Rudder for final runway alignment (?)

Peter Duniho writes:

What in the world does that mean?

It means that I do not take for granted that what I see out the window
is what I think I'm seeing, especially with respect to the aircraft's
attitude, speed, altitude, and so on.

No one is suggesting that one believe optical illusions and misleading
sensations over instruments. Those things simply aren't present during good
daytime visual conditions.

How do you know? The nature of illusion is that you don't know it's
an illusion until it's too late.

Again, please read what I wrote. The words I wrote are "NO NEED". I don't
see instruments as a need. For that matter, you do NOT see them as a
convenience...you have specifically written that you see them as a need.

I've written that they are more trustworthy than vision and
sensations. If there is a disagreement, the instruments are right.
If the instruments agree, no problem.

Relatively high.

Relative to what? Give me a number.

As in, any pilot with any reasonable amount of experience
has likely had at least one flight instrument fail during a flight.

Which instruments have failed for you, and over the course of how many
flights?

That's true. But they don't trick your sensation of acceleration.

But they do. They make you think you are strongly accelerating when
in fact you are not. For example, tilting the simulator so that the
net acceleration vector points a bit backwards gives you the
impression that the aircraft is accelerating "forward"; but in
reality, the total acceleration is still only 1 G, whereas it would be
more than 1 G in reality.

Then why don't you write about that, instead of making stuff up that has no
basis in facts?

See above.

Wrong. They get motion sickness for the very reason that their sensation of
acceleration is NOT being fooled.

No, they get motion sickness from visual input alone. The exact
mechanism is not fully understood.

The reason a person gets motion sickness is that their vision sends signals
of acceleration and other motion, while the sensory organs that provide
direct data of acceleration do not. The conflict results in the motion
sickness. If the simulator were effectively fooling all sensation of
acceleration, there would be no motion sickness.

Not true. Even when acceleration and visual input are perfectly
synchronized, motion sickness often results.

Again, how would you know whether that happens or not?

Because that's how simulators work.

With respect to returning to neutral position, if it happens quickly enough
(the one way to fool one's sensation of acceleration is to sneak up on it),
it does happen. This is not uncommon if the simulator gets frozen
mid-flight and reset, for example.

The simulator is always returning to a neutral position, because it
needs freedom of movement for the next acceleration. The only
exceptions would be where no acceleration in certain directions is
possible (e.g., downward acceleration on the ground).

The key is to accelerate quickly and then smoothly back off to more
than a stop, so that the simulator cabin returns to a neutral
position, ready for the next acceleration cue. There is very little
real acceleration, but the pilot's imagination will fill everything in
after that first little push.

As far as noticing the rotation, this is
accounted for in the motion of the simulator, and the rotation is combined
with the forward motion that obscures it from one's sensation.

It can't be accounted for; it's a limitation of full-motion
simulators. In real life, the acceleration vector moves, not the
pilot. In a simulator, the acceleration vector remains stationary,
and the pilot rotates. Unless the center of rotation is a great
distance away from the pilot, his equilibrium will note rotation, not
just acceleration. But usually the other cues will hide this minor
effect.

Why weren't you paying attention then? Why did you not notice that the
simulator pitches up even before the airplane itself has been pitched up?

I did notice that. That was self-evident, anyway, since that's the
only way to simulate the movement in question.

--
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