January – 30 June From 30 January 1916, each British army in France had a Royal Flying Corps brigade with a corps wing containing squadrons responsible for close reconnaissance, photography and artillery observation on the front held by the army and an army wing for long-range reconnaissance and bombing, its squadrons using aircraft types with the highest performance. On the Somme front (Imperial German Flying Corps) had six reconnaissance flights () with , four artillery flights () with , a bomber-fighter squadron () with a bomber-fighter flight () with and a single-seat fighter detachment () with a strength of Some of the German air units had recently arrived from Russia and lacked experience of Western Front conditions, some aircraft were being replaced and many single-seat fighter pilots were newly trained. German air reconnaissance had uncovered British–French preparations for the Somme offensive and after a period of bad weather in mid-June, French preparations were also seen as far south as Chaulnes. British aircraft and kite balloons, were used to observe the intermittent bombardment, which began in 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, 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. During German artillery retaliation against the British–French bombardment, artillery positions were plotted and a Fokker was shot down near Courcelette. 1 July Accurate observation was not possible at dawn on 1 July, due to patches of mist but by the general effect of the British–French bombardment could be seen. Observers in contact aircraft watched lines of British infantry crawl into no man's land, ready to attack the German front trench at Each corps and division had a wireless receiving-station, to take messages from airborne artillery-observers and observers on the ground were stationed at various points, to receive messages and maps dropped from aircraft. 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 artillery. Balloon observers used their telephones, to report changes in the German counter-barrage and to direct British artillery on fleeting