At the outbreak of the First World War, four RFC squadrons (2, 3, 4 and 5 Squadron equipped with a wide range of aircraft types) flew to France to join the British Expeditionary Force (BEF). Assigned to the General Headquarters (GHQ), the RFC provided reconnaissance during the critical first few months of the war as the Germans sought to outmanoeuvre the British and French Armies. The fluid military situation meant that HQ RFC and its four squadrons moved repeatedly, closely following the GHQ as the fighting edged north towards the Channel ports. Eventually, on the evening of Monday, 8 October 1914, HQ RFC arrived at St Omer and took up residence in a small chateau. The squadrons arrived over the next few days, together with the recently formed HQ Wireless Telegraphy Unit. These aircraft were joined by 6 Squadron who arrived from England with a mixture of BE2s, Bleriots and BE8s and together, they comprised the RFC’s frontline strength until spring 1915.

The BE2 was typical of the early aircraft operated from St Omer 1914-1918

HQ RFC was modest, initially just totalling eight staff officers under the command of Brigadier-General Sir David Henderson, GOC RFC. Even so, the accommodation was extremely cramped, with rooms doubling as offices and bedrooms. Trenchard’s aide, Maurice Baring, wrote a diary which provides a vivid picture of this initial period and an affectionate account of the personalities involved. ‘We arrived at St Omer at 8.30 and took up our residence in a small chateau on the hill between the town and the aerodrome. We didn’t expect to stay there long, so no real steps were taken to make ourselves comfortable at the start. The chateau was a modern stucco building, red and white. Downstairs were two drawing rooms, one bedroom, and a small sitting room. The small sitting room was Colonel Sykes’ office. One of the drawing rooms was made into an anteroom, the other into an office. The bedroom downstairs was Brooke-Popham’s. Upstairs, General Henderson had one big bedroom and a small office. Salmond, Barrington-Kennett and I shared a second, Murat had a third, and the fourth was to be occupied by other staff members”. As it transpired, the Headquarters remained at St Omer until 1916 and returned in 1917, occupying the same small chateau throughout – leased from its owner at a rental of 20 francs per day.

Maurice Baring in 1934

St-Omer rapidly became the RFC’s airhead in France. It was the destination for most squadrons deploying to the Western Front. This, together with the ferrying of replacement and time-expired aircraft and depot test flying, made for a very active airfield. Over the course of the war, thousands of aircraft were ferried between England and France – 3,226 in 1917 and 6,217 in 1918. Given the vagaries of the weather and the rudimentary navigation of the time, the journey was never without its hazards. The deployment of 29 Squadron from Gosport to St Omer in March 1916 resulted in the loss of 14 DH2s en route and was probably the most spectacular example of the difficulties that could arise.

When squadrons deployed, they usually flew their aircraft south-easterly, heading across the Channel, aiming to reach the French coast between Cap Blanc-Nez and Calais and then following the canals south to St Omer. The direct route lay between Dover / Folkestone and Cap Gris-Nez, some 21 miles. Groundcrew, including observers and transport, would travel by sea to Le Havre, Rouen or Boulogne, normally only rejoining their pilots and aircraft at their operational airfield. Individual pilots joining the RFC in France reported to the Pilots’ Pool at St Omer pending allocation to a squadron. The first step for all newly arrived aircrew was to obtain a billeting allocation from HQ RFC – generally in St Omer itself, as the messes around the airfield were invariably full. For many RFC personnel, this was their first time overseas, and St Omer symbolised everything new or different, whether it was the cooking, the size of the bed covers or the washing arrangements!

The sudden influx of military personnel and the increasing demand for temporary and permanent accommodation caused severe difficulties in the town and the surrounding villages. Maurice Baring records numerous incidents in the early part of the war relating to billeting problems. On one occasion, he mentions how he ended a sharp discussion with the Mayor of Longuenesse by holding up a German ten-pfenning piece he had found on the drawing-room floor – only to be chased after by a gendarme who insisted that the Mayor was not a German spy. Another more humorous incident involved the arrival of two old ladies at HQ RFC with a complaint about the behaviour of two officers billeted with them. They would only speak to General Trenchard since it was a matter of ‘grave indelicatesse’. Eventually, it transpired that the officers concerned had washed their socks in the kitchen sink.

