It seems that the thread has more or less now gone full circle, with interesting and pertinent deviations here and there.
The motion ‘deviation’ showed a general issue with simulation and motion specifically. All motion systems algorithms (quite nicely described in previous posts) basically fool or trick our balance sensors, the very same sensors we are training pilots (in FSTDs) to ignore and of course ignore in actual flight!
Some 7 years ago when the LMfC motion (as it was called then) ‘enhancement first raised its head it generated a lot of debate within this industry. (The major manufacturers were already having ‘issues’ with the FFT concept at that time and this was viewed by many as another unwelcome intrusion). The following extract was sent to me and I think it is as pertinent today as it was then;
“Simulation lacks the rigour of other aeronautical disciplines and this is a very good illustration of my concerns with flight simulation. Quite possibly, the Belgians are wrong, but there is nothing that you can put forward to show or prove they are wrong. Moreover, their motion system may be less exact but actually lead to more effective training - we just don't know. But, to say that other simulators are more modern and therefore better or to say that you flew a simulator last week that felt good is not factual evidence - it's yet more subjective opinion and one opinion is then no more accurate or relevant than another.
All the time simulation backs off from doing real research it will suffer from this sort of stigma and we will have a discipline founded on nothing more than common sense and gut feel, with a few long technical words spread around to give the air of respectability."
What is certainly true today is that under current EASA and I assume FAA regs, there is still no requirement for any objective testing of motion systems (other than technical performance, vibs and latency). Every motion cue on a current Level C/D simulator is still only assessed subjectively!
ICAO 9625 Edition 3 does address this issue with both frequency and time domain objective testing BUT neither EASA nor the FAA have any plans to adopt Ed 3 in the foreseeable future.
I’m not going to repeat myself on the fidelity issue other than to reiterate that there really is no excuse with todays Level C/D FSTDs for anything less than perfection with systems simulation and performance within the normal envelope (within the confines of the obvious technical limitations).
There will be an issue with older FSTDs and hard and/or costly choices will need to be made. Excuses such as data or against our training policy are not limitations.
The FAA notice, whilst welcome will not in reality do anything to address the majority of the concerns raised here and with all the regulatory agencies being so ponderous it will not effect any changes until the next decade anyway.
Data does already exist to address many of the issues, the regulations are already there to be enforced and to quote AirRabbit “the handling qualities of today’s simulators is pretty darn good”
Better initial testing, more rigorous evaluations by both the operator and the qualifying body and the end User being more prepared to write up any defect not just accept them would go a long way.