Mist and cloud made air observation difficult on the morning of 16 August, until a wind began to blow later in the day but this shifted the smoke of battle over the German lines, obscuring German troop movements. Corps squadrons were expected to provide artillery co-operation, contact and counter-attack patrols but low cloud, mist and smoke during the morning resulted in most German counter-attack formations moving unnoticed. Flash spotting to find the positions of German artillery was much more successful than in previous attacks and many more flares were lit by the infantry when called for by the crews of contact aeroplanes. Army squadrons, Royal Naval Air Service (RNAS) and French aircraft flew over the lines and attacked German aerodromes, troops and transport as far as the weather allowed. V Brigade RFC tried to co-ordinate air operations over the battlefield with the infantry attack. Two Airco DH.5 aircraft per division were provided to engage any German strong points interfering with the infantry attack on the final objective. Two small formations of fighters were to fly low patrols on the far side of the final objective of the Fifth Army, from the beginning of the attack for six hours, to break up German attempts to counter-attack and to stop equivalent German contact-patrols.