Maintenance Developments

The Aircraft Maintenance Organisation in France and the Low Countries, September 1939 to June 1940

It was decided in 1927 that the organisation for the maintenance of a RAF Expeditionary Force would, during the early stages of a European campaign, be of a mobile character. In consequence the establishments of squadrons in personnel, mechanical transport and stores would have to be kept down to the absolute minimum, and as a means to this end the squadrons would be relieved of all repair work. It was proposed that squadrons would carry a three days' supply of spares only, but behind the squadrons and within 25 miles approximately of them a number of mobile Air Stores Parks would be provided, each carrying one month's stores for the units they served. Behind the Air Stores Parks it was intended to organise a non-mobile Aircraft Depot holding anything up to a six months' stock of spares, etc., for the force and providing for the repair of airframes, engines and mechanical transport. When moves of the squadrons were frequent it was proposed that they would not normally undertake maintenance which would take more than four hours to complete, and work beyond this capacity would be undertaken by advanced repair detachments sent forward to the vicinity of the squadrons from the base repair depot. Tasks incapable of being performed by these sections would be returned to the depot.

As the progress of the 1939-1945 war eventually showed, the principles of this scheme of maintenance for an expeditionary force were sound, but in 1931, when the various departments of the Air Ministry concerned were engaged in working out the details of the organisation, the proceedings were interrupted by the Director of Organisation and Staff Duties who proposed that squadrons forming part of an expeditionary force should be provided with sufficient personnel, equipment, stores and spares to enable them to be self-supporting, and consequent upon this change in the proposed war organisation the establishments of the repair and maintenance organisations at the base and on the line of communication should be reviewed.

The proposals were put before the Chief of the Air Staff in May 1932 by the Deputy Chief of the Air Staff (Air Vice-Marshal C S Burnett). DCAS said that he was not at all convinced that the proposal to abolish advanced repair facilities and substitute repair sections in squadrons was sound. He considered that in war it was most important that squadron commanders should be freed from the restrictions of maintenance and their clogging effects on mobility. The Chief of the Air Staff agreed on 6 September 1932, after considerable discussion, to leave the 1927 war organisation as it was for a period of two years, by which time he hoped that more experience on the subject of advanced repair sections would have been gained.

The air forces destined for transfer to France in the event of war were in two distinct entities, possessing clearly separate functions - the Advanced Air Striking Force and the Air Component of the Field Force. The former was to be a bomber force only, comprising squadrons of Bomber Command based in France because of the comparatively short range of their aircraft. The Air Component, on the other hand, was a mixed formation designed as an integral part of the Army Expeditionary Force for which it was supposed to supply air reconnaissance and protection. It thus consisted of aircraft for bomber reconnaissance, strategical reconnaissance and tactical reconnaissance work, together with some fighter squadrons, all of which, through the AOC Air Component, were under the operational control of the Commander-in-Chief, British Expeditionary Force. In addition to these air formations, two air liaison missions were also scheduled to proceed to France. No I Air Mission was to represent the Chief of the Air Staff at the Headquarters of General Vuillemin, the Commander-in-Chief of the French Air Forces. No 2 Air Mission was to represent the Air Officer Commanding-in-Chief, Bomber Command, at the Headquarters of General Nouchard who commanded the French Air Forces on the North-East front.

The 'Western Plan' for a war in Europe provided for the Advanced Air Striking Force to proceed to France in two echelons. The first echelon was to be No 1 Bomber Group with its ten squadrons organised into five wings. The second echelon, to follow some eighteen days after the first, was to be No 2 Bomber Group with a similar number of squadrons and organisation. It was intended that the Headquarters of No 1 Bomber Group, with an increased establishment of personnel, should function as Headquarters, Advanced Air Striking Force, until the second echelon arrived in France, after which both Nos. 1 and 2 Groups would come under HQ, AASF

This plan was in the early stages of organisation when the September 1938 crisis started a more hurried preparation. In that crisis the Air Officer-in-Charge of Administration designate for the AASF and a small staff were sent with a War Office staff to make a reconnaissance in France and to supplement arrangements which had been made previously between the two Air Ministries. One of the results of this mission was to stock selected aerodromes in France with bombs, ammunition, petrol and oil prior to the war.

