VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics


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 05-17-2020, 04:31 PM
lon@carolon.net lon@carolon.net is offline
 
Join Date: Aug 2015
Location: Santa Monica, California
Posts: 127
Default How to get access to Dynon ADAHRS

It looks as though my Dynon ADAHRS has failed. I've twice lost altitude and airspeed data, in flight. I've sent a Diagnostic Data zip file to Dynon Support (on May 3) and am waiting to hear back about what it says my problem is. In the meantime, I'm trying to figure out how to get access to my ADAHRS, if in fact mine needs to be replaced or repaired. I have a Van's RV-12, and my ADAHRS is in the tail, behind the storage area bulkhead. There are no access panels in the tail. I've seen posts on the Dynon Forum by owners who said they replaced their ADAHRS, but they didn't say how they did it; and they may not have had RV-12s. I didn't build my plane; I purchased it from the builder. But the tail-cone location of my ADAHRS is the location called for in the builder's plans. I hope I don't have to replace the ADAHRS. But if it turns out I do, I also hope someone can tell me how to get access to it without disassembling my plane.
__________________
Lon Sobel
Santa Monica, CA
RV-12, N58CV
VAF 2020 Dues Paid
Reply With Quote
  #2  
Old 05-17-2020, 04:40 PM
Hairball192 Hairball192 is offline
 
Join Date: Nov 2015
Location: Palo Alto
Posts: 24
Default

Hi Lon,

I'm still building and was just looking at that section of the plans and my plane. The ADAHRS is installed in the tailcone not far aft of the baggage bulkhead, which is removable. It's about as far back as the static ports so you should be able to reach it easily enough.

Regards,
Harry
Reply With Quote
  #3  
Old 05-17-2020, 04:44 PM
lon@carolon.net lon@carolon.net is offline
 
Join Date: Aug 2015
Location: Santa Monica, California
Posts: 127
Default

Thanks Harry.

Is the baggage bulkhead riveted in place, or is it fastened with easily-removed screws? My bulkhead is covered with fabric, so I can't see what holds it in place.
__________________
Lon Sobel
Santa Monica, CA
RV-12, N58CV
VAF 2020 Dues Paid
Reply With Quote
  #4  
Old 05-17-2020, 04:46 PM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 1,896
Default

Hopefully, you have the easily removable rear panel in the baggage compartment identifiable by separate panel that ramains fixed right behind the fuel tank. Early RV-12's had a one-piece rear bulkhead that required removal of the fuel tank to access panel fasteners. Needless to say, that was a PITA. Van's redesigned and added the stationary panel behind the fuel tank and most everyone has made the conversion. Hopefully, you're in that group. That said, you remove the rear bulkhead and your ADAHRS should be accessible.
__________________
-
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 564

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
Reply With Quote
  #5  
Old 05-17-2020, 04:58 PM
lon@carolon.net lon@carolon.net is offline
 
Join Date: Aug 2015
Location: Santa Monica, California
Posts: 127
Default

Hi Jim,

My plane is a 2018 model, so I have reason to hope that my bulkhead is the easily removable one. The builder's plans show the bulkhead to be at least three separate panels: left, right and top.

Thanks, Lon
__________________
Lon Sobel
Santa Monica, CA
RV-12, N58CV
VAF 2020 Dues Paid
Reply With Quote
  #6  
Old 05-17-2020, 06:27 PM
pilotyoung pilotyoung is offline
 
Join Date: Jan 2018
Location: Birmingham, AL
Posts: 182
Default How to get access to Dynon ADAHRS

Lon,

With yours being so new, I feel sure it will be a two piece bulkhead. If their is a cloth or leather cover over it, once you remove it, there will be screws to remove and take it out. The ADAHRS is easily reachable once you remove the bulkhead.
__________________
John D. Young, RV-12 Owner
Serial Number 120022, N6812Y
Bought it as a flying airplane in Feb. 2018
Just passed 240 hours flight time in RV-12, and 10,000 hours mostly in corporate jets. I am a CFI; CFII; MEI; and a advancd Ground Instructor, CFIG; and hoping to be able to help new RV-12 owners by doing some transition training for new builders and owners in RV-12's.
Reply With Quote
  #7  
Old 05-17-2020, 06:38 PM
Tony_T's Avatar
Tony_T Tony_T is offline
 
