Editing First day on the Somme (section)

===Air operations===
British Photographic reconnaissance began in October 1915 and in March 1916 intensive British preparations commenced. The IV Brigade of the RFC was formed on 1 April 1916, with six squadrons of aeroplanes and a Kite Balloon squadron; the IV Brigade squadrons were the first to be increased from twelve to eighteen aircraft. On 25 April photographs were taken which revealed the German construction of a third position from Flers northwards to Le Sars, Pys, Irles, Achiet-le-Petit and Ablainzevelle. In mid-May and late June, the German defences opposite the Fourth Army were photographed again.{{sfn|Jones|2002|pp=195–197}} {{lang|de|Die Fliegertruppen des Deutschen Kaiserreiches}} (Imperial German Flying Service) had six reconnaissance flights ({{lang|de|Feldflieger-Abteilungen}}) with {{nowrap|42 aircraft}}, four artillery flights ({{lang|de|Artillerieflieger-Abteilungen}}) with {{nowrap|17 aeroplanes}}, a bomber-fighter squadron ({{lang|de|Kampfgeschwader I}}) with {{nowrap|43 aircraft}} a bomber-fighter flight ({{lang|de|Kampfstaffel 32}}) with {{nowrap|8 aeroplanes}} and a single-seater fighter detachment ({{lang|de|Kampfeinsitzer-Kommando}}) with {{nowrap|19 aircraft,}} a strength of {{nowrap|129 aeroplanes.}}{{sfn|Jones|2002|p=201}}

The IV Brigade corps aircraft were to be protected with line patrols, comprising pairs of aircraft from the army squadrons and offensive sweeps by formations of [[Airco DH.2|DH 2]] fighters. The concentration of aircraft for the offensive was completed by the arrival on 19 June of the Ninth (headquarters) Wing with three squadrons and one flight, which brought the number of aircraft on the Fourth Army front to {{nowrap|167, plus}} eighteen at Gommecourt.{{sfn|Jones|2002|p=199}}{{efn|The Ninth Wing was under the command of RFC headquarters and operated as a mobile reserve, conducting strategic reconnaissance, offensive operations against {{lang|de|Die Fliegertruppen}} and long-range bombing.{{sfn|Jones|2002|p=199}}}} The bombing offensive by the RFC was intended to cut railway links behind the Somme front, south of the Valenciennes–Arras railway and west of the lines around Douai, Busigny and Tergnier. Trains were to be attacked in cuttings, railway bridges were to be bombed and the stations at Cambrai, Busigny, St Quentin and Tergnier were to be raided along with the German ammunition depots at Mons, Namur; the station at Lille was also to be attacked.{{sfn|Jones|2002|pp=198–199}} British aircraft and kite balloons were to be used to observe the intermittent bombardment, which began in mid-June and the preliminary bombardment, which commenced on 24 June. Low cloud and rain obstructed air observation of the bombardment, which soon fell behind schedule. On 25 June, aircraft of the four British Armies on the Western Front attacked the German kite balloons opposite; fifteen were attacked, four were shot down by rockets and one bombed, three of the balloons being in the Fourth Army area. Next day three more balloons were shot down opposite the Fourth Army and during German artillery reply to the Anglo-French bombardment, {{nowrap|102 German}} artillery positions were plotted and a Fokker was shot down near Courcelette.{{sfn|Jones|2002|pp=206–209}}

Accurate observation was not possible at dawn on 1 July due to patches of mist but by {{nowrap|6:30 a.m.}} the general effect of the Anglo-French bombardment could be seen. Observers in contact-patrol aircraft could see lines of British infantry crawling into no man's land, ready to attack the German front trench at {{nowrap|7:30 a.m.}} Each corps and division had a wireless receiving-station for messages from airborne artillery-observers and ground observers were stationed at various points, to receive messages and maps dropped from aircraft.{{sfn|Jones|2002|p=209}} As contact observers reported the progress of the infantry attack, artillery-observers sent many messages to the British artillery and reported the effect of counter-battery fire on German guns. Balloon observers used their telephones to report changes in the German counter-barrage and to direct British artillery on fleeting targets, reporting during the night by [[flash spotting]]. Air reconnaissance during the day found little movement on the roads and railways behind the German front; the railways at Bapaume were bombed from {{nowrap|5:00 a.m.}} Flights to Cambrai, Busigny and Etreux later in the day saw no unusual movement, although German aircraft attacked the observation aircraft all the way to the targets and back, two Rolands being shot down by the escorts. Bombing began the evening before with a raid on the station at St Saveur by six [[Royal Aircraft Factory R.E.7|R.E. 7s]] of 21 Squadron, whose pilots claimed hits on sheds and a second raid around {{nowrap|6:00 a.m.}} on 1 July hit the station and railway lines; both attacks were escorted and two [[Fokker Eindecker fighters|Fokkers]] were shot down on the second raid.{{sfn|Jones|2002|pp=209–215}}

