually provided Visual Control Posts (Air Contact Teams in Europe), with a FAC, deployed forward (often with a FOO) with communications to aircraft were also used to control ground attack aircraft in close proximity to friendly troops.  

Finally it is useful to highlight the differences between offensive airpower and artillery:

• Aircraft could deliver munitions far behind the enemy's forward troops.
• Aircraft could routinely deliver large munitions.
• Artillery could deliver and sustain continuous attacks lasting many hours.
• Artillery could improve and maintain the accuracy of its fire as its attack continued, for aircraft every attack by every individual aircraft required the crew to acquire the target and aim directly at it.
• Artillery could control the position of the mean point of impact of its fire to reflect the needs of the supported commander and the actions of the target while fire was in progress.
• Artillery could quickly change the type of ammunition being used against a target.
• Artillery could get shells into their target area within a few minutes at most after being 'called'.
• Artillery could attack targets '24 × 7', no matter what the weather or visibility.
• Artillery commanders were fully integrated with infantry and armoured forces.

The first is most significant and its 'reach' went far beyond the areas normally considered by Army planners.  It raised the problem of priority between close and deep targets, the common conundrum being that in the greater scheme of things the important targets were seldom urgent and the urgent ones seldom important.  Of course the front line infantry always had a very clear idea of what was important and urgent!

 Copyright © 2002 - 2014 Nigel F Evans. All Rights Reserved.