Thanks to both.
I am surprised at the lack of data due to the importance of both events, in which at least with the Zep raid, the RNAS appears not to have been afraid of the camera before lifting off.
As for the other, once again, the importance propaganda wise created post event photo/film taking. I will stick my neck out based on what little I have dug up.
The four aircraft being discussed had the extra fuel tank. I suspect this was a normal adaption, like drop tanks in WW2. For the Zep raid to reach the target with what little bomb load they had. For the Zep chasers, once aloft, they pretty much were on their own as far as guidance, looking for either eyes on target or indicators (Search lights, flashes, bomb bursts) which would require an increase in endurance. I think you could make the case that the command felt better to keep then in the air vs risk losing them in landing accidents on the hope they could be refueled and redirected to where the Zeps were last reported. I admit my logic maybe twisted, and when it comes to the military, logic is not always the first concern, but, aircraft performance, and the level of skill of the pilots would seem to support the spare tank. As for why the tank is not seen in the post crash photos, either the Huns pulled it out, or it may have been ejected in the crash. Could the Avro have made the flight to the target and back without the spare tank?
As for cowling, from the front it looks like a cup cake in a cake box. The cowling much larger then the engine.