As the RFC’s strength grew, so did the size of the headquarters. Although it remained sufficiently small to be able to deploy forward as the operational situation demanded, its role grew in importance as the number of squadrons increased, notably between October 1915 and July 1916, when the frontline strength grew from just over 100 to more than 400 aircraft. With the decentralisation of the RFC into brigades and wings on 30 January 1916, it became necessary to re-organise the headquarters on a higher basis. Until then, responsibility for technical issues had been a subsidiary duty of Lieutenant-Colonel H.R.M. Brooke-Popham, GSO1. The expansion in the front line and increase in operational tempo generated a host of engineering and administrative issues that necessitated a new establishment – organised on the basis of a corps staff – that provided for a Deputy Adjutant and Quarter Master General. Robert Brooke-Popham[Also ‘Air Marshall Robert Brooke Popham was appointed to this new post, in the rank of brigadier-general, from 12 March 1916. An experienced staff officer, Lieutenant-Colonel P.W. Game, was found to take over the operational side of the HQ.

HQ RFC’s day-to-day activities encompassed responsibility for managing the units in the field and the higher strategic direction of the RFC in France, including liaison with GHQ and the French Aviation Service. This necessitated, in addition to technical specialists, intelligence, medical, photography, supply and transport staff, as well as dedicated liaison officers. As the intensity of the air war grew, so did the number of forms and the volume of paperwork to be handled, including the production – from the middle of 1915 – of a weekly communiqué describing RFC operations on the Western Front (familiarly known as Comic Cuts).

Sir David Henderson remained in command of the RFC until 19 August 1915, when he returned to the War Office. He was replaced by Colonel H.M. Trenchard, who was promoted to brigadier-general on 25 August 1915 and major-general on 24 March 1916. Hugh Trenchard remained GOC until December 1917, commanding the RFC through the great battles of the Somme and Third Ypres. Both offensives involved moving the headquarters temporarily from St Omer to bring it closer to the operational area.

First staff of the Central Flying School with Major Hugh Trenchard third from the right.

As a major garrison and centre of British military activity, St Omer attracted numerous visitors throughout the war. This included the Royal Family, who first visited HQ RFC and the airfield on 4 December 1914, when King George and the Prince of Wales arrived as part of a tour of the Western Front. Later visits included that by Queen Mary on 5 July 1917 when, in the company of GOC RFC, she reviewed aircraft at the Depôt and witnessed a flying display. A photographer was evidently on hand as a famous series of still photographs recorded the event for posterity.

Operations 1914-1916

A contemporary sketch of the landing ground at St. Omer indicates how crowded the airfield was in the autumn of 1914. The five RFC squadrons and their transport and tents were deployed along the road (D198E) near the town racecourse. The supply column and transportable sheds were placed at the eastern end of the landing ground adjacent to the main road between St Omer and Abbeville (D928), while the Aircraft Park was set up on the opposite side of the road. The HQ Wireless Telegraphy Unit (later 9 Squadron) occupied the sandpit at the junction of the two roads. These dispositions provided the basis for the much larger site that would develop over the next four years.

Up to this point, the work of the RFC squadrons had largely comprised strategic reconnaissance. However, the role of aircraft in directing artillery fire was becoming increasingly important. For the First Battle of Ypres, all five RFC squadrons were actively involved (2 Squadron arrived at St Omer shortly before the battle opened on 19 October 1914, while 6 Squadron arrived on 21 October 1914) in artillery co-operation and tactical as well as strategic reconnaissance. During the battle, although the bulk of the RFC remained at St Omer, detached flights from all the squadrons were deployed forward to work more closely with the individual BEF Corps. 6 Squadron achieved notable success on 1 November when a two-seat Fokker of FA41 was forced down near St Omer and recovered to the Air Park for examination.

Maurice Farmans used from St Omer 1915

By the time the German attack had been halted in November, it was evident that it would be better if the RFC’s squadrons were permanently located closer to the front line. This move to a more decentralised organisation was formalised on 29 November 1914 with the creation of two separate Wings: No 1 Wing (comprising No 2 and 3 Squadron) under Lieutenant-Colonel H.M. Trenchard with its headquarters at Merville; and No 2 Wing (comprising No 5 and 6 Squadron) under Lieutenant Colonel J. Burke with its headquarters at St Omer. The squadrons had already moved forward: 6 Squadron to Bailleul (where the bulk of 5 Squadron had been operating since 23 October), 3 Squadron to Gouncham on 24 November and 2 Squadron to Merville on 27 November. This left just 4 Squadron and the Headquarters Wireless Telegraphy Unit at St Omer together with detached flights of No 2 and 5 Squadron.