Included in the plan to send the AASF to France was a ' Quick Despatch Scheme' in which provision was made to fly to the allotted aerodromes on the Continent a' Servicing Flight Section' for attachment to each of the five wings to be ready within 24 hours of their arrival for the maintenance of aircraft until the main bodies of the squadrons arrived. In addition, arrangements were made for a French 'Air Company' to be installed on each aerodrome to receive the squadrons and to provide certain essential services until our administrative and supply organisation was complete. Apart from these arrangements for the initial period of the AASF the maintenance project for both this force and the Air Component rested upon the squadrons, who in accordance with the decision of 1934 were alleged to be established for all routine inspections of their own aircraft and mechanical transport and for the carrying out of repairs occupying not more than 200 man-hours. Complementary to this squadron organisation were three Air Stores Parks for each force to which were attached special sections for supply and transport, for salvage and for railhead handling. Finally there was No 21 Aircraft Depot at the base which was planned to carry out major repairs up to 400 man-hours, the reissue of repaired engines and airframes to the squadrons, and the holding of equipment to meet all the needs of the Royal Air Force in France.

The Advanced Air Striking Force moved to France before the Air Component. Both forces were mobilised before the war commenced and the executive order for the move of the former was given [on the afternoon of] 1 September 1939. At dawn on 2 September the servicing flight sections left by air for the Continent in civil aircraft which also carried kits and essential stores. They were followed by the air part of the Headquarters of the AASF, under Air Vice-Marshal Playfair, and then by the squadrons themselves. When the squadrons arrived they were refuelled and bombed up by the servicing flight sections and were ready for operations by the time war was declared on 3 September. Apart from this, however, many difficulties were experienced and had operations been commenced immediately it appears doubtful whether the squadrons could have remained efficient for any length of time. With one or two exceptions there were no permanent buildings on the French aerodromes, which for the most part were remote from all save tiny villages. The absence of the bulk of the transport in this stage was thus acutely felt and the billeting arrangements proved awkward. In the case of No 71 Wing the French Air Company was quite unprepared for the arrival of so many personnel and no arrangements had been made for the accommodation and feeding of the majority. The organisation as laid down in the aerodrome dossier was practically non-existent. Two tents only were provided on the aerodrome, one of which was occupied by the French guard. Three petrol filling points were available but two of these became unserviceable soon after they were used. The other Wings experienced a similar situation in varying degrees and No 74, in particular, had many complaints to make. The Wing operation record book states that on the arrival of their squadrons it was found that the French Air Company had made no arrangements at all for the reception of the formation, apart from the installation of a highly inefficient telephone system. From 2 to 9 September the entire time of all the officers of the Wing was devoted to the constant struggle with the administrative problem due to the complete breakdown of the organisation, which should have been available for the accommodation and feeding of the troops.

The arrival of the main bodies of the first echelon of the AASF, which took place between 13 and 19 September, also suffered from inadequate planning. the despatch of the mechanical transport appears to have been unduly delayed, and the AASF Headquarters operations record book speaks severely of this aspect of the move. Considerable difficulty was experienced during unloading operations and in the despatch of vehicles from the ports. Little organisation existed and no arrangements whatever had been made for feeding the personnel other than through the imprest account of the embarkation staff at St Nazaire. No facilities were available for guiding vehicles to their destination, and no instructions were issued for refuelling, staging or billeting. The safe arrival of the convoy was entirely due to the resourcefulness of its personnel and the extreme helpfulness of the French civil and military authorities.

In the absence of immediate operations the servicing flight sections were fortunately not called upon to do a great deal in the early stages otherwise the flaws in their organisation would soon have placed them in difficulties.

The second echelon of the AASF did not arrive in France according to plan. This was due to the fact that although arrangements had been made with the French for ten aerodromes with ten satellites to be provided for the force in order that not more than one squadron should occupy each airfield, the first echelon found on arrival that the satellites had not been prepared. In the interests of adequate dispersion as a protection against enemy air attack the first echelon decided to occupy the ten aerodromes instead of restricting themselves to five. This arrangement enhanced the maintenance difficulties as the wings had been designed to handle two squadrons on one aerodrome and the number of transport vehicles provided was insufficient to meet the additional requirements involved.

