AOP Artillery Tactics

For anyone interested on WW1-era AOP operations, I can highly recommend “Sagittarius Rising”, Cecil Lewis’ autobiography of his time in the RFC. His first frontline posting was to an Army Co-op squadron flying two-seater Morane Type-L parasol monoplanes, and his vivid accounts of the dangers these guys faced makes your hair stand on end.
Firstly, the Type L had some pitch stability problems, and if you let go of the stick the aircraft could bunt so violently that the wing could part company. Keeping a hand on the controls at all costs was the order of the day!
Secondly, they were often operating well within range of the German flak (“Archie”), and even small arms.
Thirdly, they often operated alone, with no escort or top cover of any sort, leaving them open to attack from German scouts.
The fourth hazard is perhaps the most hair raising. This was the artillery shells themselves, both German and Allied. The standard response to an artillery barrage was to return fire with a barrage of your own. AOP crews often had shells pass them by in both directions, Lewis even recounts how you could see the shells rotating as they ‘drilled’ thier way through the atmosphere. Shells would sometimes collide and detonate in mid air, often too close for comfort for the AOP guys, and ofcourse there was every chance that your machine could be struck by a passing shell. This is in fact how Lewis’ usual Observer lost his life whilst flying with another pilot, his aircraft being hit by a British shell.
It’s also worth mentioning that the shells caused severe disturbance and turbulence, so it was extremely bumpy and uncomfortable work aside from the dangers. Bear in mind that the machines were already a tad unstable and that the wings didn’t need much encouragement to part company and you can begin to understand how nerve wracking the whole experience was.
Sagittarius Rising is a great read in general, if you haven’t read it you’re missing out on a brilliantly written aviation autobiography. Mine takes pride of place up on the shelf alongside Wing Leader etc as one of the greats.

I was thinking more of when the aircraft were able to directly speak to the arty on the ground in order to direct fire. Inter-war or earlier?

The RFC two-seaters in the late Great War period were fitted with a W/T transmitter, able to send morse to the artillery battery command. In return, artillery used ground sheet type signals to communicate back. Believe it or not it’s all covered (in detail, essentially accurately) in ‘Biggles Learns to Fly‘ among other Biggles books! See the chapter: ‘EYES OF THE GUNS’.

I believe that pre-arranged signals prior to the use of W/T were used, as well as the message bags. Also the RAAF Museum has a Spark transmitter on show from the period.

For more, I suggest you ask on The Aerodrome.

HTH

Whilst this does not help your question, if you are interested in this sort of period you should look up JFC Fullers Plan-1919. It would have heavily used aircraft and is realy the first true ‘Blitzkrieg plan’.

I was thinking more of when the aircraft were able to directly speak to the arty on the ground in order to direct fire. Inter-war or earlier?

Message bags with streamers were still used in WW2 as well as radio – 656 Squadron who operated Austers in the far east in WW2 lost a fair few message bags with streamers to Commonwealth African troops.

When they were dropped near positions occupied by African troops and went back to retrieve them, the troops were reluctant to give them back because the bags with the streamers dangling down were placed at the entrances to tents as they were believed to ward off evil spirits!

Message bags with streamers.

If one counts balloons as aircraft, I believe they were used for artillary spotting in the Napoleonic Wars.