Charles J Burke

Although the airfield was now less crowded, the large size of the landing ground and the proximity to GHQ would ensure that it remained a focus for RFC activity for the remainder of the war. Unlike many airfields on the Western Front, St-Omer permitted a relatively long take-off run and unrestricted approaches for landing unless the wind was from the north or south. The site was also well served by the proximity to the town of St Omer with its workshops and billets, while it was only a short distance from the Channel ports from where men and materiel could be readily transported by road, rail or canal.

St Omer

The increasing importance of wireless telegraphy saw the formation of 9 Squadron from the HQ Wireless Telegraphy Unit on 8 December 1914. However, as is described in the accompanying article, the demand for wireless was such that flights from 9 Squadron were soon allocated to the individual Wings. In the event, 9 Squadron’s existence was destined to be brief – its success in developing wireless co-operation led to the decision to disband it in the field in February 1915. The wireless flights were absorbed by No 2, 5 and 6 Squadron and a new unit, 16 Squadron, was created from the aircraft and personnel displaced by the ex-9 Squadron wireless flights. 16 Squadron, together with 4 Squadron, was formed into a new (Third) Wing, based at St Omer, under the command of Lieutenant-Colonel H.R.M. Brooke-Popham, who led it until 26 May 1915 when he handed over to Lieutenant-Colonel J.F.A. Higgins, prior to succeeding Lieutenant-Colonel F.H. Sykes as GSO1 at HQ RFC.

Shortly after its formation, Headquarters Third Wing hosted a dinner party at the chateau they occupied in Longuenesse, inviting the owners who were living in the town. Unfortunately, the evening became a gastronomic if not a social disaster when the Mess Sergeant and the other staff, under the excitement of the event, consumed more alcohol than was good for them – although the guests of honour seemed unperturbed by the events.

The first months of 1915 were spent in a range of activities, including reconnaissance, bombing, photography, and artillery spotting. Although poor weather limited operations, 4 Squadron was as active as possible, attacking targets well behind German lines and losing both aircraft and pilots. This included their CO, Major G.H. Raleigh, who was killed in a crash at Dunkirk on 20 January 1915 when returning from a raid on Ostend.

Although formed on 10 February, 16 Squadron’s first operational sortie – an escorted reconnaissance of German lines – did not occur until 26 February once their working-up period had been completed. The squadron’s period at St Omer turned out to be brief, moving to La Gorgue on 6 March to join the First Wing. Their place at St Omer was taken by 1 Squadron, equipped with Avro 504s and BE8s, who arrived from England on 7 March 1915.

Spring 1915 saw the beginning of sustained air fighting as a series of offensives was mounted against the German frontline. The RFC was closely involved in supporting the attack against the village of Neuve Chapelle that opened on 10 March 1915. Although the bulk of the air co-operation fell to the First Wing, the St. Omer squadrons played an active role before the offensive ended on 12 March 1915. 1 and 4 Squadrons bombed railway junctions and bridges while 9 Squadron undertook artillery wireless co-operation. During a night bombing operation against Lille on 11 March, 4 Squadron lost all three BE2bs involved, Captain R.J.F. Barton crashed on take-off while Lieutenant A.StJ.M. Warrand and Captain G.W. Mapplebeck were shot down over the target. Warrand was killed, but Mapplebeck evaded capture and later escaped to the UK through Holland. 1 Squadron had more luck on 12 March when Captain E. Ludlow-Hewitt led four BE8s in an attack with 20lb bombs against a railway bridge northeast of Douai and a junction at Don, only losing one aircraft. Towards the end of the month, however, the squadron suffered another loss when Second Lieutenant J.C. Joubert de la Ferte and Lieutenant D.M.V. Veitch were forced to land in Holland, both being interned. [BE8]

Further squadrons arrived at St. Omer in the following weeks to reinforce the RFC. 7 Squadron (RE5s and Vickers Fighters) on 8 April 1915 and 8 Squadron (BE2cs) on 15 April 1915. [RAF RE5] Both units were incorporated into the Third Wing and employed on strategic reconnaissance work and special missions for GHQ – taking the places of 1 and 4 Squadrons who moved forward to the airfield at Bailleul. Shortly before 4 Squadron’s departure, they scored a notable success on 17 April 1915, when Captain R.M. Vaughan and Second Lieutenant J.F. Lascelles in BE2c 1669 forced down a German aircraft in French lines.

The new squadrons arrived in time to help repel the next German attack against Ypres, beginning on 22 April 1915. To interrupt the movement of German reserves, RE5s of 7 Squadron and BE2cs of 8 Squadron left St Omer on the afternoon of 26 April 1915 to bomb stations and trains in the Ypres salient. Similar attacks continued for four weeks until the German attacks ceased on 25 May.

