Rotation

"Mxsmanic" wrote in message
...

Do real aircraft abruptly pitch upward on take-off during rotation, or
is this an artifact of my simulator? I find that I must put the stick
forward slightly as soon as the nose rises, or I risk a tail strike.
This is especially true on small aircraft, such as the Baron 58.
Large jets seem to do the same thing, but at a slower speed. I am
curious as to whether real aircraft are the same way, and if so, what
the proper way is to rotate to minimize wild movements.

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You may be rotating with too high velocity or out of trim.

Real airplanes are designed to be stable, both static and
dynamically. Simulators are designed to be less stable in
order to make the "student" work harder at the scan and
control inputs. A $10,000,000 full motion simulator [for a
$5,000,000 airplane] flight parameters are very close to a
real airplane as far as static and dynamic stability,
break-away forces and momentum.

Some real airplanes sit with the wing at a negative angle of
attack on the ground and must be rotated to a positive AOA
for take-off, perhaps to 15 degrees nose high for some jets.
This is a smooth but brisk pull, new pilots in type often
over-shoot the target rotation. Most light aircraft sit on
the ground at a positive AOA and will take-off with very
little elevator input if they are loaded and trimmed for
take-off.

The top of the line simulators can be made to fly just like
the real thing, because the software and hardware is top
line. Your desktop PC based training device uses consumer
grade mechanical parts.


"g n p" wrote in message
news:1157975462.625535@athnrd02...
|
| "Mxsmanic" wrote in message
| ...
|
| Do real aircraft abruptly pitch upward on take-off
during rotation, or
| is this an artifact of my simulator? I find that I must
put the stick
| forward slightly as soon as the nose rises, or I risk a
tail strike.
| This is especially true on small aircraft, such as the
Baron 58.
| Large jets seem to do the same thing, but at a slower
speed. I am
| curious as to whether real aircraft are the same way,
and if so, what
| the proper way is to rotate to minimize wild movements.
|
| --
| Transpose mxsmanic and gmail to reach me by e-mail.
|
|
| You may be rotating with too high velocity or out of trim.
|
|

"Jim Macklin" writes:

The top of the line simulators can be made to fly just like
the real thing, because the software and hardware is top
line. Your desktop PC based training device uses consumer
grade mechanical parts.

The joystick works very well once the plane is in the air, so the
problem is unrelated to any deficiency of the joystick.

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Depends on where you have the trim set which is always a compromise. If the
trim is set so that there is no nose down trimming required after takeoff,
then it will take quite a bit of pull to get the aircraft to rotate and in
the initial climb. If the aircraft is trimmed so that only a moderate
amount of force is required to rotate then it will require pushing on the
yoke and retrimming after takeoff as the airplane accelerates.

The trim setting is correct for one speed and configuration (power and flap)
and since the airplane is accelerating, the trim is going to need to be
changed.

Mike
MU-2


"Mxsmanic" wrote in message
...
Do real aircraft abruptly pitch upward on take-off during rotation, or
is this an artifact of my simulator? I find that I must put the stick
forward slightly as soon as the nose rises, or I risk a tail strike.
This is especially true on small aircraft, such as the Baron 58.
Large jets seem to do the same thing, but at a slower speed. I am
curious as to whether real aircraft are the same way, and if so, what
the proper way is to rotate to minimize wild movements.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mike Rapoport wrote:
Depends on where you have the trim set which is always a compromise. If the
trim is set so that there is no nose down trimming required after takeoff,
then it will take quite a bit of pull to get the aircraft to rotate and in
the initial climb. If the aircraft is trimmed so that only a moderate
amount of force is required to rotate then it will require pushing on the
yoke and retrimming after takeoff as the airplane accelerates.

The trim setting is correct for one speed and configuration (power and flap)
and since the airplane is accelerating, the trim is going to need to be
changed.

Mike,
I think trim is just academic is MSFS because there is no control
feedback. The OP is probably setting the elevator with too much back
pressure but doesn't know it because he doesn't have the feedback.
Honestly, if you asked me what position the yoke is in on take off, I
probably couldn't tell you. In real life we expect the yoke to go to
its trim position, something that doesn't make sense in a simulator
that does not have feedback controls.
-Roebrt

Robert M. Gary writes:

I think trim is just academic is MSFS because there is no control
feedback.

You don't need control feedback to see the response of the aircraft
out the window and with the instruments, although you can get it with
a force-feedback joystick. It is true that anything that requires
gradual control inputs or depends on a sensation of motion or other
physical feedback is difficult to simulate without advanced hardware.

The OP is probably setting the elevator with too much back
pressure but doesn't know it because he doesn't have the feedback.
Honestly, if you asked me what position the yoke is in on take off, I
probably couldn't tell you. In real life we expect the yoke to go to
its trim position, something that doesn't make sense in a simulator
that does not have feedback controls.

You're saying the yoke moves on its own?

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"Mxsmanic" wrote in message

You're saying the yoke moves on its own?


In an actual aircraft, yes -- in a manner of speaking. At a point on the
takeoff roll prior to actual takeoff, the elevator (or stabilator) starts
to "fly"when it acquires enough airflow to force a response. When that
happens, the yoke will move from wherever it was (usually full down in small
planes with manual controls) to whatever position is defined as neutral for
that particular speed, as determined by the trim tab setting.

John Gaquin writes:

In an actual aircraft, yes -- in a manner of speaking. At a point on the
takeoff roll prior to actual takeoff, the elevator (or stabilator) starts
to "fly"when it acquires enough airflow to force a response. When that
happens, the yoke will move from wherever it was (usually full down in small
planes with manual controls) to whatever position is defined as neutral for
that particular speed, as determined by the trim tab setting.

That seems logical. Unfortunately my joystick has only springs for
feedback, and that feedback is fixed.

However, I do notice a change in the view out the window and sometimes
the artificial horizon as speed increases, if I have the stick
substantially forward or backward, so the effects are indeed being
simulated, even if I can't feel them.

I suppose force-feedback might help, but I don't know how reliable or
durable those are, and they can be expensive (and they are hard to
find).

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"Robert M. Gary" wrote in news:1157992218.361147.166330
@d34g2000cwd.googlegroups.com:

Snipola
Mike,
I think trim is just academic is MSFS because there is no control
feedback. The OP is probably setting the elevator with too much back
pressure but doesn't know it because he doesn't have the feedback.
Honestly, if you asked me what position the yoke is in on take off, I
probably couldn't tell you. In real life we expect the yoke to go to
its trim position, something that doesn't make sense in a simulator
that does not have feedback controls.
-Roebrt

I have a force feedback stick and if I don't trim right for
the phase of flight I'm in I have to provide excessive input
to maintain flight attitude. As I adjust the trim the feedback
moves the stick. Trim buttons are on my stick. I can press
them while lightly holding the stick and feel the stick move.
I know I am in trim when the stick is centered and I have a
feather touch on the stick.

When properly trimmed I can let go of the stick and maintain
flight attitude for 10's of seconds. I can even conrol climb
and descent with power adjustment without ever touching the
elevator. Or sometimes I maintain altitude with single clicks
of trim.

Before I got the force feedback stick, trim didn't make sense
since you couldn't feel it in the controls.

The hundred bucks I spent on mine were well worth the enhanced
simulation experience. Flight is much smoother and landings
are greased much more often.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
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Skywise writes:

Before I got the force feedback stick, trim didn't make sense
since you couldn't feel it in the controls.

The hundred bucks I spent on mine were well worth the enhanced
simulation experience. Flight is much smoother and landings
are greased much more often.

What brand and model of stick was this? And has it been reliable?

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