Cessna 152 Rudder trim adjustment?

George Patterson wrote:
Qansett wrote:


I flew C150's and C172's in the early 1970's. none of them had
rudder trim.


Most of the 150s and all of the 172s I've flown had a rudder trim tab.

All the 152's have 'em as do the later 172's. The early 172's (even
after they went to the swept tail) don't.

GEG wrote:
Hi Folks,

I'm a low-time (10 hour) student pilot.
I took my first flights in my school's 152 about 2 years ago, then
had
an 18-month wait for various reasons.

When I first flew the plane, I don't remember the right rudder being
such an issue (I flew 3 times 2 years ago).

Now, the right rudder needs a lot of attention, almost all the time.
Even in straight and level at cruise, some right rudder needs to be
in.

So, before a know-nothing student says something to the instructor, I
wanted to give a shout to you guys and see what your thoughts
might be.

I understand the 152 has more need for right rudder than other
planes.
Have others had this experience?
What should I look for?
What should I say - if anything?

I know it's not "no rudder needed", maybe I'm just not a very good
pilot
yet.

Thanks,

Gary

A little trick I used to use while instructing was to intentionally add
a little left rudder until the student got used to both looking at the
TC and to get in the habit of keeping everything coordinated (this
worked a little better when I was MEIing). This may be what your
instructor was doing.
That or the trim tab needs some tweaking.

He was not.
It's also been noticed by a couple of other people now.

Before someone bends trhe rudder trim tab - they should make sure the
coupling links to the nose wheel steering are set correctly first.

My 172M links were set up incorrectly by what I otherwise consider a
reputable shop. The Cessna service manual states specifically not to
adjust these links just to make things fly straight. It may even have
come from the factory screwed up.

The Cessna mechanic needs to pay attention to the service
manual when troubleshooting badly rigged rudders. The rudder trim tab
has limited authority, and the pilot shouldn't have to hold large
amounts of pedal even if the tabs is off some. There are three possible
defects in this system:
1. A broken right rudder bar return spring. The left spring will pull
the left pedals forward and the pilot has to constantly hold right
rudder to fight it. These springs break rather often.
2. Someone may have fooled with the cable adjustments at the rudder to
center it. Those adjustments never need changing unless the pedals
aren't lined up when the rudder is centered. The rudder centering is
controlled by the nosewheel centering cam at the nosegear torque links,
and adjustments are made by changing the length of the nosegear
steering spring rods.
3 Everything might be OK but someone has bent the rudder trim tab the
wrong way altogether. To get right trim, the tab has to bend left.

The service manual rigging procedures are a bit complex, and a lot of
mechanics just ignore them and end up misadjusting stuff. We've often
found all the control systems way out of whack, sometimes dangerously
so.

Dan

On Fri, 29 Apr 2005 09:28:20 -0400, GEG
wrote:

Hi Folks,

I'm a low-time (10 hour) student pilot.
I took my first flights in my school's 152 about 2 years ago, then had
an 18-month wait for various reasons.

When I first flew the plane, I don't remember the right rudder being
such an issue (I flew 3 times 2 years ago).

Now, the right rudder needs a lot of attention, almost all the time.
Even in straight and level at cruise, some right rudder needs to be in.

So, before a know-nothing student says something to the instructor, I
wanted to give a shout to you guys and see what your thoughts
might be.

I understand the 152 has more need for right rudder than other planes.
Have others had this experience?
What should I look for?
What should I say - if anything?

I know it's not "no rudder needed", maybe I'm just not a very good pilot
yet.

Thanks,

Gary

Are you a very, very heavy student pilot?

If not, the 152 should fly reasonably straight boots off the pedals.
You do have equal tank loads, I expect?

Brian W

5' 10", 155 lbs, including my brain (subtract 3 oz. when I leave that
behind!)
Instructor at 190 lbs.