Even before the Second Battle of Ypres concluded, a new Allied offensive had commenced on 9 May 1915 against Aubers Ridge and Festubert. Although the majority of the air support fell to the First Wing, 7 Squadron provided valuable intelligence throughout the battle. By now, the Third Wing comprised No 1, 4 and 7 Squadron – 8 Squadron had joined the Second Wing at Abeele on 1 May 1915 – although only 7 Squadron was resident at St Omer (together with the Third Wing Headquarters). The attack made little progress as the advance was impeded by a shortage of artillery ammunition and poor weather that limited the RFC’s contribution.

By June 1915, there was just one resident squadron at St Omer. Following a reorganisation of the Third Army, Headquarters Third Wing relocated to Beauquesne on 20 July 1915, and 7 Squadron remained behind as the GHQ squadron. 4 Squadron had originally undertaken this role until 7 Squadron replaced it in April 1915. Indeed, until 30 March 1916, when GHQ moved to Montreuil in anticipation of the Somme offensive, at least one RFC squadron was always based at St Omer for GHQ tasks, including defence against German air attack.

The obvious strategic importance of St. Omer meant that it was subject to increasing attacks by day and night as the war progressed. The first recorded incident was on 8 October 1914, when HQ RFC first arrived at St Omer. According to Maurice Baring, the Germans dropped a bomb on the school shortly to be occupied by GHQ – indicating to some at least the miraculous divination of the German Secret Service! After that, air raid warnings occurred regularly, although many were false alarms. Particularly heavy raids were experienced in 1917 and 1918, resulting in significant damage to the town and military installations and numerous civilian and military casualties.

July 1915 saw the arrival of No. 10 and 11 Squadron, but they were destined to spend only a few days at St Omer before they flew on to their destination airfields. A further three squadrons would deploy in this fashion during 1915. This rose the next year to 16 before falling back to 11 in 1917 and a further 11 in 1918. Therefore, although 43 squadrons deployed to St Omer during the war, they were mostly only there for weeks or even days.

7 Squadron remained at St. Omer until September 1915 and the opening of the Battle of Loos. The Western Front was relatively quiet during the intervening period, and the squadron engaged largely in strategic reconnaissance. However, they also faced increasing German opposition to these activities. On 3 July, an RE5 was lost after a reconnaissance of Ghent, and the crew interned in Holland, as was the crew of another RE5 on 21 July. Further combats were reported on 26 and 29 July, with yet another crew shot down and interned in Holland. On 31 July 1915, an enemy two-seater attacked Captain J.A. Liddell and Second Lieutenant R.H. Peck, flying RE5 2457 on a reconnaissance of Ostend. In the exchange of fire, Captain Liddell was badly injured, but rather than land in enemy territory, he managed to fly the aircraft back to a Belgian airfield despite great pain and loss of blood, John Liddell was awarded the Victoria Cross for his bravery but died from his wounds a month later on 31 August 1915.

7 Squadron’s tenure at St Omer ended on 11 September 1915 when it was replaced by 12 Squadron, under the command of Major C.L.N. Newall, who had recently arrived from England and equipped with a mixture of BE2cs, RE5s and RE7s. Although there was still only an operational squadron based at St. Omer, the airfield remained extremely busy as the work of the depôt continued to expand. However, little, if any, permanent building had occurred, and as one contemporary observer noted, the site was ‘a rather untidy jumble of canvas hangars and sheds around the airfield’.

Like its predecessor, 12 Squadron was employed mainly on long-range reconnaissance tasks. An excellent account of this period (including the workings of GHQ RFC) is provided by Lieutenant R.R. Money, who served as an observer throughout their time at St Omer. Shortly after the squadron’s arrival, it was heavily involved in the preparations for the Battle of Loos[Add date ‘1915’. Could also add casualty figure for the battle]. The opening artillery bombardment commenced on 21 September, including special bombing operations conducted by the Second and Third Wings and 12 Squadron. These attacks were directed at trains on the move, especially in cuttings, and commenced on 23 September – two days before the infantry attack. 12 Squadron undertook three attacks on the opening day and participated in further attacks over the next five days. During one of these raids on 26 September, the squadron experienced its first casualty when Captain F.B. Binney in BE2c 1744 was forced to land behind German lines after bombing a train from 500ft. Further organised bombing attacks took place on 30 September and on 13 October to stem German counter-attacks before the fighting ended in the middle of the month.