The transfer across the channel of the Air Component, under the command of Air Vice-Marshal C H B Blount, did not take place on a single day. Being related to Army movements the move was spread over a period of 5½ weeks, from 4 September to 12 October. The arrangement was for the ground parties of the squadrons and Wing Headquarters of each wing to proceed some four or five days in advance of the aircraft and crews in order to be prepared to maintain the aircraft on their arrival and for the main rail and road convoy parties of the squadrons to join their advanced sections a few days later. Unfortunately, however, owing to the lack of detailed planning and the incorrect routeing of vehicles, the rail parties arrived at their destinations several days before the road convoys turned up with the equipment (In the case of No 50 Wing there was a delay of 13 days.). Not only was considerable inconvenience caused to squadrons through lack of transport but the men suffered much hardship because blankets and other essentials were not forthcoming immediately.

No 21 Aircraft Depot experienced every kind of difficulty. When mobilisation of the depot commenced it was found that there was not sufficient equipment and skilled personnel available to organise it to perform its intended functions. In consequence of this it was decided to establish it in an attenuated form, which meant that the equipment section, instead of being a holding unit, acted only as a transit pool, and the various repair and salvage sections could deal with nothing more than work of a minor nature.

When the depot, under the command of Group Captain McCrae, arrived in France it found no adequate accommodation for its work because the hangars allocated were not vacated by the French until the beginning of November. Equipment arrived with no means of unpacking it and nowhere to store it. The depot personnel had to be employed on erecting Bessoneau hangars and tentage, making roads, constructing drainage and carrying out a general struggle for existence. Few sites were available for the various sections and much of the ground turned out to be unsuitable. As late as the first week in January, personnel were still living in tents. Moreover, even the administrative status of the depot was unsatisfactory. Intended to serve both the AASF and Air Component, it was administered by the former.

The failure to establish a base depot capable of providing for the needs of the air forces reacted on the efficiency of the Air Stores Parks. The parks arrived in France stocked, according to plan, with one month's supply of equipment. They were then mobile. When it was found impossible to make No 21 Aircraft Depot a stores holding unit, the parks were maintained direct from the United Kingdom and under these conditions their holdings had to be increased from one to two months' supply. The mobility of the parks then almost completely disappeared.

Before the Air Stores Parks were established all non-technical supplies and rations were obtained from French sources, either by purchase or transfer. Units dealt direct with their home stations for technical equipment and such equipment was flown out. Petrol for aircraft and mechanical transport was obtained locally from French Army sources.

On 10 October a small detachment of engineer and equipment officers arrived by air at GHQ, British Expeditionary Force, for liaison duties. This detachment was known as 'Q' RAF. It was posted to the Air Component for purposes of RAF administration and attached to 'Q ' (Maintenance) GHQ, BEF, for duty. The responsibilities of Q' RAF were

Meanwhile, the absence of suitable arrangements in the forward area for the repair and salvage of aircraft outside the squadrons compelled the AASF to take steps to remedy the deficiency. The solution adopted was the formation of Repair and Salvage Units, each comprising a mobile repair section sent up from No 21 Aircraft Depot, and a railhead handling party and three advanced salvage sections previously attached to the Air Stores Parks. These Repair and Salvage Sections were made responsible for repairing or salvaging all aircraft crashed or forced landed away from their squadron and for repairing aircraft beyond the capacity of squadrons. Damaged aircraft which would be patched up for one flight to the United Kingdom for subsequent repair were so treated; while all airframes and engines beyond the capacity of the Repair and Salvage Units to deal with were to be sent to No 21 Aircraft Depot, although this was, in fact, in no position for many months to undertake the work.

On the supply side, adjustments were made to certain sections of the Air Stores Parks to place them on a geographical basis so that they could more easily meet the demands of the squadrons in their areas. Petrol and oils were distributed by the Supply and Transport Sections attached to each park. The plans drawn up prior to the war envisaged petrol and oils being drawn by units direct from railheads. In practice, however, it was clearly seen that to supply continuity and to guard against breakdown of the lines of communication it was necessary to form reserve dumps forward of railheads and in the rear of aerodromes. These dumps were located adjacent to the parks and their maintenance proved an extremely heavy commitment to the S and T Sections of the parks which had not been provided with the labour and vehicles necessary for the work.

