How much do you trim?

Robert Chambers writes:

The discussion of trim in a flight sim on a PC is academic.

Hardly. Trim does the same thing on a simulator that it does in real
life.

In an aircraft, trim is not so much a "convenience" as you seem
to think.

A lot of aircraft and pilots seem to do without it, so obviously it is
not necessary.

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On 2006-10-09, Mxsmanic wrote:
Robert Chambers writes:

The discussion of trim in a flight sim on a PC is academic.

Hardly. Trim does the same thing on a simulator that it does in real
life.

Not really. In a real aircraft, you trim out the forces you're feeling
without actually moving the control itself.

However, controls for a PC don't work like this - so you have to feed in
trim to the simulator, while gradually moving the joystick to the centre
position - because all that's providing resistance is a set of static
springs.

It would be possible to design flight controls for a PC simulator (which
are inadequate on so many levels - even the expensive ones) which work
just like trim works on a real aircraft, but it would be extremely
expensive. The other problem with PC controls is that they don't move
nearly far enough. The CH yoke for example, goes in and out (for pitch)
about 3 or 4 inches, and turns about 45 degrees in each diretion. The
yoke on a Cessna 172 has probably 18 inches of fore/aft travel and turns
through about 120 degrees in each direction. CH rudder pedals maybe
displace an inch or so, but the rudder pedals on a C172 probably
displace a good 5 or 6 inches. This means that the controls on a
simulator are _insanely_ sensitive if you want them to be able to make
full control deflections.

In an aircraft, trim is not so much a "convenience" as you seem
to think.

A lot of aircraft and pilots seem to do without it, so obviously it is
not necessary.

Name ten!

If you're doing without trim in a real aircraft, you _are_ doing it
wrong, at least for any conventional light plane right up to airliners.
Trim is absolutely essential in pitch.

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Dylan Smith writes:

This means that the controls on a
simulator are _insanely_ sensitive if you want them to be able to make
full control deflections.

And the cheaper the controls, the worse they are. I tried a cheapo
joystick today and almost dived into the ground. I don't think it
moves more than a quarter of an inch from stop to stop for control
surfaces.

Name ten!

Anyone who flies an aircraft that doesn't provide trim.

Trim is absolutely essential in pitch.

I just worry about not knowing how far away I am from neutral. I
could be applying enormous control surface deflection with trim
without necessarily being aware of it. So I might try to move a bit
further with the yoke and find that I'm already against the stop.

The other thing that worries me is distraction. Takeoffs, landings,
climbs, and approaches seem like bad times to be fiddling with trim,
although I suppose that depends on where the trim controls are (I get
the impression that they are often in odd places).

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"Mxsmanic" wrote in message
news
Robert Chambers writes:

The discussion of trim in a flight sim on a PC is academic.

Hardly. Trim does the same thing on a simulator that it does in real
life.

In an aircraft, trim is not so much a "convenience" as you seem
to think.

A lot of aircraft and pilots seem to do without it, so obviously it is
not necessary.

--

No really they don't. Elevator trim is taught during your first lesson for
your Private certificate.

"Mxsmanic" wrote in message
news
Robert Chambers writes:

The discussion of trim in a flight sim on a PC is academic.

Hardly. Trim does the same thing on a simulator that it does in real
life.

In an aircraft, trim is not so much a "convenience" as you seem
to think.

A lot of aircraft and pilots seem to do without it, so obviously it is
not necessary.

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

They must be some really strong pilots... as not trimming a C-172 will give
your arms quite a workout and results in a lot of unnecessary work on behalf
of the pilot, and makes it harder to fly "smoothly and precisely" as you are
constantly "fighting" the force on the elevator control. I can tell which
the difference between approaches where I have the plane nicely trimmed on
on final and the ones where the plane is slightly out of trim, as on the out
of trim approaches I am having to "work more" than I need to and it takes
away from other things I need to be concentrating on to ensure a nice smooth
landing.

