Simulated reality

Full flight simulators, even most of the latest ones, are still no good for learning to fly the aircraft manually. The simulator doesn’t feel like the real aeroplane. In fact it’s more difficult to fly than the real aeroplane.

Try carrying out a simulated landing in a high crosswind and see if you can keep the aircraft on the runway after touchdown. The way the motion system works, and the effect this has on the body’s sensitive balance mechanisms, induces over-controlling by the pilot.

All this may be of little relevance for experienced pilots doing recurrent training on a type they have been flying for some time, but for inexperienced pilots new to the type – the people who most need the training – simulated landings are no preparation for the real thing. Hence the need for expensive base training for new pilots – if the airline is prepared to fund it.

But what if simulators did feel like the real aeroplane? Then an airline could reduce the risk of expensive heavy landings.

I have flown such a system, and it was a revelation. The motion-modifier system, known as LM2, was invented by a Belgian pilot.

Now I have just flown another system that feels pretty much like the real thing, this time invented just across the border in the Netherlands by a new simulator company that has now been bought by Lockheed Martin.

On a visit last week to Lockheed Martin Commercial Flight Training at Sassenheim, I “flew” a simulator without any pre-briefing about its new motion system. The device was a Boeing 767-300F with what looks like a 787 cockpit – being prepared for customer FedEx.

I only had a brief ride in the new 767 simulator with no idea of what to expect. The “aircraft” was set up to be very light – no freight, very little fuel – so it leapt down the runway like a greyhound out of the traps.

I responded to the instructor’s rotate call and found the 767 needed a pitch attitude of nearly 20deg to maintain the climb speed, but despite how fast things were happening I felt strangely at ease, and quickly settled the correct attitude and trimmed to it. Over-correcting in an unfamiliar simulator is easy to do, but it just wasn’t happening.

The instructor suggested I try banking in the climb, so I went about that in a fairly military manner, invoking “bank angle, bank angle” alerts, but taking no notice. Again I noticed that despite the rapid application of bank, then reversing it several times, there was none of the feeling of “wallowing” that simulators normally generate under such circumstances.

Since we only had use of the simulator for a very short time the instructor put us on approach, pre-aligned with the left of a pair of parallel runways and on the ILS. I elected to ignore the ILS, carry out a visual approach, and manoeuvre to land on the right runway, using the precision approach path indicators for glideslope guidance. Again, despite the S-turn involved in lining up with the right runway, there was no wallowing motion nor tendency to over-correct. Then the aircraft settled, trimmed, onto the extended centreline and the landing was firm but straight, with no trouble maintaining the runway centreline.

I always dread transferring to the nosewheel tiller in a simulator, because over-correction on the tiller (for me) is almost inevitable while taxiing. But this time there was none of the lurching that induces that reaction.

I was naturally inclined to attribute my performance to skill, but speaking to the engineers immediately afterwards I learned about the motion system changes.

It was my first exposure to an electro-pneumatic system, and the lack of lurching and overcorrection was partially the result of this systems’s smooth motion delivery, but also partly due – they told me – to a modification to the algorithms that determine “wash-out” – the need for a simulator to return – supposedly imperceptibly – to a stable state after simulating an accelerated manoeuvre. The trouble is that the body’s inner-ear balance sensors cannot be fooled – they notice the artificial motion wash-out and are confused by it.

But in this case the wash-out was almost imperceptible, making the simulator feel like a real aeroplane. My only caveat here is that my trip was very brief – I couldn’t put the machine through a wide range of manoeuvres to check them all. I know what I felt, however, and this machine felt good.

This issue of motion systems fidelity is not trivial, but somehow the training industry and even the regulators act as if it is. Really good motion systems have the potential to improve pilot training enormously while keeping training costs down.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s