??y the end of 1914 the Inspektion der Fliegertruppen developed a system to allow air-to-ground communication. The first viable apparatus was made by two firms, Hirth and Telefunken, and was successfully introduced in three FFAs in March 1915. Very soon all squadrons were equipped with two wireless sets ??on 1 April II MLA sent two aircraft to AFP4 in Ghent to be fitted with the new equipment.

The set developed by Telefunken weighed some 15 kg/ 33 lb and had three wavelengths: 150, 200 and 250 metres. It had a range of some 40 km/ 25 miles and was therefore powered by a windmill-driven generator and a 37m/ 40 yard bronze antenna which was suspended under the plane.
German wireless communication improved during the Second Battle of Ypres. After the ??lane had taken off, the observer unrolled the antenna and gave a signal to the airfield. If everything was all right, the ground crew fired a Very light, then the ??lane headed for the front, where the observer tried to establish contact with the artillery?? wireless station. Once they had good reception of the aircraft?? Morse code signals, they laid out two large white cloths side by side on the ground. The observer would then give the number of the target and the number of the battery which should fire. The cloths were then laid out in the form of a cross shape and on seeing this, the observer ordered the battery to fire. The ??lane would then head back towards the target and the observer would look for the impact of the shell and signal back the results.

Letter = Meaning
W ??zu weit (too far)
K ??zu kurz (too short)
ZM ??Zielmitte ! (goal !)
R- rechts (the shell had fallen to the right of the target)
L ??links (the shell had fallen to the left of the target)

Each message was repeated three times, for example: R, R, R

Messages might read as follows:
L 02 W 3 ??The shell fell 20 m too far to the left and 300 m too far.

This communication would continue until all targets were destroyed, and depending on available fuel, the aircraft would identify a new target or return home.??

Above Ypres: The German Air Force in Flanders 1914-18, Bernard Deneckere, P46.