It wasn't a politically correct answer - just the truth based on years of experience. When NVG were introduced we saw them used by some to push on in worse weather at night than they might have done in non-NVG flight - if you can see more you will go further.
As much information as you present to the pilot in the cockpit, if they are not trained to use it properly and believe in it then it won't prevent somatogravic or visual illusions fooling their brain.
I would always have an AI in a VFR aircraft for that just in case moment - better to have it and not need it than to need it and not have it.
A standard instrument fit is more than enough to prevent or overcome the leans but you have to believe the presentation - that comes down to training, exposure to real IMC and practice.
If you push the limits and go scud running, and you don't have the skills or knowledge to execute a plan B when it goes wrong then WTF are you doing in a cockpit in the first place?
Here is the thing: Why isn't there spatial disorientation as long as we look at the very big screen called "windscreen", with good visibility outside? We understand that illusion and contradictory (ie wrong) information from the vestibular system is very powerful and is most difficult to overcome, even by IFR trained pilots. Yet, the moment there is a good visual baseline (ie, VMC), no pilot complains about spatial disorientation.
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- Or have you ever seen *any* pilot levelling out - in VMC - after a 180 deg turn say: "Jesus, I can't believe I am wings level, it feels like I am now banking to the opposite side, my windscreen must be wrong, the horizon is not level, let me just spiral down to the ground, because it feels better."?
- Have you ever seen a pilot accelerating, with the horizon line clearly in front of them, saying: "Wow, my senses tell me I am zooming up, soon I must be stalling. The windscreen in front of me is obviously wrong. The ASI must be bugged too. Let me just push the stick further forward to avoid the stall."?
Yet in the two above scenarios, obviously the same presumed powerful misleading information is fed by the vestibular system to the brain of the pilot (leans, and somatographic illusion respectively), which in the absence of a good visual picture would be experienced as "overpowering" and - unless very well trained and recent - would be very difficult of fight. (I am referring again to the
very good article from Elan Head)
The obvious answer is that there is a tipping point at which too little vision information (read: degrading visibility) makes the brain remove the checks and balances that it normally subjects the vestibular system to. In the absence of anything else, the brain then takes the vestibular information on face value, and promotes it to "100% reality", with devastating effects (WYSIAYG - "What you see is *all* you get", Daniel Kahnemann, Thinking Fast, Thinking Slow, 2011, if you want to brush up a bit on the cognitive science behind all this).
Conversely, there is a tipping point at which feeding the brain increasing visual information will allow the brain to (effortlessly) put the 'genie back into the bottle', where the brain can demote the vestibular information to the more support function that is meant to occupy.
There is no principal reason why synthetic vision cannot achieve this. The question can only be, how realistic, how trustworthy, and how big this screen must be?
Originally Posted by
JimEli
While there is belief that synthetic vision technology may provide improvements in SD recovery, the real benefit from SV is improving situational awareness, workload reduction (i.e. terrain and path-in-the-sky) AND UPSET PREVENTION.
We now have thousands of hours of GA aircraft flown under VFR with some sort of synthetic vision on board. Be it tablet apps like the ones from Helios Avionics, Garmin or Foreflight, getting attitude information from an external AHRS (and in same cases, directly from the sensors built into the tablet), or panel mounted EFDs, be it certified or non-certified.
Observing pilots flying with these tools, as crude as they may still be at this time, there is no doubt in my mind that even a mini tablet-sized synthetic vision screen in front of the pilot can significantly reduce workload. It can give the pilot the confidence to reject wrong vestibular information, to remain calm and avoid the panic that leads to pilot induced upset.
To give an example: It makes a big difference when flying into a big black hole at night, to know whether the space in front of you is empty sky, a mountain, or a cloud obscuring the view on other aircraft, cultural light, terrain or the horizon lying behind it. Knowing the real world outside is still the same, even if momentarily it's all black, or all white, allows pilots to avoid giving in to illusions, such as false horizons or autokinesis, etc.
While in the mishap discussed in this thread many other things could have prevented the accident (seeing that the PIC was instrument rated, very experienced, had auto-pilot in his ship, and the operation benefited from operational oversight and safety management that comes with being a commercial charter operation), I reckon that even a much less experienced pilot could have extracted themselves out of this situation, simply by consistently using synthetic vision even in the cheapest available form.