As a result of the first few months' experience in France it became clear that the organisation for repair and salvage, while it might serve for the very limited operations of the opening phase of the war, would be quite inadequate for a period of intensive operations. It was also clear that it was dangerous to overload the Air Stores Parks in the forward areas and render them immobile. In fact, the whole supply position would be considerably better if a full equipment holding section at No 21 Aircraft Depot could be developed as originally intended. To achieve these two ends the Air Ministry decided in December 1939 to form a Maintenance Control under a Maintenance Officer-in-Chief and with an appropriate staff. The new organisation was charged inter alia with the special task of developing No 21 Aircraft Depot and establishing more and larger repair and salvage units. Maintenance Control absorbed 'Q' RAF.

On 31 December 1939, Air Ministry instructions were issued for the formation of a Command under Air Marshal Sir A S Barratt to take over the British Air Forces in France with effect from 15 January 1940. When British Air Forces in France, came into being, therefore, the new Maintenance Officer-in-Chief had only just started work. The Maintenance Officer-in-Chief with his staff was then located in close proximity to GHQ and was too far away for the daily contact which the AOC-in-C. and his staff required, in order to keep in touch with the urgent problems of maintenance and supply. Consequently, on 29 February 1940, Air Marshal Barratt brought the MO-in-C's organisation over to his own Headquarters, leaving a Wing Commander at GHQ for liaison purposes.

The responsibilities of the Maintenance Officer-in-Chief were defined to the following effect: -

The Maintenance Officer-in-Chief also represented the Director General of Maintenance (Air Ministry) in France, dealt directly with Air Ministry on technical matters and was to pursue close contact with Maintenance Command; it was thus hoped that good co-ordination would be obtained between the maintenance organisation in France and in the United Kingdom.

At the time of the appointment of the Maintenance Officer-in-Chief no real start had been made towards building up the Equipment Holding Unit of No 21 Aircraft Depot, apart from the erection of some Bessoneau hangars. It had, however, been decided that the unit should be formed with an initial issue of six weeks' supply for the British Air Forces in France. By the end of January 1940, the equipment unit was being brought up to the necessary strength and some of the large Bellman hangars to house the stocks had arrived. A month later the erection of one of these was nearly complete, and the unit was in a position to issue items of equipment in the clothing section. As the depot reported readiness to issue in any particular section, so the holdings of the forward Air Stores Parks in those items were reduced and the necessity for the parks to draw stocks direct from the United Kingdom was avoided.

During February many of the sections of the Equipment Holding Unit were receiving items and by March about 175 tons of incoming stores were being handled each week. By the end of April it was prepared to receive from the United Kingdom all items of the 'Vocabulary' up to a six weeks' stock, and to issue, in France, clothing, barrack stores and MT spares. By 14 May - four days after the German attack opened the Equipment Holding Unit was at last in a position to issue items from all sections.

Side by side with the completion of the Equipment Holding Unit went the development of the repair and salvage facilities of No 21 Aircraft Depot. By the end of January some aircraft salvage had been carried out together with some repair of mechanical transport and construction of gun mountings. This was on a very small scale, however; very little repairable material had been returned to the United Kingdom, and it had not been possible to achieve any output of repaired airframes or engines. As the result of proposals made by the Maintenance Officer-in-Chief in February, within a broad framework previously determined at the Air Ministry, the following policy for the depot was then finally decided upon

This policy was not, however, issued with full Air Ministry authority until 27 March, and there was further delay in filling the new establishments deemed necessary; this in itself, apart from the other innumerable difficulties, made for slow progress. It was not until May that the engine repair section was in production on a small scale, three engines having actually been overhauled, while the airframe repair section at this period had managed to complete the repair of four airframes. The MT section was rather more advanced - 41 vehicles had been overhauled since January. The machine shop was almost ready to operate, but, in the absence of the long-deferred connection with the French electric mains, awaited a full quota of power-trailers. The armament repair section was working satisfactorily and had overhauled 38 guns. The salvage section had handled and classified 78 trucks of salved components during April and had reduced 20 airframes to produce. Forty-eight of the fifty-two repairable engines received from the forward areas during April had been sent on to the United Kingdom.