Join Date: Dec 2008
Location: Lacey, WA
Posts: 1,332
Default

You will have to pull off the fabric upholstery from the baggage bulkhead. It is held on by strips of Velcro. There may also be a couple of screws at the bottom edge. You have to bend the stiff upholstery panel and work at it carefully to get it off. Then there will be a number of phillips head screws holding on the panel. Be careful removing those and don't drop any behind the fuel tank. There are stainless and non-magnetic and you can't reach in there with a mechanic's magnet to retrieve them. I spent more time once trying to get back a dropped screw than taking everything apart to get access to the tail-cone!
The ADAHARS is up on the top of the tail-cone and pretty easy to get to. You do have to squeeze through the opening if the fuel tank is in place, and you will have to lie on your back to work. There are control cables running back to the tail. You could probably arrange 2 or 3 moving blankets to pad yourself and keep pressure off the cables. I made a little floor panel out of scrap because I have been back there a few times now and wanted a little more comfort. It rests on the first bulkhead back and it has slots to keep my weight off the cables.


The ADAHRS will have one electric D-sub and 3 tubing connections. Mark the tubing so as not to mix them up. The ADAHRS is held on to its mounting bracket by four small non-magnetic screws, nuts, washers. Be careful not to drop these small parts as they will be hard to find.

Try to figure out what tools you will need before going in. It's a real pain to get back there and need something. If I remember correctly you need a short #2 phillips and a small metric combination wrench, forgot the size, take a couple of your smallest. Have a helper on the outside.

I have put a padded sawhorse under the tail tie-down ring so if the plane wants to tip back from my being in tail-cone it won't go all the way to the hangar floor. I weigh about 190, it has never dropped back.

I hope you don't have to remove your ADAHRS but this may help if you do.
__________________
Tony
E-LSA RV-12 ULS
Reply With Quote
  #8  
Old 05-17-2020, 06:46 PM
Bob Y Bob Y is offline
 
Join Date: Jul 2017
Location: Piedmont, SC
Posts: 141
Default

And make sure the tools you use to remove the ADAHRS are non magnetized and keep it away from magnetic fields after removal.
__________________
Bob Y - builder 12iS
N569TT first flight 2/9/2020
Reply With Quote
  #9  
Old 05-17-2020, 06:47 PM
lon@carolon.net lon@carolon.net is offline
 
Join Date: Aug 2015
Location: Santa Monica, California
Posts: 127
Default

John and Tony,

Thank you! And Tony, thanks especially for the photos and the alerts about the screws being non-magnetic. I'm waiting, more or less patiently, to hear from Dynon. And I'm hoping my problem is more easily fixed than removing the ADAHRS would be. I've lost altitude and airspeed data twice, but I've also enjoyed flights where everything worked perfectly. And when the data disappeared, I did not get an "ADAHRS Failed" message or a red X through the display. All that happened was the airspeed dropped to 0 and the altitude shot up to 50,500!
__________________
Lon Sobel
Santa Monica, CA
RV-12, N58CV
VAF 2020 Dues Paid
Reply With Quote
  #10  
Old 05-17-2020, 08:03 PM
Mich48041 Mich48041 is offline
 
Join Date: Apr 2008
Location: Riley TWP MI
Posts: 3,011
Default

The majority of electrical problems are caused by bad connections rather than
equipment failure. The fact that the problem is intermittent also points to a bad
connection. I suggest taking the connectors apart and checking for broken
wires or bad crimps or pins not seated properly.
__________________
Joe Gores
RV-12 Flying
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 01:09 PM.


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.