In late August nineteen fourteen, during the Battle of Mons, British generals still thought in terms of horse mounted scouts and field telephones. The German advance through Belgium and into northern France looked, from ground level, like a series of separate blows. British intelligence officers believed the Germans were moving south east, away from the British position. A pair of Royal Flying Corps crews went up to check.What they saw contradicted the neat arrows on the staff maps. German columns were swinging to the south west in a huge wheel movement that threatened to turn the British flank and cut them off. The pilots landed and argued their case. Senior officers were skeptical. They had never trusted information that came from the sky. Nevertheless, the reports kept coming. Different crews, different days, same story.Reluctantly, the British commander in chief accepted that the German movement was real. He ordered a retreat before his small army could be surrounded. Thousands of men who might have been trapped and destroyed instead survived to fight later battles. That decision depended on what two seat airplanes had seen from a few thousand feet up.From that moment, the importance of air reconnaissance lodged itself in the minds of serious soldiers. The old tools of scouting, rider and spy and balloon, had started to feel slow and local. The new tool looked across an entire sector in an hour. It carried information across mud that nothing with wheels could cross once winter rains began.Generals adjusted quickly. Airmen had to adjust faster.As trench lines hardened from the North Sea to the Swiss frontier, both sides grew hungry for ever more detailed information. Where were the enemy guns. How many. Which units held which sectors. Where were supply dumps, reserve positions, new railheads. The answers to these questions decided where offensives would be launched, where artillery would concentrate, where reserves would wait to exploit a breakthrough.Aircrews responded by turning reconnaissance into a craft. Observers learned to sketch trench systems at speed, noting the zigzag lines, strongpoints, dugouts and wire obstacles. They counted trains in rail yards. They estimated the density of troops from the number of campfires at night.Photography changed everything yet again.Before the war, aerial photography had been a curiosity. A few experimenters strapped cameras to balloons or crude aircraft, but nobody had built a system around it. By late nineteen fourteen, both sides were doing exactly that. Big, boxy cameras with glass plates were bolted to the sides of aircraft. Observers leaned out over the void to change plates in the slipstream, fingers numb in the cold, while the pilot tried to fly straight and level along a planned line.Each flight produced a strip of overlapping photographs. On the ground, specialists turned those plates into maps. They used stereoscopes to view images in three dimensions, revealing the height of trenches, the depth of craters, the exact location of artillery pits hidden by camouflage from ground eyes. Within months, the Western Front became the most photographed strip of land on earth.This did more than satisfy curiosity. It changed how artillery worked.In nineteen fourteen, gunners still largely relied on what they could see from their own positions or from forward observers with field telephones. That meant most firing was indirect guesswork. Shells fell short or long. Corrections were slow. Ammunition was wasted.With aircraft spotting for them, artillery units could do something new. A two seat airplane would take off, circle above the target area, and send down messages by radio or signal flares. Early radios were heavy, weak and unreliable, but they were enough. The observer would watch the fall of shot, then tap out a code on a crude transmitter, telling the battery to add so many yards, drop so many left. With each correction, the shells walked closer to the enemy trench or gun position.Soon, a pattern emerged. Aerial photographs identified targets. Artillery used air spotting to hit them with increasing precision. The enemy responded by building deeper dugouts, more elaborate camouflage and decoy positions. The sky had joined the age old duel between gun and shield.Then came the question that would turn reconnaissance into combat. If enemy aircraft were doing this for their side, how do we stop them.At first, the answers were almost comical. Pilots waved pistols at each other as they crossed paths. Observers hurled bricks. There is at least one account of a pilot attempting to ram an enemy by swinging his aircraft’s wingtip into the other machine, which ended as badly as you would guess.These scenes sound absurd, but they reveal something important. The concept of fighting in the sky was so new that nobody had considered what it would mean. There were no gun mounts designed for aircraft, no doctrine, no training. Yet the demand for control of the air was already there. Every time a reconnaissance machine returned safely after photographing your lines, it carried away the blueprint of your position.