As regards the development of the Repair and Salvage Sections in the forward areas, the task to be faced was, in fact, probably more important than that happening at the base. It has already been mentioned that Repair and Salvage Units had been improvised from the repair, handling and salvage sections attached to No 21 Aircraft Depot or to the Air Stores Parks. The intention, as advanced by the Maintenance Officer-in-Chief and promulgated by the Air Ministry on 27 March, was that this impromptu arrangement should be confirmed and strengthened. To this end the amalgamation of the repair, handling and salvage sections into Repair and Salvage Units was to be regarded as permanent, and the sections were therefore divorced administratively from the Aircraft Depot and the Air Stores Parks which had originally been responsible for them. The RSUs were to be given more equipment, more MT and an increased establishment of personnel, and thus were to become sell-contained. It was considered that three of these units should function under the AASF and three under the Air Component; but owing to the greater estimated wastage in the Air Component, the RSUs with that formation were to possess a greater number of mobile salvage sections than those with the AASF The composition of a Repair and Salvage Unit was to be:-

The full development of these units was never completely achieved. A certain degree of progress was made but the full establishment of MT and personnel as approved by the Air Ministry had not been provided by 10 May, and when the German advance commenced the RSUs were still in a state of reorganisation. There were many other reasons for this delay, the most important being the shortage of equipment of one kind or another. A clear instance of this was the difficulty of equipping units with machine-tool trailers. These were to be released from No 21 Aircraft Depot, but the depot could not release them until its permanent machinery was installed, and the depot's permanent machinery could not be installed until a Bellman hangar to receive it had been erected. Thus an action which had been agreed on early in January was still not achieved in May. Similarly with the provision of power-trailers which were also to be released from No 21 Aircraft Depot; but the depot could neither get connected to the French power and light mains, nor could it secure other power-trailers in replacement if it surrendered its own.

Although the scarcity of equipment and our commitments in Scandinavia may have accounted for much, the Maintenance Officer-in-Chief was of the opinion that some of the delay in bringing the Repair and Salvage Units on to a operational footing was caused by the limitations of his own executive authority. Indeed, in the AASF there seems to have been some disagreement with the policy itself, for the reduction in the number of salvage sections in the new units is considered unwise. In fact, the AASF apparently did not attempt to give effect to the new establishment in this direction; and it appears that even though some five months had elapsed since the subject was broached there was in respect of it a lack of close co-ordination between Air Ministry, Maintenance Staff and BAFF Headquarters and the AASF.

Several additions were made to the supply arrangements. Reserve petrol dumps were established within 'lorry carrying' distance of railheads to ease the position created by the great length of the lines of communication. These dumps held 14 days' supply of all aviation and MT fuels and oils for the units they served. Forward Air Ammunition Parks were also formed for the same reason. The functions of the parks were: -

Lack of Mobility Resulting from Underestimation of Mechanical Transport Requirements

In the original organisation the Air Component was established to a greater degree of mobility than the AASF, for squadrons (but not ancillary units) were completely mobile in the former, while in the latter neither squadrons nor ancillary units were completely mobile. Supply and Transport Sections were attached to the Air Stores Parks of the AASF and were available for the general transport requirements of the force, but not in such strength as to render the whole force mobile at any one time. The early events in the life of the AASF also somewhat upset the organisation - in particular the decision to base not more than one squadron on each aerodrome - and in general the force found itself short of vans and cars for domestic needs. Something was done to alleviate this position by the local purchase of forty Renault vans in October, and the provision of a few buses in November. When the question of the insufficiency of mechanical transport vehicles was taken up with the Air Ministry the latter expressed the opinion that the force was not economically organised in 3-ton tenders, and the formation of BAFF Command and other reorganisation provided a suitable opportunity for a review of the whole transport position. In January 1940 arrangements were made for the Air Ministry Establishments Committee to visit France to examine the subject.

