William Slade Vincent

4.1
Short Description of Artillery Reconnaissance [182]

Reconnaissance missions were dangerous. They were usually carried out by a crew of two. The pilot was required to fly straight and level to allow the observer to take a series of overlapping photographs. There was no better target for anti-aircraft guns, no easier prey for stalking fighters.

Long range reconnaissance meant flying well behind the front lines. Navigation on such flights was often a problem, and should the plane develop any mechanical trouble (as they often did) a friendly field to put down in was a long distance away. The German reconnaissance pilots had an advantage over their French and British counterparts in this respect, as the predominant winds blew from the west.

It was a complex business. The wireless equipment was too bulky and heavy for planes to carry both a transmitter and a receiver, so the aircraft flew with a transmitter only.

A plane would service a particular artillery battery, and before take off the battery’s target was confirmed. Once in the air the observer had to identify his battery and the target battery. He would then transmit a message ordering it to fire. He could usually differentiate shells that belonged to his battery by measuring the time from when they had fired till the explosion in the vicinity of the target.

From 1915 onwards the corrections, transmitted in Morse, were in the “clock code”: a letter was used to indicate the distance from the target (the letters Y, Z, A, B, C, D, E and F representing distances of 10, 25, 50, 100, 200, 300, 400 and 500 yards respectively) and a number in the range 1-12 representing the direction from the target (with 12 indicating due north of the target, and 6 representing due south of the target)

The R.F.C. pioneered successful artillery spotting at the Battle of the Aisne. A feature of this battle, which was quite typical of the entire Western Front, was that the Germans occupied higher ground. After the first two days the German gun positions were never visible to the British, being hidden behind the Chemin des Dames ridge. The daily reconnaissance and observation flights were an absolute necessity for the British gun batteries.

As in reconnaissance flights, artillery observation required the planes to fly steady, predictable routes. In addition to anti-aircraft fire and enemy fighters, observation aircraft suffered a third danger, and this was from the artillery shells themselves. They typically flew at an altitude similar to the apex of the artillery shell's flight, and they flew along a line between the guns and their targets. It was not unusual for the pilot or observer to actually see the shell as it stopped at the top of its climb before plummeting downward. It was not unknown for the planes to be hit by those shells.

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[182] firstworldwar.com – Michael Duffy