Airfield defence during the Phoney War was in reality limited to anti-aircraft defence. During April 1940 there was a growing realisation of the threat posed by air landing and parachute troops. It was considered the best way to meet this threat was with maximum use of light automatics, covered by wire entanglements, to sweep the aerodrome with a heavy volume of fire, including AA guns being given a secondary ground defence role. It was recognised that a Station could not be defended from the inside, the light automatics had to be sited to cover the aerodrome and the outside approaches. Provisions for a mobile force of light automatics mounted on vehicles and a relief force was also considered necessary.
During the summer of 1940, Maj-Gen G.B.O Taylor, Inspector of Fortifications, was tasked with formulating a defence policy for airfields against the most likely form of attack. He laid out the probable nature and scale of attack as follows:
Phase I - Heavy scale dive bombing and machine gun attacks on airfield defence posts and buildings. These attacks would be carried out around the perimeter of the airfield as well as the central buildings.
Phase II – Parachute troops of about 500 per airfield equipped with rifles, grenades, light machine guns and mortars. Parachute troops would land outside the airfield and form up into groups of about 100 before attacking. Some may land on the airfield itself.
Phase III – airborne troops landed on or off the airfield, possibly equipped with light field guns, motor cycles and side cars and light tanks. Aircraft after landing would likely taxi to the airfield perimeter to allow further aircraft to land.
Phase IV – after capture of the airfield, enemy fighters might use the airfield to provide local fighter cover.
Taylor realised that not all airfields were equally likely to be attacked. As a result he proposed a classification of airfields as follows:
Class I – aerodromes subject to the most intensive attack These would be aerodromes essential for the enemy to capture to support a landing on beaches as a preliminary attack on a port. Class I airfields were then all those within 20 miles of a major port. In Suffolk the relevant ports were Lowestoft and Harwich, making Martlesham Heath and Wattisham with its satellite Ipswich, Class I airfields.
Class II – aerodromes subject to intensive attack but confined to air and parachute attack. These included Fighter and Bomber Command Stations which could attack and defeat seaborne landings (Class II(a)) and aerodromes near Vulnerable Points (Class II(b)) or Airfield Storage Units (Class II(c)) that were considered to be likely enemy targets. Class II airfields in Suffolk were Honington, Mildenhall and Tuddeneham which was under construction.
Class III – aerodromes that may be subject to light air attack or small scale parachute attacks with no obvious tactical objective but as a diversion or nuisance. Basically all other aerodromes not in Class I or II. Phase III of any attack was considered unlikely at Class III airfields.
To meet any attack, Taylor decided the defence must be organised in three zones – upwards, inwards and outwards. Defence posts would have to be dispersed around the airfield to cover both the perimeter and the landing ground. Overhead cover and camouflage of defence posts was vital. Posts would have to be mutually supporting. AA defences should be co-ordinated with ground defence as they could assist the latter if they had no air targets to engage. An all round wire obstacle was required for the perimeter and local wire obstacles for each post. Two or three disappearing pillboxes, which had just been designed, were to be located near the centre of the aerodrome. Finally, each airfield should have a relief force assigned to it, which could reach the airfield within one to two hours.
Taylor stated it was a waste of resources to equip every airfield with defences to repel any scale of attack. Hence he proposed a scale of defences for each Class of airfield.
A series of concrete or brick pillboxes on or near the perimeter, no more than ½ a mile apart, designed to cover the aerodrome surface with light automatic or rifle fire (considered to be between 8 to 14 pillboxes depending on the length of the perimeter).
A second series of pillboxes sited to cover the external approaches to the aerodrome and dispersal points which could be reasonably included in the perimeter defence plan (considered to be between 12 to 18 pillboxes depending on the length of the perimeter).
Three disappearing pillboxes were also recommended.
As well, a series of prominent dummy pillboxes should be constructed (10 to 12 was considered suitable).
Rifle pits with overhead cover should be constructed around the hangers and station buildings for the rest of the garrison. Mobile improvised vehicles with light automatics should also be available.
It was estimated that 274 troops would be required to man these defences. Rifles would also be provided to station personnel as well.