The intention of the investigation was announced beforehand by the Director of Organisation. It was 'to try to effect economy in MT pooling where possible, to ensure proper maintenance and also to adjust establishments to include more suitable types of vehicles'. Its aim was thus not to increase mobility but to effect the most economical organisation. The ideas with which the Committee began are contained in a paper which was sent in advance to AASF and BAFF Headquarters, and since the opening paragraphs of this paper contain a clear statement of the historical background on the degree of mobility considered necessary for the AASF they are quoted in full

"Owing to the strategical position of the AASF behind a strong fortified line, the degree of mobility required for the units is small. Although individual units may move from time to time, the movement of the whole force at one time is regarded as improbable. The AASF was organised, in the Administrative Plan, on a two squadron wing basis following closely on the home organisation. Most of the MT and administrative facilities were established on the Wing HQ and the squadrons themselves kept as small as possible. It was assumed that both squadrons of each Wing would operate from the same aerodrome. As regards the Air Stores Parks it was realised that any attempt to make them fully mobile would defeat its own object owing to the very large number of vehicles which would be required to put this into effect. It was therefore decided to keep only 50 per cent of the normal holdings of the Parks on wheels, and to establish sufficient load-carriers on the Headquarters to enable one of the three equipment sections to be made fully mobile at short notice.

Since the arrival of the AASF in France the following factors have contributed towards making the force even less mobile as a whole

It has now been decided on other papers that the AASF is to be reorganised on the system of small operational Wing HQs controlling three or four self-contained squadrons, as it has been found necessary for each squadron to be located on a separate aerodrome in a widely dispersed area.

In view of the foregoing, it is now proposed to adopt an administrative policy whereby the mobility of the AASF is limited to the moving of not more than four of the squadrons at any one time. To do this it is proposed to take most of the load-carrying vehicles from AASF HQ and the forward units, and to organise Wing MT Companies which will consist of load-carriers to be used to assist squadrons and other units as necessary.

The two fighter squadrons in the AASF are regarded in a different light to the bomber squadrons, and it is not proposed to reduce their mobility or include them in this reorganisation. They will, however, be able to obtain assistance from the Wing MT Companies if necessary owing to the length of their L of C"

With the formation of these two Wing MT Companies (each to be capable of serving four squadrons, one Air Stores Park and ancillary units) it was calculated that the existing Supply and Transport Sections could be abolished. Altogether it was hoped by these proposals to achieve a reduction of nearly 150 3-ton tenders with the AASF, and to use these principally to replenish the 15 per cent reserve holding in No 21 Aircraft Depot, which had been virtually exhausted. It was also hoped to apply similar proposals to the Air Component.

The Air Officers Commanding in France, while accepting the idea of pooling some of the heavy transport in Wing MT Companies, found it very difficult to agree to every detail of a scheme which would have considerably reduced the mobility of their forces. Air Marshal Barratt was by no means inclined to accept the proposition that the AASF was in a completely safe locality.

The AOC-in-C's views on the degree of mobility necessary were urged on the investigating committee at BAFF Headquarters on 5 February; and, according to his own statement, they were accepted. It was then left to the Air Ministry to produce their revised scheme.

On 25 February, the Air Ministry issued their proposed new establishments of MT, but the full scheme for its reorganisation was not yet forthcoming, nor were personnel establishments issued. Consequently, Air Marshal Barratt represented to the Air Ministry that the matter had now been under consideration for six weeks, and requested despatch of the scheme at an early date. The scheme was eventually issued by the Air Ministry on 8 April though without the personnel establishments for the new Headquarters MT Companies in the AASF.

The Air Ministry scheme listed, amongst others, the following conclusions on the existing position in France: -

The scheme therefore allowed for a large increase in light vans; the reduction of heavy tenders within squadrons to numbers which would enable them to move essential stores and personnel for 3 days' operations, or within other units to numbers necessary for day-to-day use; the introduction of MT pools in the Air Component on a Group, Wing and HQ basis; the introduction of three MT pools (explosives, fuel and general) under AASF Headquarters to serve the AASF bomber squadrons; the retention of the complete mobility of No 67 (Fighter) Wing and the splitting up of the 15 per cent reserve previously held at the base among No 21 Aircraft Depot, AASF and the Air Component.

It was reckoned that the general effect on mobility of these arrangements would be as follows: -

Squadrons. All squadrons could move their essential personnel and equipment at once with their own MT. Remaining personnel and equipment could be moved and the squadrons kept supplied with fuel and explosives by the MT in pools.