Railway bombing was conducted by {{nowrap|28 aircraft,}} each with two {{cvt|112|lb}} bombs, at intervals after midday; Cambrai station was hit with seven bombs, for the loss of one aircraft. In the early evening an ammunition train was hit on the line between Aubigny-au-Bac and Cambrai and set on fire, the cargo burning and exploding for several hours. Raids on St Quentin and Busigny were reported to be failures by the crews and three aircraft were lost.{{sfn|Jones|2002|pp=215–216}}{{efn|German prisoners captured by the French army later in July, reported that they were at the station during the bombing, which hit an ammunition shed near {{nowrap|200 ammunition}} wagons. Sixty wagons caught fire, exploded and destroyed the troop train and two battalions' worth of equipment piled on the platform, killing or wounding {{nowrap|180 troops.}} Reserve Infantry Regiment 71 had to be sent back to Etreillers and then Ham to re-equip.{{sfn|Jones|2002|pp=216–217}}}} All corps aircraft carried {{cvt|20|lb}} bombs to attack billets, transport, trenches and artillery-batteries. Offensive sweeps were flown by 27 and 60 squadrons from {{nowrap|11:30 a.m. to 7:00 p.m.}} but found few German aircraft and only an [[LVG C.II|LVG]] was forced down. Two sets of line patrols were flown, one by 24 Squadron DH.2s from Péronne to Pys and Gommecourt from {{nowrap|6:45 a.m. to}} nightfall, which met six German aircraft during the day and forced two down. The second set of patrols by pairs of [[Royal Aircraft Factory F.E.2|F.E.2bs]] were made by 22 Squadron between {{nowrap|4:12 a.m.}} and dusk, from Longueval to Cléry and Douchy to Miraumont. for a loss of two aircraft and one damaged but prevented attacks on the corps aircraft.{{sfn|Jones|2002|pp=215–218}}

XIII Corps was watched by most of 9 Squadron, which saw the 30th Division troops take the line Dublin Trench–Glatz Redoubt by {{nowrap|8:30 a.m.}} and the 18th (Eastern) Division take Pommiers Trench and Pommiers Redoubt. At {{nowrap|10:00 a.m.}} an observer saw a line of flashes on the ground from mirrors carried by 30th Division soldiers on their packs as the British troops moved along Train Alley towards Montauban. A German artillery battery began to fire from Bernafay Wood and the pilot machine-gunned the crews from {{cvt|700|ft}}, putting the battery out of action. On return towards the British lines, the crew saw Montauban being occupied and 18th (Eastern) Division troops advancing up the ridge to the west of the village ,the pilot flew low along the ridge and gave the troops a wave. By {{nowrap|11:15 a.m.}} mirrors were seen flashing along the north edge of Montauban.{{sfn|Jones|2002|pp=213–214}}

The XV Corps attack on either side of Fricourt was observed by parts of 3 and 9 squadrons, which were able to report by evening that the 21st Division and the 34th Division to the north had advanced deeply into the German defensive positions above Fricourt. The 7th Division had advanced beyond Mametz, forming a defensive flank on the left and linking on the right with XIII Corps. Troops from III Corps and XV Corps lit red flares, which were quickly reported by observers in contact-patrol aircraft. A balloon observer from 3 Kite Balloon Section was able to get the artillery to re-bombard {{lang|de|Danzig}} Alley, after British troops were forced out by a German counter-attack, a second British attack in the afternoon took the trench easily. Most of 3 Squadron watched over the disastrous III Corps attack at La Boisselle and Ovillers and saw some 34th Division troops reach Peake Wood north of Fricourt.{{sfn|Jones|2002|pp=212–213}}

The attacks by X Corps and VIII Corps, from Thiepval to Serre were observed by crews from 4 and 15 squadrons. Ground observers could see much of the battle and communications were better than on other parts of the front. Some of the deeper British infantry advances could only be seen from the air, particularly those at {{lang|de|Schwaben}} Redoubt and Pendant Copse. 4 Squadron reported the hurried withdrawal of German artillery between Courcelette and Grandcourt during the afternoon and spotted the massing of German troops at {{nowrap|4:30 p.m.}} A special flight was sent to Thiepval and the pilot flew by at {{cvt|600|ft}} to examine the ground and report that the British attacks had failed. With 15 Squadron observing the disaster occurring to VIII Corps around Beaumont Hamel, the defeat of the British attacks and the repulse of the troops from the few areas where break-ins had occurred were reported by the aircraft observers.{{sfn|Jones|2002|pp=211–212}}

The VII Corps attack was observed by 8 Squadron, which had photographed during clear weather the day before. The attack of the 46th (North Midland) and 56th (1/1st London) divisions, had a standing patrol of one aircraft each from {{nowrap|6:45 a.m. to 3:25 p.m.}} and then one aircraft for both divisions. No red infantry flares were seen and aircraft flew through the barrage to make visual identifications at low level; by the end of the day German ground fire had made three aircraft unserviceable. One aeroplane flew into a balloon cable near St Amand, damaging the aircraft; the crew escaping unhurt. Reports from the observation crews related the fate of the leading troops of the 46th (North Midland) Division, who were cut off after over-running the German first line by German troops emerging from underground shelters. Following waves intended to mop-up the German front line were seen pinned down in no man's land by artillery and machine-gun barrages. On the 56th (1/1st London) Division front, observers watched the leading British troops capture the first, second and third lines before being cut off by another German barrage in no man's land. German infantry were seen to mass and then counter-attack, regaining the third line by midday, the second line by afternoon and the first line late in the evening.{{sfn|Jones|2002|pp=210–211}}