No, but I don't think that practicing for a failure of both systems at the same time has ever been considered prior to the last two weeks.
I have flown with the VSCS switched off though. There is certainly a yaw stability problem at high speeds but not at the lower speeds of a final approach where the VSCS loses its authority anyway.
My previous comments were a discusion about SB900-109R1. Forget the AD for the moment because that certainly complicates matters. I would not want to be flying anyway if I was subject to its requirements.
Lets put ourselves in a hypothetical situation where we are subject to SB900-109R1 only. We are flying along below 100 knots with the VSCS switched off. The revised SB no longer requires that the circuit breakers be pulled, so they are available to us. We suddenly diagnose a NOTAR problem.
Keep VSCS de−energized unless helicopter is experiencing a anti−torque system malfunction.
We immediately switch the VSCS back on and pray that we don't then get an adapter tube failure. I think the chances would be fairly remote. We then carry out the standard actions for a 'Yaw Control Failure'. The SB then says:
If there is a anti−torque system malfunction, de−energize the VSCS on final approach to a run on landing......
Now, I don't know why you would want to switch the VSCS back off at this point but that's what the SB says. Personally, I would leave them on rather than complicate the situation, particularly in a 'Right Pedal Forward' situation. I might consider it in a 'Left Pedal Forward' situation if everything else was going to plan, but why bother. As I said before, the VSCS have minimal authority at the lower speeds and I suspect that an adapter tube failure at that point would have little consequence anyway.
But,
anonythemouse, referring to the SB, asked the question "at what exact point of the final approach with a NOTAR emergency are you supposed to select the VSCS off?" You saw my comments, would you not agree?