Wade Hasbrouck
PP-ASEL
http://spaces.live.com/wadehas

It totally depends on the plane. I used to fly a Globe Swift and I
never found any reason to need to touch the trim. The plane flew hands
off at whatever you pointed it to. I currently own a Mooney and I spend
more time in the pattern moving the trim than holding the throttle. The
entire downwind of a Mooney is rolling the trim back, slowing the plane
down.

Bottom line is that it depends on the design of the plane how sensitive
it is to trim and how much trim change it requires for any
displacement.

-Robert, CFII

Robert M. Gary wrote:
It totally depends on the plane.

Second that. The C150 I fly requires a lot less trim than the C172, to the
point that I forget to use it sometimes. The 172 really doesn't let me
forget.

Tom Young

Tom Young wrote:
Second that. The C150 I fly requires a lot less trim than the C172, to the
point that I forget to use it sometimes. The 172 really doesn't let me
forget.


I ferried a C-172 with a coworker up to an engine shop a few years ago as one of
a flight of two. When we got there, I got into the back of the other C-172.
After we took off, I carefully noted when the pilot trimmed the aircraft, then
leaned forward to engage the guys in the front in conversation. The pilot would
fly along for a minute or two, then retrim. I'd lean back and wait a few
minutes until he retrimmed yet again. Then I leaned forward to talk to the guys
up front again.... making cracks about his apparent inability to hold altitude.

Heh heh... I must have done it four or five times before the pilot caught on.
G Lucky for me, there was no ejection seat in the C-172.



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

Mortimer Schnerd, RN wrote:
Tom Young wrote:
Second that. The C150 I fly requires a lot less trim than the C172, to the
point that I forget to use it sometimes. The 172 really doesn't let me
forget.


I ferried a C-172 with a coworker up to an engine shop a few years ago as one of
a flight of two. When we got there, I got into the back of the other C-172.
After we took off, I carefully noted when the pilot trimmed the aircraft, then
leaned forward to engage the guys in the front in conversation. The pilot would
fly along for a minute or two, then retrim. I'd lean back and wait a few
minutes until he retrimmed yet again. Then I leaned forward to talk to the guys
up front again.... making cracks about his apparent inability to hold altitude.

Heh heh... I must have done it four or five times before the pilot caught on.
G Lucky for me, there was no ejection seat in the C-172.

I'd have pushed you out the door. I had a 260 lb friend who would wait
patiently until I got the plane trimmed and then slam his seat all the
way back. He did it so fast that I didn't see it coming.

This was the same guy who completely shut an engine down on me once.
I'm sure it was payback for something, I just can't remember what.

"Mortimer Schnerd, RN" mschnerdatcarolina.rr.com wrote in message
...
Tom Young wrote:
Second that. The C150 I fly requires a lot less trim than the C172, to
the
point that I forget to use it sometimes. The 172 really doesn't let me
forget.


I ferried a C-172 with a coworker up to an engine shop a few years ago as
one of a flight of two. When we got there, I got into the back of the
other C-172. After we took off, I carefully noted when the pilot trimmed
the aircraft, then leaned forward to engage the guys in the front in
conversation. The pilot would fly along for a minute or two, then retrim.
I'd lean back and wait a few minutes until he retrimmed yet again. Then I
leaned forward to talk to the guys up front again.... making cracks about
his apparent inability to hold altitude.

Heh heh... I must have done it four or five times before the pilot caught
on. G Lucky for me, there was no ejection seat in the C-172.
--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

About 3 months after I got my private certificate, I decided to go back for
a little XC with the CFI who had actually been my CFI at the time of my
checkride in order to just make sure I hadn't started to develop any early
bad habits.

As we were headed southeast from Phoenix, ATC called traffic overtaking us
from our six o'clock and co-alt (ATC was not talking to that traffic...)
Try as we might, we couldn't pick him up and eventually ATC suggests we
descend. Right before I reach to retard the throttle and before I can push
the nose down, my good old CFI racks the passenger seat back to the rear
stop and just flops the seat flat trying to look up through the rear
windows. We immediately gain about 150 feet which probably was not a good
thing since we were pretty sure the conflicting traffic was above and behind
us.

Scared the hell out of me and I didn't let him hear the end of it all the
way to our destination (and part of the way back, too...)

Jay B