For the remainder of the year, the squadron continued to undertake defensive patrols and long-range reconnaissance, the latter against increasing opposition from German fighters. A Be2c was lost over Bruges on 19 December during a reconnaissance of Brussels, while an RE7 was shot down on a reconnaissance of Lille on 12 January 1916. Fortunately, no other aircraft were lost before the squadron left St Omer in February to join the newly formed 3rd Brigade.

12 Squadron would stay longer at St Omer than any other flying unit other than 4 Squadron. It was also significant for the events of 3 January 1916 when the bomb store on the aerodrome caught fire. The squadron CO, Major Cyril Newall, broke into the shed with his corporal driver to put out the fire – even though some of the incendiary bombs were already alight. They worked for 10 minutes alone, and for an hour afterwards, Newall, a dirty and blackened figure, took the lead in rolling red-hot bombs out of harm’s way. Both individuals were decorated for this action, Cyril Newall receiving the Albert Medal[Current value of the medal? ].

The significant expansion of the RFC in France also saw the arrival of the first dedicated single-seat fighter squadron, 24 Squadron, on 7 February under the command of Major Lanoe George Hawker. The very next day, the squadron undertook defensive patrols in the protection of GHQ, even though they were still gaining flying experience on type. Unfortunately, they almost immediately lost one of their DH2 fighters in a flying accident at St Omer, the pilot Lieutenant E.A.C. Archer being killed, before their 12 DH2s left for their operational airfield at Bertangles.

With the departure of 12 Squadron to Vert Galant on 28 February 1916, the GHQ role fell briefly to 25 Squadron and then 29 Squadron, both recently arrived from England. As mentioned, 29 Squadron’s arrival was less than trouble-free, and it would not be until 14 April that it could muster its full strength of 12 DH2s. The squadron’s first recorded air combat occurred on 2 April 1916 when Lieutenant G.S. Bush attacked a German two-seater over Ypres – but without effect. On 15 April, 29 Squadron moved to Abeele and, after that, until the return to St Omer of 4 Squadron on 16 April 1918, the airfield did not host any operational squadrons – although it continued to provide a temporary home for squadrons newly arrived from England.

These changes were presaged by HQ RFC’s departure for St Andre on 30 March 1916 in anticipation of the Somme offensive. The event was marked by the presentation of a silver cup to the chateau owners to commemorate the 18 months they had hosted the Headquarters Staff.

Over the following months, St Omer would become an increasingly active repair and supply depot. Although more than 30 squadrons would pass through the airfield over the next two years, most only stayed a few days or weeks en-route to their front-line airfields. For the immediate future, therefore, the airfield would be dominated by the activities of No. 1 Aircraft Depot.

The Aircraft Depot

When the RFC was formed in May 1912, with its constituent Military and Naval Wings, it was recognised that squadrons in the field would need dedicated support beyond that provided by the Royal Aircraft Factory at Farnborough. This task was assigned to the Line of Communications Workshop, later to become the Flying Depôt and, ultimately, the Aircraft Park. Under that title, it was deployed to France on the outbreak of war, reaching Boulogne on 18 August 1914.

When it arrived in France, the Aircraft Park comprised just 12 officers, 162 other ranks, four motorcycles and four aeroplanes in crates. The Official History records that on disembarkation, the port landing officer sent an urgent wire to GHQ, ‘An unnumbered unit without any aeroplanes which calls itself an Aircraft Park has arrived. What are we to do with it?’ Despite the unpromising start, the Aircraft Park soon proved invaluable in the constant struggle to keep the RFC’s handful of aircraft available to support the rapidly moving armies. During the confusion of the first months of the war, the Air Park found itself constantly on the move. However, after five changes in location, it arrived at St Omer by the end of October 1914, where it would remain for nearly four years.

As the war grew in scale and intensity, so did the logistic demands. The Aircraft Park came to resemble, in the words of its commander, ‘A gigantic factory and emporium’, repairing everything from aircraft to wireless equipment and vehicles. The range and quantity of spares to be handled created immense difficulties. The stores section was responsible for requisitions ranging from complete aircraft to horse rakes and lawnmowers for keeping aerodromes trim. By July 1915, the Aircraft Park had become too unwieldy to satisfy the demands placed upon it, a second park being established at Candas to cater for the southern squadrons. Both parks were supplied by rail from port depôts based at Boulogne and Rouen. Even with these changes, it was evident that unless St. Omer and Candas were relieved of some of their heavy repair work and the increasingly large range of stores they were now required to hold, there was no possibility that they could sustain a mobile role. In December 1915, it was decided to convert St. Omer and Candas into fixed supply and repair depots and to create three new air parks in the army rear areas to provide mobile support to the flying squadrons. St Omer was retitled No 1 Aircraft Depot (AD) and Candas No 2 AD.