An allocation of American .300 Vickers machine guns was also made for airfield ground defence at about 20 guns per airfield and 16 guns per satellite for all Class I airfields. The guns were to be sited in emplacements with at least splinter proof head cover and preferably bullet proof cover. Dummy emplacements were to be provided as part of the camouflage scheme. At some airfields, pillboxes were constructed for the Vickers guns.
Above: Map of Wattisham - a Class I airfield. As Mike Osborne has noted it would appear that the scale of pillboxes laid out in the Taylor Report where never actually provided at any airfield.
Defences as for Class I airfields but a 25% reduction of pillboxes (i.e between 6 to 10 pillboxes for inward defence and 9 to 14 for outward defence) and no disappearing pillboxes. Also a 35% reduction in armoured vehicles. Also a reduced scale of American .300 Vickers machine guns.
It was estimated that about 225 troops would be required to man these defences.
A single ring of pillboxes was considered adequate (between 10 to 16 pillboxes depending on perimeter length). No armoured vehicles or disappearing pillboxes were to be provided. Also a reduced scale of American .300Vickers machine guns.
It was considered that about 191 troops would be required to man these defences.
The Taylor Report was accepted in principle by the Air Council and Army Council and was to be regarded as the standing instruction for airfield defence. However the classification of airfields was modified to reflect distance from the coast and not just a port. The new classifications were:
Class A – all airfields which may be subject to airborne or seaborne attack in direct assistance to an invasion or those that may be liable to a raid as a separate operation or in conjunction with an invasion. For this, all airfields within 20 miles of the coast south of a line joining the Wash to the Severn, those within 20 mile of Hull, Middlesbrough, Newcastle and Edinburgh and all Fighter aerodromes in the UK exclusive of those in Western Command.
Class B – all airfields containing aircraft factories or M.A.P. establishments.
Class C – all other airfields.
The Field Army was to provide the garrison for Class A and B airfields (with a scale set at 217 men and 130-280 men respectively) while the RAF was to be responsible for the defence of Class C airfields (with a scale set at 120 men).
This method of classification did cause some concern – Air Commodore Sanders noted that as the main attack on airfields was to be by airborne troops the classification according to distance from the sea was “absurd”. By the summer of 1941, it was recognised that circumstances had changed since the Taylor report was produced. The distance from the sea was no longer the decisive factor in determining the risk to airborne attack. Also the situation with reserve aircraft had improved – in the autumn of 1940 the destruction of reserve aircraft would have severely reduced RAF operations but this was no longer the case.
The most likely use of German airborne troops against aerodromes was now considered to be:
Large scale raids on Fighter aerodromes to cripple Fighter defence.
Heavy scale attacks on aerodromes near the coast with the objective of seizing bridgeheads for a seaborne invasion.
The Chiefs of Staff revised the priority for airfield defence as follows:
Priority I – Fighter stations and satellites in East Anglia and South East England.
Priority II – Fighter stations and satellites south of the line Wash-Severn (excluding priority X).
Priority III – Fighter stations and satellites in the area Wash- Birmingham-Newcastle-Wash.
Priority IV – M.A.P aircraft storage units and satellites south of the line wash-Severn.
Priority V – Aerodromes other than Fighter within 20 miles of the coast south of the line Wash-Severn, and within 20 miles of Hull, Middlesbrough, Newcastle and Edinburgh.
Priority VI – M.A.P. aircraft storage units and satellites north of the line Wash-Severn.
Priority VII – Fighter stations and satellites north and west of the line Severn-Birmingham-Newcastle.
Priority VIII – Operational and training aerodromes within 20 miles of the East Coast and north of the line Wash-Severn (excluding priorities V and VII).
Priority X – All other aerodromes wherever situated.
The defence policy of aerodromes also shifted from Taylor’s scheme of rings of pillboxes to platoon posts sited for all round fields of fire and mutually supporting. Posts should be sited to facilitate control but not too concentrated that one bomb could destroy more than one post. Posts were to be camouflaged. RAF personnel were also to be allotted an area to defend – usually the aerodrome buildings. Defence posts were to embrace the landing ground and as many installations as possible. Remote dispersal aircraft pens were not to be included.
Right: 11 Corps Scheme for Airfield Defence - based around
platoon posts rather than rings of pillboxes.