Air Stores Parks. Essentials for two weeks' consumption of two of the three parks could be moved by MT in the Headquarters pool.

Squadrons. Fighter Wing HQ and two squadrons would be completely mobile. Bombers could move all essentials at once, plus non-essentials of four squadrons by HQ pool, i.e. four squadrons could be completely mobile but the remaining six would have to await the return of the MT to move their non-essentials.

Air Stores Parks. Could move essentials for two weeks' consumption with own MT plus vehicles in HQ pool.

The degree of mobility to be achieved by this scheme was, in fact, considerably less than that recommended by Air Marshal Barratt at the conference on 5 February, which he thought had been approved by the investigating committee. Even this degree of mobility, however, was not attained. On 17 April, Air Marshal Barratt wrote to the Air Ministry complaining that the reorganisation in the AASF was held up because the new establishments for Headquarters MT Companies had not yet been received. He listed the following deficiencies in vehicles:

Vehicle Type	Deficient on existing establishments	Reserve Pool not yet established	Total Deficiencies
Staff cars	23	30	53
Tenders, 3-ton	116	200	316
Tenders, 30-cwt.	36	20	56
Vans, 15-cwt	69	40	109
Vans, 10/15-cwt.	66	40	106
Trailers, petrol (450 gallons)	28	25	53
Trailers, power. 7 kW	31	15	46
Trailers, W/T Receiving	22	10	32

Thus the deficiencies on 17 April in these classes, of which the large tenders and vans were the most serious, totalled some 771 vehicles. In a letter to the Air Member for Supply and Organisation two or three days later, Air Marshal Barratt emphasised the gravity of the position in these words

"If operations break out in the near future my ability either to move squadrons or to keep them properly supplied gives me considerable concern. If any of the MT which I do possess is damaged by air action the position is going to be even worse."

The fact that the BAFF figures were not overstated is confirmed by the Air Ministry data passed from WO3 to E8 during April. The figures do not correspond exactly, but in the above classes they totalled 708 vehicles while other classes not mentioned by BAFF Headquarters totalled a further 300 or so vehicles, making a total deficiency of about 1,000 vehicles in all.

On 7 May, Air Marshal Barratt asked the Air Ministry to state what steps were being taken to make up the deficiency, and on 11 May an official answer from the Directorate of Organisation vouchsafed an explanation of the delay which was caused, it said, by failure on the part of contractors to deliver 3-ton tenders in accordance with contract; the fact that the lighter type of van was a new development for the continental units, and it had only just become possible to obtain supplies to meet the new commitments; and finally, the fact that 'very urgent' needs (presumably the Scandinavian ventures) had absorbed vehicles which would otherwise have been available for France, together with the prior attention of the maintenance units responsible for preparing transport and equipment. It was announced, however, that the establishment of the MT Companies for the AASF Headquarters had now been issued, and that many vehicles had recently been or were about to be shipped. This, however, was the day after the German assault had opened. On 15 May it was calculated at BAFF Headquarters that the forces in France were still nearly 600 vehicles short in the main classes, though approximately 200 of these were in transit. The following day, both AASF and Air Component were to need all the transport they could lay their hands on.

It thus came about that when the moment of crisis arrived the British Air Forces in France were not only established to an official basis which was but semi-mobile, but were actually 600 vehicles short of this semi-mobility. It had been possible to carry out the reorganisation into Wing and Group MT Companies in the Air Component but the delay in issuing establishments for the AASF was such that the Headquarters MT pools projected in February were still not achieved by May. Ultimately it was necessary for the AASF to secure mobility by borrowing transport from the French and by reducing the number of its operational bomber squadrons from ten to six.

Maintenance Difficulties during the Final Stages of the Campaign in France and the Low Countries

Details of the operations carried out by the Royal Air Force in France and the Low Countries are not included in this article as these have been covered adequately elsewhere. For the purpose of the history of the RAF maintenance arrangements, the campaign may be separated into three phases

The maintenance difficulties experienced and the attempts made to produce an adequate organisation during the first two phases have been described in the foregoing paragraphs. During the final phase most of the difficulties resulted from the fact that when the intensive operational period commenced the reorganised maintenance organisation was still far from complete.