At this stage, St Omer comprised some 1000 technical personnel (including MT workshops in the town itself on the Rue Therounne and a sub-site at Arques, some two miles away, engaged in kite balloon repair and the production of hydrogen) organised into a wide range of repair and stores sections holding three month’s stock of aeronautical and transport stores. The depot received, modified and issued direct to the front-line new aircraft, maintained an attrition reserve and overhauled and reconstructed aircraft, balloons and vehicles. In this regard, the importance of salvage cannot be exaggerated. Wastage rates at the beginning of the war were relatively low, about 10% per month, but by June 1916, they had reached 47.7% per month, rising to a staggering 64.6% during the Battle of the Somme. To keep 1800 aircraft in the field (the size of the RAF at the Armistice), it was calculated that 1500 new aircraft would have to be delivered to France each month.

The importance of St Omer and its sister depôt 2 AD at Candas in maintaining the operational effectiveness of the RFC during the Battles of the Somme and Third Ypres cannot be exaggerated. In the face of rapidly growing attrition, every aircraft that the depôts could repair or rebuild and every component or engine that could be salvaged was crucial. Thus, during September 1917, at the height of the Third Battle of Ypres, St Omer and Candas, working day and night, issued 930 aircraft, reconstructed 116 and erected 113. By October of that year, the volume of new aircraft deliveries (then averaging 400 a month) and the quantity of repair and salvage work had reached a level that necessitated the creation of a separate Aeroplane Supply Depôt (ASD) alongside the main depôt, responsible solely for aircraft receipt, issues and repairs.

Attached to the Depôt was the Pilots’ Pool that undertook ferry and flight test duties and provided refresher and conversion flying. It also served as a holding flight for recently arrived pilots awaiting posting to an operational squadron. Cecil Lewis, who was based at St Omer in March 1916, describes the airfield as buzzing with activity. Reporting directly to Lieutenant W.F.C. Kennedy-Cochran-Patrick, OC of the Pilot’s Pool, he flew various aircraft types and witnessed comparative trials with a captured Fokker.41 Charles Cochran-Patrick had been based at St Omer since December 1915. His duties were wide and included instructing and conducting experimental trials. However, his most notable achievement was probably the shooting down, on 26 April 1916, of an LVG two-seater FA5 over Hazebrouck while flying his personal Nieuport 16. This was the first and only aerial victory achieved during the war by 1 AD.

Up to this point, the depôt had consisted of only temporary sheds and several Bessonneau hangars. However, contracts were now raised through the RE Works Directorate for the construction of workshops and repair sheds, including a dope shop, carpenters’, fitters’ and sailmakers’ shops, and four small fuselage sheds. Further extensions were provided in 1917, including larger sheds, a Power House and 13 ‘B’ type hangars. The attached sketch[Need the sketch which is not online] shows the site’s layout in March 1918, shortly before being evacuated.

A significant works programme was also put in hand at Arques to cope with the increase in the demand for hydrogen as the number of RFC kite balloon sections deployed on the Western Front rapidly grew from 1916 onwards. Hydrogen supplies had originally been obtained through the French authorities, but increasing difficulties were encountered as consumption grew. It was decided to create a local generating capacity at Arques, adjacent to the canal, some four miles from 1 AD, to provide an assured supply.

Early in 1916, Colonel Robert Brooke-Popham had written to the War Office arguing for the provision of two Silicol Plants and compressors capable of producing 50,000 cubic ft of hydrogen per week. These plants were to be provided by the Admiralty together with the additional gas cylinders to increase the total number available on the Western Front to 8,000. Empty cylinders were delivered to Arques by lorry, and full cylinders returned directly to the kite balloon sections. At this stage, several large balloon sheds had been erected. Over the next two years, numerous additional buildings were constructed to provide for the hydrogen-producing plant and the handling of gas cylinders. In addition, fully hutted camps were provided for officers and other ranks, including WRAF.

Although only small quantities of oxygen were required by the RFC in the first years of the war (in general for welding), with the introduction of higher-performance aircraft from 1917 onwards, an increasing amount of compressed breathing oxygen was required – ultimately reaching 25000 cubic ft per day. The installation of an electrolytic plant at Arques addressed this need – as well as allowing a further increase in hydrogen production.

