Forum

Notifications
Clear all

This Forum is a place for Piper Comanche pilots to communicate and discuss technical issues

If you join or reset a password, please check your Spam Email box for emails from Admin at ComancheTechTalk.com

Please put your questions on the forum as well so everyone can read and respond. Someone else might be having similar questions.

All questions or topics on the Forums automatically get sent to the Tech team as well.

Trim Position Setting

1 Posts
1 Users
0 Reactions
161 Views
Admin
Joined: 5 years ago
Posts: 1162
Topic starter  

Trim Position Setting

Postby Warren Janzen » Mon May 22, 2017 4:41 pm

I have a 180 Comanche. While flying full tanks and just myself at
75% power, I noticed the trim position seems quite forward. Later
with a copilot along similar position. I might have 20 pounds in the baggage
compartment. Trim position at neutral for take off seemed normal.
See photo. Any advise?
Attachments
IMG_3767.JPG
Warren Janzen
 
Posts: 24
Joined: Fri Jun 27, 2014 11:28 pm

Re: Trim Position Setting

Postby LeWayne Garrison » Mon May 22, 2017 6:03 pm

The trim drum in the tail cone can be adjusted to give more available nose down trim. With that done, the trim indicator will move rearward and give you more adjustment in the trim.
LeWayne Garrison
 
Posts: 73
Joined: Tue Aug 16, 2011 3:37 am

Re: Trim Position Setting

Postby Larry Martin » Mon May 22, 2017 11:16 pm

I am noticing forward trim more forward of what I would have expected on a -30. Is there a "relative" position that one should expect prior to going through the expense of redoing the trim drum winding?
Larry Martin
 
Posts: 38
Joined: Wed Jul 13, 2016 6:51 pm

Re: Trim Position Setting

Postby LeWayne Garrison » Tue May 23, 2017 4:14 pm

In cruise the trim setting should be near the neutral range when the aircraft is loaded approximately at gross weight and in balance. The trim drum is easily accessible by removing the tail cone. The adjustment itself is also straightforward and should take no more than 30 minutes. All told, removing tailcone, adjustment and reinstalling tailcone, about 1 hr to 1.5 hours. Good time to lube everything back there anyway.
LeWayne Garrison
 
Posts: 73
Joined: Tue Aug 16, 2011 3:37 am

Re: Trim Position Setting

Postby Larry Martin » Thu May 25, 2017 2:48 am

Thanks LeWayne,

I'll check that out. I have a service manual and will follow the proceedure if the trim is out in cruise.

Larry Martin
 
Posts: 38
Joined: Wed Jul 13, 2016 6:51 pm

Re: Trim Position Setting

Postby Zach Grant L1011jock » Fri May 26, 2017 2:42 pm

The faster you go, the more forward the trim will be. You trim for a speed, so the faster airplanes will see the trim indicator show more forward trim settings in cruise and descent. The trim indicator is a separate lever arm and single cable that has a spring At the other end and shows actual trim linkage position. It is separate from the trim cable that goes around the crank and trim drum. Think about it this way. If neutral trim is good for takeoff and initial climb of about 100 mph, when you are cruising indicating 160+ Mph, the trim should be well forward of the neutral point! You won't run out of nose down trim if the plane is flown in the airspeed envelope and in CG unless something wrong. 180s show closer to neutral in cruise, twins show the most forward.

Zach

"Keep it above 5 feet and don't do nuthin dumb!"
User avatar
Zach Grant L1011jock
Technical Advisor
 
Posts: 1404
Joined: Mon Mar 22, 2004 4:35 pm
Location: Indianapolis KEYE

Re: Trim Position Setting

Postby Clarence Beintema » Sun Jun 04, 2017 5:11 pm

If you have a manual go through the procedure first and understand what is involved. You will need to build the stabilator rigging tool from the dimensions in the manual.

The basics are set the stabilator in the correct neutral position, set the trim drum in the correct neutral position and set the trim tab in the correct neutral position, set the trim position indicator in the correct neutral position.

Clarence

Clarence Beintema
ICS member
ICS member
 
Posts: 134
Joined: Tue May 11, 2010 11:41 pm

   
Quote
Share: