VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.


Go Back   VAF Forums > Model Specific > RV-12/RV-12iS
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-28-2016, 06:45 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,563
Default Using Elevator Trim Indicator to Full Advantage

Until recently I have been using the elevator trim indicator on the D-180 to set and verify only takeoff trim position. Once airborne I would make trim adjustment for cruise and decent strictly by feel, which required many small, step adjustments to reach hands-off pitch stability.

I have made mental note of where trim indicator needs to be to satisfy cruise and power-off glide with full flaps deployed. Now when I change from climb to cruise and from cruise to decent I can quickly attain stabilized flight in pitch by setting the elevator trim by visual reference to the trim indicator. By roughing-in the trim setting visually I can attain desired pitch stability quickly with just a few small step adjustments and thus minimize workload.

So for what its worth (and maybe I’m just late to the party as usual) I thought I’d pass along this revelation as I gracefully age in my love of flying…

-
__________________
-
Jim Stricker - EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 750

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father - CFI) - USAAF 1st Lt. Captain B-17H

Last edited by Piper J3 : 09-28-2016 at 06:48 AM.
Reply With Quote
  #2  
Old 09-28-2016, 11:14 AM
rvbuilder2002's Avatar
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,662
Default

Based on the location you are indication for cruise trim and the position of your take-off trim indicator, I would say that your indication is not properly calibrated.
The take-off indicator is normally about 1/8" below the mid point mark, and cruise position is typically about 1/4 of the way up from the bottom.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Hubbard, Oregon
Van's Aircraft Engineering Prototype Shop Manager
FAA/DAR
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #3  
Old 09-28-2016, 11:28 AM
KALEWIS's Avatar
KALEWIS KALEWIS is offline
 
Join Date: Nov 2009
Location: Jackson, OH
Posts: 491
Default

Ditto on what Scott said. That's exactly how ours is trimmed.
__________________
Airspeed, Altitude, or Brains...you need at least two

RV-12 #328
At 630 Hrs on the Hobbs
Reply With Quote
  #4  
Old 09-28-2016, 02:29 PM
DHeal DHeal is offline
 
Join Date: Sep 2006
Location: Windsor, California
Posts: 1,005
Default

Ditto what was said above. I use the trim indicator bar to initially set my trim for takeoff. After that, I virtually never look at the trim indicator again during flight. I suggest that one should be trimming in-flight to remove control pressures from the stick -- not pre-setting the trim for a future flight condition or "flying " the plane using the trim alone. During my application of flaps, I position the flap handle and then initially adjust the trim by pushing the trim switch and counting a suitable number of seconds - then fine-tune it if needed to achieve the desired airspeed and control pressure. Works for me!
__________________
David Heal - Windsor, CA (near Santa Rosa)
EAA #23982 (circa 1965) - EAA Technical Counselor and Flight Advisor; CFI - A&I
RV-12 E-LSA #120496 (SV w/ AP and ADS-B 2020) - N124DH flying since March 2014 - 1,080+ hours (as of Oct 2021)!
VAF donation through June 2022.
Reply With Quote
  #5  
Old 09-28-2016, 02:31 PM
BobTurner BobTurner is offline
 
Join Date: Dec 2011
Location: Livermore, CA
Posts: 7,857
Default

As noted, the cruise position will vary with how much and where you are carrying passengers or baggage, as well as airspeed.
Reply With Quote
  #6  
Old 09-28-2016, 04:23 PM
PilotBrent PilotBrent is offline
 
Join Date: Dec 2011
Location: Hackettstown, NJ
Posts: 475
Default

Quote:
Originally Posted by DHeal View Post
Ditto what was said above. I use the trim indicator bar to initially set my trim for takeoff. After that, I virtually never look at the trim indicator again during flight. I suggest that one should be trimming in-flight to remove control pressures from the stick -- not pre-setting the trim for a future flight condition or "flying " the plane using the trim alone. During my application of flaps, I position the flap handle and then initially adjust the trim by pushing the trim switch and counting a suitable number of seconds - then fine-tune it if needed to achieve the desired airspeed and control pressure. Works for me!
I generally agree with that too. Would add that after putting in the first setting of flaps in the pattern I move the trim to the takeoff position which usually fully removes pressure from the stick - if I have to do a go around, I want the trim setting for takeoff to eliminate the need to adjust it when I'm focused on climbing out.
__________________
---------------
Brent Connelly
Hackettstown, NJ
RV-12, N913BC
2021 VAF Donation, please make yours too!
http://www.mykitlog.com/brent45