By March 1918, the St Omer depôts had grown into an immense enterprise. Over 4300 technical personnel (nearly 10% of the total strength of the RFC in France and Belgium) were directly employed in maintaining, modifying, repairing and salvaging aircraft and associated equipment. The scale of this operation and the haphazard development since the beginning of the war did not make for a pretty sight. Based in the Pilot’s Pool during 1917, Arthur Gould Lee described the depôt as an ugly, sprawling place with scores of Bessonneau canvas hangars and workshops with rows and rows of Nissen huts.

The German Spring led to a major relocation of the fixed repair and supply depôts. Even before the full extent of the German advance was known, thought had been given to placing the aircraft depôts closer to the Channel Ports. In late March 1918, 1AD was directed to find a suitable site adjacent to the St Omer to Calais railway and canal or the Calais to Boulogne railway. As an immediate step, a reserve stock of spares was created to keep the northern squadrons supplied if a move was deemed necessary (equivalent to some 250 lorry loads). As the military situation deteriorated, Robert Brooke-Popham decided to implement these plans. The advanced section of 1AD was ordered to Guines on 11 April 1918 – an existing site occupied by 4 ASD – while the stores section went to Desvres. Further moves out of St Omer occurred on 15 April, when 1 ASD and its repair section moved to Marquise and the MT Repair Shops were dispatched to join those of 2AD. The War Diary of the St Omer Area Commandant recorded that the evacuation of the heavy units had proceeded very satisfactorily, 1 ASD being cleared in three days. The evacuation of the St Omer site was completed on 10 May 1918 when the residual depôt elements moved to Guines – leaving only the Hydrogen Silicol plant and tent stores at Arques from the original depôt.

Even amid this turbulence, the supply system did not falter such that 208 Squadron, who had burnt their entire complement of Sopwith Camels when their airfield was overrun in heavy fog on 7 April 1918, was issued by the depôts with 20 new machines within 48 hours.

Operations 1918

With the move of 1AD and 1 ASD, St Omer once again became an operational airfield. This final phase was initiated by the arrival of 4 Squadron equipped with RE8s on 16 April 1918, followed by the SE5as of 29 Squadron on 22 April, the Camels of 210 Squadron on 27 April and the Dolphins of 23 Squadron on 29 April. The latter left within a fortnight, but there would always be at least two operational squadrons based at St Omer for the next five months.

St Omer 1918 RE8 engine being hand turned to prime it with fuel.

4 Squadron was destined to stay at St Omer for over five months, occupying the hangars at the western end of the airfield. Under the command of Major R.E. Saul, it formed part of the Second (Corps) Wing and was employed in direct support of XV Corps. As such, it played an active role in helping to stem the German Spring offensive and supporting the subsequent Allied advances. As a corps squadron, its RE8s undertook a wide range of co-operation tasks, including artillery observation, photography and contact patrols. A high price was paid for this effort. The day after their arrival at St Omer, an RE8 was caught by German fighters and forced to land as both crew members were wounded. A further five casualties were suffered before the end of the month, including three killed. Ground and friendly fire also exacted their toll on the squadron. For example, on 16 June 1918, Lieutenant P. Bertrand and Lieutenant C. Levick were killed when their RE8 suffered a direct hit from a British artillery shell. It is a mark of 4 Squadron’s dedication, and that of the corps squadrons as a whole, that they continued to perform their role in the face of continuing attrition. On 14 September, just two days before 4 Squadron left St Omer, they lost yet another RE8 to German fighters, the pilot Lieutenant T.O. Henderson being wounded and the observer Second Lieutenant F. Butterworth killed. Over the five months at St Omer, the squadron suffered at least 40 casualties, with more than ten aircraft shot down.

The other units that arrived at St Omer were all fighter squadrons. 29 Squadron was still working up, having recently replaced its Nieuports with SE5as. After a series of initial accidents, probably due to unfamiliarity with the new aircraft, the squadron’s combat record steadily grew. By the time they left St Omer for Vignacourt on 11 June 1918, some 19 enemy aircraft had been destroyed or driven down for the loss of four pilots. The squadron’s stay at Vignacourt was brief as they returned to St Omer on 22 July 1918. By now, they were enjoying considerable success, and on the first evening of their return, three two-seaters were destroyed. A further three victories were scored before 29 Squadron left St Omer for the last time on 1 August 1918, joining the 11th (Army) Wing at Hoog Huis.

SE5 and Bristol F2b being serviced. St Omer 1918

The Camels of 210 Squadron experienced mixed success during their month at St Omer. Two days after their arrival, they lost a pilot to AA fire while a further two aircraft were damaged on 6 and 8 May 1918, respectively. Although four enemy aircraft had been claimed destroyed by 15 May, the squadron suffered a serious loss when a pair of Camels collided in the air; both pilots were killed. By the time 210 Squadron left St Omer on 30 May 1918, eight more victories (including a hostile kite balloon) had been added for the loss of two further Camels (one pilot killed in action).

