Rotation

"Mxsmanic" wrote in message

Do real aircraft abruptly pitch upward on take-off during rotation,

Large jets seem to do the same thing, but at a slower speed.

Almost every aircraft I've flown has required nose down trim after takeoff.
Not abruptly, not drastically, but promptly after takeoff, as the craft
accelerates and you transition to climb, you always have to trim it down.

Another thing to consider in real aircraft is a plane trimmed for
takeoff for forward CG limit while the CG is loaded close to the aft
limit. The plane can be noticeablly more pitch sensitive during
takeoff.

The cure is to trim to the forward edge of normal take off trim
setting, and prepare for a light yoke force needed for rotation.

Robert M. Gary wrote:
Only if its out of trim.

buttman wrote:

Anyways, whats with the trend around here amongst the "regulars" to be
so condescending when dealing with people of lesser knowledge?

Msxmanic, in his introductory posts here, put forth several
aviation-specific claims, such as "the majority of airplane accidents are
caused by poor communication," then, when repeatedly questioned about these
claims, failed to provide any evidence whatsoever.

Tom provided the thread titles. If you are interested go to Google groups
and form your own first impressions of this individual's posting style.

--
Peter

Robert M. Gary writes:

Only if its out of trim. Make sure you are trimmed for take off and the
elevator is neurtral. Not sure how you do that in MSFS though, in a
real plane you let it go where it wants to go (which is based on the
trim).

MSFS will let me adjust trim. How do I find out how to trim for
take-off?

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"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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Mike Rapoport writes:

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.

I've been leaving the trim neutral. Rotation is sluggish up to a
certain speed, then the plane pitches up rapidly if I try to rotate
beyond that speed. Thereafter, I must push on the stick to keep the
pitch angle within reason.

I take it that I should trim to hold the nose down a bit?

It just surprises me that the plane pitches up so quickly
(particularly the Baron 58). If I know it's going to do this, I can
adjust the stick as soon as the nose rises, but I was wondering if the
real aircraft would behave in the same way. I don't see small planes
taking off like that when I observe them from a distance.

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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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John Gaquin writes:

Almost every aircraft I've flown has required nose down trim after takeoff.
Not abruptly, not drastically, but promptly after takeoff, as the craft
accelerates and you transition to climb, you always have to trim it down.

I'll try this. In the past, I haven't used trim much.

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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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