A high degree of serviceability of aircraft was maintained by squadron personnel throughout the campaign, and it is of interest to note that during the period of least action the unserviceability figures were far higher than during periods of intense operations, the reason for this being that during the quiet phases, advantage was taken to carry out minor replacements and modifications on aircraft which resulted in their being shown in returns as 'unserviceable'. During intensive operations squadron personnel were fully employed in routine maintenance and minor repairs and serviceability was largely maintained by calling on the Repair and Salvage Units for repair in situ. Squadron personnel could have undertaken more repair work (thereby enabling the Repair and Salvage Units to devote more effort to salvage) if it had not been necessary to employ technical personnel on non-skilled work such as ground defence, bomb carrying, etc.

The serviceability of mechanical transport was very adversely affected through all phases by the non-availability of spare parts. It had been intended to form a MT repair unit in the forward area but circumstances did not permit this to be introduced.

As regards the Repair and Salvage Units, it was demonstrated during the intensive period that even if their scale of personnel and equipment had been up to the establishment intended by the Air Ministry, it would have been inadequate to keep pace with requirements. The units were made fully mobile but it was not possible for them to undertake complete salvage operations and the RSU commanders were from time to time given priority of effort to meet the changing circumstances. Generally priority was as follows: -

In the case of (b) considerable latitude was allowed, and, provided that in the opinion of the engineer officer the aircraft would stand up to level flight to the United Kingdom, the aircraft was certified accordingly.

During the withdrawal the Repair and Salvage Units of the AASF did excellent work, particularly in the salving of valuable equipment of all kinds, including equipment which was so urgently required in the United Kingdom.

The units were, however, considerably handicapped by the fact that many of their vehicles had not been designed to undertake the salving and transportation of RAF equipment. In particular, although the establishment, of a RSU included one 3/5-ton crane for each mobile salvage section, these cranes had not been supplied.

The holdings of the Air Stores Parks were cut down immediately the German offensive opened in order to make the parks as mobile as possible. The work of the ASPs, however, fell off considerably, mainly due to the fact that squadrons and RSUs could not carry out repairs. During the retirement the majority of the parks, whilst on the move, commenced to function 24 hours after the arrival at a new destination, with the exception that they were not able to supply rations and petrol which were supplied from the base and consigned to selected railheads. Owing to the large stocks and insufficient transport, quantities of equipment and supplies were left behind in the forward area when the retirement first commenced, but, as the result of the efforts made subsequently, the parks completely cleared the equipment from this area with the exception of petrol and oils. The 100 octane petrol was salved but the remainder, with the oil, had to be handed over to the French authorities. The salved equipment was loaded onto trains and despatched to the base.

No 21 Aircraft Depot, as previously explained, had not got into its stride when the German offensive opened. Between 10 May and the second week in June, however, it managed to complete the repair of eight Hurricanes. The production work of the depot really came to an end in the first week of June, and the process of cutting down commenced. In this connection it will be remembered that the equipment holding section of the depot had, at the outset of the battle, only just been completed and fully stocked. On 24 May, in view of the success of the German offensive and the evacuation of the Air Component, a reduction of stocks was ordered. Forthwith 800 tons of equipment were shipped home. On 12 June arrangements were made for a further drastic reduction and from that date onwards the process became continuous. The result finally achieved was: -

Material which had to be abandoned consisted mainly of the equipment which had to be retained on wheels with the squadrons and Air Stores Parks while operations continued, and the vehicles which were required to keep the force mobile under the same conditions. Much of the RAF Component equipment was lost by German interception and there was no time or capacity to ship a great deal of the equipment of the AASF which actually reached the western ports at the end of the campaign. After our air forces had returned to the United Kingdom it was estimated by the Air Officer Commanding Maintenance Command that we had lost in France (exclusive of aircraft and equipment in squadrons and smaller units in the forward area) the equivalent of four complete Air Stores Parks, or items to the value of about £1,000,000. Fortunately, as described, evacuation priority was given to articles in short supply in England and the adverse effect on the Service was thus less severe than it might easily have been. The loss in aircraft from all causes amounted to nearly a thousand in the period 10 May to 20 June.