VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 07-02-2012, 11:03 AM
PCHunt PCHunt is offline
 
Join Date: Feb 2007
Location: San Diego, CA
Posts: 1,670
Default

Vern: Good catch. However, the Trio is showing too much Right rudder, wouldn't that put the heading off to the right instead of the large left angle shown on the HSI?
__________________
Pete Hunt, [San Diego] VAF #1069
RV-6, RV-6A, T-6G
ATP, CFII, A&P

2020 Donation+, Gladly Sent
Reply With Quote
  #12  
Old 07-02-2012, 11:29 AM
ArVeeNiner's Avatar
ArVeeNiner ArVeeNiner is offline
 
Join Date: Jun 2006
Location: San Jose, CA
Posts: 1,125
Default

Quote:
Originally Posted by DFlyer View Post
A couple of comments. First, is that with the compass mounted in a magnetically clean area, and calibrated, it should be very accurate. And second, do you have a sliding canopy? If so, then you need to calibrate with the canopy slid forward. The frame of the canopy will magnetically interfere with the compass calibration when it is slid back.

-Robert
Dynon Marketing
Yes, I do have a slider and I had the canopy open during the cal. I'll try it again with the canopy shut.
__________________
Kelly Johnson
San Jose, CA
RV-9A

Pink slip issued: 5/7/12

First flight: 5/28/12, Memorial Day.

Phase I Complete: 8/18/12!

2020 donation: complete
Reply With Quote
  #13  
Old 07-02-2012, 11:32 AM
ArVeeNiner's Avatar
ArVeeNiner ArVeeNiner is offline
 
Join Date: Jun 2006
Location: San Jose, CA
Posts: 1,125
Default

Quote:
Originally Posted by vlittle View Post
When all else fails, check the obvious.

The slip indicator on your Trio indicates that you are flying with a lot of yaw.
this will cause your magnetic heading to disagree substantially with your ground track in zero wind situatons, thus indicating a crosswind.
Yes Vern, that is a good catch. I've been working to get the plane to fly straight and obviously, I'm not quite done. However, I have stepped on the rudder pedal and it doesn't make a significant difference concerning the Dynon issue.
__________________
Kelly Johnson
San Jose, CA
RV-9A

Pink slip issued: 5/7/12

First flight: 5/28/12, Memorial Day.

Phase I Complete: 8/18/12!

2020 donation: complete
Reply With Quote
  #14  
Old 07-02-2012, 12:22 PM
RVbySDI's Avatar
RVbySDI RVbySDI is offline
 
Join Date: May 2005
Location: Tuttle, Oklahoma
Posts: 2,563
Default

Quote:
Originally Posted by ArVeeNiner View Post
Yes, I do have a slider and I had the canopy open during the cal. I'll try it again with the canopy shut.
I am going to say this is your culprit. When you mounted the magnetometer in the location you chose did you take into consideration the slider frame? The slider frame is steal so if it is slid open and within close proximity to the magnetometer it will affect the reading. I bet you will see a difference when you recalibrate with the slider closed.
__________________
RVBYSDI
Steve
RV9A
https://rvwings.com

Live Long And Prosper! 🖖🏻
Reply With Quote
  #15  
Old 07-02-2012, 01:16 PM
BillC BillC is offline
 
Join Date: Mar 2005
Location: Ramona, Ca
Posts: 259
Default

Is that wind vector on the Dynon correct (205-216 deg @ 68-72 mph) ? With that much wind you would have to have the aircraft pointed in that direction in order to track the course on the bug.
__________________
Bill RV-9A Flying
FFI- Flight Lead
N99WC
Ramona, CA (KRNM)
Reply With Quote
  #16  
Old 07-02-2012, 01:55 PM
ArVeeNiner's Avatar
ArVeeNiner ArVeeNiner is offline
 
Join Date: Jun 2006
Location: San Jose, CA
Posts: 1,125
Default

Quote:
Originally Posted by BillC View Post
Is that wind vector on the Dynon correct (205-216 deg @ 68-72 mph) ? With that much wind you would have to have the aircraft pointed in that direction in order to track the course on the bug.
No, that's exactly the issue.
__________________
Kelly Johnson
San Jose, CA
RV-9A

Pink slip issued: 5/7/12

First flight: 5/28/12, Memorial Day.

Phase I Complete: 8/18/12!

2020 donation: complete
Reply With Quote
  #17  
Old 07-02-2012, 02:09 PM
RVbySDI's Avatar
RVbySDI RVbySDI is offline
 
Join Date: May 2005
Location: Tuttle, Oklahoma
Posts: 2,563
Default

Quote:
Originally Posted by ArVeeNiner View Post
No, that's exactly the issue.
The readout for wind speed will not be accurate if your magnetometer is not calibrated correctly. The calculations are using the magnetometer readings as one component of many in the formula. A small number variation from the magnetometer can cause a large deviation in wind speed numbers displayed. Do the re-calibration and test again.
__________________
RVBYSDI
Steve
RV9A
https://rvwings.com

Live Long And Prosper! 🖖🏻
Reply With Quote
  #18  
Old 07-02-2012, 02:29 PM
ArVeeNiner's Avatar
ArVeeNiner ArVeeNiner is offline
 
Join Date: Jun 2006
Location: San Jose, CA
Posts: 1,125
Default

Quote:
Originally Posted by RVbySDI View Post
I am going to say this is your culprit. When you mounted the magnetometer in the location you chose did you take into consideration the slider frame? The slider frame is steal so if it is slid open and within close proximity to the magnetometer it will affect the reading. I bet you will see a difference when you recalibrate with the slider closed.
I recall my roll bar being magnetized during the build. I degaussed it but I never checked the slider frame as I recall. My money is on the slider as well, Steve.

Thanks. I will perform a re-do soon.
__________________
Kelly Johnson
San Jose, CA
RV-9A

Pink slip issued: 5/7/12

First flight: 5/28/12, Memorial Day.

Phase I Complete: 8/18/12!

2020 donation: complete
Reply With Quote
  #19  
Old 07-03-2012, 09:32 PM
ArVeeNiner's Avatar
ArVeeNiner ArVeeNiner is offline
 
Join Date: Jun 2006
Location: San Jose, CA
Posts: 1,125
Default

Quote:
Originally Posted by DFlyer View Post
A couple of comments. First, is that with the compass mounted in a magnetically clean area, and calibrated, it should be very accurate. And second, do you have a sliding canopy? If so, then you need to calibrate with the canopy slid forward. The frame of the canopy will magnetically interfere with the compass calibration when it is slid back.

-Robert
Dynon Marketing
Robert

I think you're on to something here. I finally got out to the airport tonight and found out that the compass swings 30+ degrees between canopy open and closed!

Now I have to figure out how to keep my charts from blowing out when I fly with the canopy open!
__________________
Kelly Johnson
San Jose, CA
RV-9A

Pink slip issued: 5/7/12

First flight: 5/28/12, Memorial Day.

Phase I Complete: 8/18/12!

2020 donation: complete
Reply With Quote
  #20  
Old 07-09-2012, 07:54 PM
ArVeeNiner's Avatar
ArVeeNiner ArVeeNiner is offline
 
Join Date: Jun 2006
Location: San Jose, CA
Posts: 1,125
Default

Just a follow up. I calibrated yesterday with the canopy closed and the crazy winds aloft have gone away! Who knew this would have an effect on the weather!!

Thanks for the help everybody.
__________________
Kelly Johnson
San Jose, CA
RV-9A

Pink slip issued: 5/7/12

First flight: 5/28/12, Memorial Day.

Phase I Complete: 8/18/12!

2020 donation: complete
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 06:47 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.