Check out & subscribe to my Youtube channel for latest RV-12 flying videos...
https://www.youtube.com/channel/UCxQ...Px2I7jmazGdLqg
Reply With Quote
  #7  
Old 09-28-2016, 05:46 PM
Phantom30's Avatar
Phantom30 Phantom30 is offline
 
Join Date: Jul 2009
Location: Coeur d'Alene, ID/Casa Grande, AZ
Posts: 654
Default

Quote:
Originally Posted by PilotBrent View Post
I generally agree with that too. Would add that after putting in the first setting of flaps in the pattern I move the trim to the takeoff position which usually fully removes pressure from the stick - if I have to do a go around, I want the trim setting for takeoff to eliminate the need to adjust it when I'm focused on climbing out.
Ditto...if something happens, I want to be set up for go around. Full throttle drop one notch of flaps; eyes on my route out!!!
__________________
Ric Dickison
307 (CAB) Phantom
Search and Destroy (Can
Tho RVN)
Distinguished Flying Cross Society Member
CH-47 & UH-1H "Driver"
Rotax 9 Series Service IRMT

RV-12 Kit#729 "N312RD" is now a full functioning fun machine!! Thanks Van for fulfilling my dream😎
2018 Dues Paid
Reply With Quote
  #8  
Old 09-29-2016, 04:47 PM
sblack sblack is offline
 
Join Date: Dec 2009
Location: Montreal
Posts: 1,520
Default

Quote:
Originally Posted by Phantom30 View Post
Ditto...if something happens, I want to be set up for go around. Full throttle drop one notch of flaps; eyes on my route out!!!

Does that result in being out of trim with landing flap and approach speed? If so, are you pushing or pulling on approach?
__________________
Scott Black
Old school simple VFR RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2020
Instagram @sblack2154
Reply With Quote
  #9  
Old 09-29-2016, 04:51 PM
sblack sblack is offline
 
Join Date: Dec 2009
Location: Montreal
Posts: 1,520
Default

I would add that the trim setting for take off will vary considerably with CG. On big airplanes there is a "green band" which covers the full CG range. if you are in that band your stick forces will be acceptable if your CG is anywhere within the envelope. If you set your trim based on a chart in the AFM you will be bang on at V2+something, the all engine safety speed. So there isn't one setting that is good for all conditions.

The trim should be set to trim the airplane at your best climb speed, although again it will vary with CG somewhat so some adjustment will be required. But for takeoff, especially with a tandem RV (4 or 8) where the CG variation is large, the takeoff trim setting will only be a guideline.
__________________
Scott Black
Old school simple VFR RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2020
Instagram @sblack2154
Reply With Quote
  #10  
Old 09-29-2016, 05:35 PM
Phantom30's Avatar
Phantom30 Phantom30 is offline
 
Join Date: Jul 2009
Location: Coeur d'Alene, ID/Casa Grande, AZ
Posts: 654
Default

Quote:
Originally Posted by sblack View Post
Does that result in being out of trim with landing flap and approach speed? If so, are you pushing or pulling on approach?
Hasn't caused me any problems.. I find the control force so light..not an issue. Take-off trim setting has worked fine in all cg configurations for me.

The -12 is about as easy to fly as any plane.
__________________
Ric Dickison
307 (CAB) Phantom
Search and Destroy (Can
Tho RVN)
Distinguished Flying Cross Society Member
CH-47 & UH-1H "Driver"
Rotax 9 Series Service IRMT

RV-12 Kit#729 "N312RD" is now a full functioning fun machine!! Thanks Van for fulfilling my dream😎
2018 Dues Paid
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 04:21 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.