Timothy
Your post has been up nearly two days and this is the first reply so perhaps that gives you a clue that many will be shaking their heads on reading it and thinking that what you are planning to do is a fairly advanced handling exercise which could go seriously wrong – but then you do appear to realise some of the issues. But not I suspect all of them.
It would be very easy to just say ‘Don’t do it’ because that is sound advice and really the best given that I know nothing about you or your aeroplane – and please don’ take that as implying you might be an incompetent idiot. Literally I have no information other than your post with which to form an opinion.
On the other hand me just saying ‘Don’t do it’ is not terribly helpful. So without in any way encouraging you to ‘have a go’ may I make some comments?
You talk of cutting the engine. I presume you mean chopping the throttle rather than turning off the fuel – which would NOT be on. Chopping the throttle will still give the engine something to think about from a thermal shock point of view and is not without the potential to do harm, especially if it was repeated over and over in a test programme of many points. How much harm I am not competent to say and anyhow it would depend on the power that you normally use in these photo turns.
Even if you decide that is not enough to stop you going ahead, then forget turns and handling issues for a moment and ask yourself how will the aircraft behave at the speed you do your photo turns if you chop the power with wings level? How much slip is involved? What will the fin think of this? It might all be very benign from a structural standpoint but I don’t see how you can be sure of that without flight test instrumentation.
You are right to be concerned about a real inside engine cut when doing your turns. My answer to that concern is that you should mentally rehearse what you would do in such an event before orbiting your target. I would aim to instinctively chop both throttles at once, start rolling to wings level and then feed up power to cruise away and sort out the relevant check lists. It is a bit like sitting on the runway before EVERY twin take-off and getting in the right frame of mind to cope with an engine failure just as if you are about to do an engine failure test ride. You are NOT sitting comfortably, you are not relaxed and looking forward to the trip, you are in fact handling a loaded gun and very much aware of that.
In your case, unless these tests are carried out with the most violent engine cut and under g and high alpha which will exacerbate the roll with yaw issue, then there is not much point to doing them at all as you will only finish up kidding yourself there is no problem with your turns.
But if on the other hand you do find an inside cut is a very bad scene then ask yourself what are you going to do with this information? Stop taking pics?
Right now you feel there could be a problem and that is good – so address it like every take-off and stay ahead of the game
Cheers
JF
PS When you get old things don’t work as well as they did and so you ask the doc for this test or that. He then says do you really want to know that information? If the result it is not what you want to hear there would be nothing I could do about the condition so why find out?