The departure of 210 Squadron saw the arrival of 54 Squadron, but only briefly, before being replaced by 85 Squadron, equipped with SE5as, under the command of Major ‘Billy’ Bishop. Elliot White Springs has recorded how impressed he was at the speed with which the squadron, having received its orders to move from Petit Synthe in the late morning of 11 June 1918, was packed and on the move within a few hours, the aircraft landing at St Omer later in the afternoon.

Notwithstanding the later controversy, it is clear that Bishop set an example of aggressive air fighting during his brief tenure at St Omer. Before his departure on 19 June for Home Establishment, he claimed 13 further aircraft were destroyed to bring his total score to 72. Five of these victories were scored on his last day in command of the squadron.

Bishop’s successor was Major ‘Mick’ Mannock, an experienced fighter pilot with over 50 aerial victories. Mannock did not arrive at St Omer until 5 July 1918, but it quickly became evident that his leadership style was very different to Bishop’s. He spent considerable time developing more effective combat tactics, building a strong team and, in particular, encouraging the younger and less experienced pilots. Even so, he steadily added to his own total before he was shot down by ground fire and killed on 26 July 1918 on an early morning sortie from St Omer in company with Lieutenant D.C. Inglis – but not before he had scored his 61st victory. The Germans found and buried his body, but the burial site was subsequently lost. He is now commemorated with more than 1,000 other airmen with unknown graves on the memorial at Arras.

The loss of Mick Mannock was a severe blow to the squadron, although he would be awarded a posthumous VC in 1919 for his ‘fearless courage, remarkable skill, devotion to duty and self-sacrifice’. Mannock was undoubtedly an inspirational leader who left the newly formed Royal Air Force, an example of professional airmanship and inspirational leadership that would serve it well in the coming years. Command of 85 Squadron passed to Major Cyril Crowe, another successful ace with 14 victories, who led the squadron until the war’s end.

A notable success during Mick Mannock’s period of command was the fight on 24 July 1918 with six Fokker DVIIs (believed to be Jasta 43). At least four enemy aircraft were reported shot down – German records indicate that three were forced to land and others were damaged. 85 Squadron was probably the most successful fighter squadron to operate from St Omer during the war. In addition to Bishop and Mannock, other high-scoring aces included Capt M.C. McGregor and A.C. Randall, as well as Lt A.S. Cunningham-Reid and J.W. Warner. During its stay at St Omer, the squadron claimed over 58 aerial victories (including one Kite Balloon) for the loss of nine pilots killed, injured or POW.

85 Squadron left St Omer for Bertangles on 13 August 1918, being replaced the next day by 41 Squadron, also equipped with SE5as, under the command of Major G.H. ‘Beery’ Bowman. The squadron’s first successes did not occur until 17 August when Capt F.R. McCall claimed an LVG two-seater out of control and Lt W. Shields destroyed a Pfalz scout. However, the day was one of mixed success as the squadron lost one of their most successful pilots, Lt W.G. Claxton, who was shot down and made a POW, and Lt T.M. Alexander, who was killed in combat. A further ten victories (largely Fokkers) were claimed during the remainder of the month for the loss of one pilot, 2Lt A.V.F. Trimble, killed in action. September saw a further six claims, including a balloon destroyed in flames by Capt F.O. Soden on 15 September.

The transfer of 41 Squadron to Droglandt on 20 September, two days after 4 Squadron had also left S Omer, represented the final chapter in the airfield’s close association with the British Air Services. With the German Army in retreat, the fighting was moving steadily out of the effective range of aircraft at St Omer. Although some personnel and units remained well into 1919, including a handful of aircraft, the departure of 41 Squadron’s SE5as effectively marked the end of St Omer as a major airfield and closed an intimate association with the British Air Services that had lasted for almost four years.


I’ve got a windy feeling round my heart
And it’s time that we went home!
I’ve got a great big longing to depart.
Somewhere back to Omer Drome
Huns are diving at my tail.
Wind up – Gee! – I’ve got a gale
Guns are jamming
Pilots are damning
Archies bursting all around us
And observers say
‘Ain’t it time that we came down?’
So won’t you splitass back
Along the track
To my dear old Omer Town?

Royal Flying Corps song, circa 1916, sung to the tune of ‘My Old Kentucky Home.’