VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #1  
Old 08-26-2017, 02:45 PM
dvalle dvalle is offline
 
Join Date: Aug 2011
Location: SE Michigan
Posts: 100
Default RV6A Panel Arm?

This is very strange for a person that's been flying certified aircraft for MANY years. How do you do a weight and balance without an arm, weigh the aircraft each time?? Thanks

Last edited by dvalle : 08-27-2017 at 08:12 PM.
Reply With Quote
  #2  
Old 08-28-2017, 07:24 AM
ChiefPilot's Avatar
ChiefPilot ChiefPilot is offline
 
Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,423
Default

Quote:
Originally Posted by dvalle View Post
This is very strange for a person that's been flying certified aircraft for MANY years. How do you do a weight and balance without an arm, weigh the aircraft each time?? Thanks
Not sure it's possible - without the distance to the datum, you can only find the new weight and not the new CG.

In answer to the thread title, my panel is at 72" from datum - however - I have a custom fiberglass panel and not the stock aluminum one. This should get you close though.

Cheers!
Brad
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
Reply With Quote
  #3  
Old 08-28-2017, 11:02 AM
Jesse's Avatar
Jesse Jesse is offline
 
Join Date: May 2005
Location: X35 - Ocala, FL
Posts: 3,163
Default

Should be just about the same as the fuel unless it's a deep instrument.
__________________
Jesse Saint (Saint Aviation, Inc. - VAF Advertiser)
352-427-0285
jesse@saintaviation.com
RV Hotel (hangar, room, car) at X35 in north FL

Commercial ASEL/S A&P/IA EAA Technical Counselor

Dynamic Prop Balancing, Prebuy Inspections, Condition Inspections, Repairs and Mods, Injector Tuning, Airframe, Engine, Panel Upgrades, Ferrying, etc.
Reply With Quote
  #4  
Old 08-28-2017, 10:03 PM
dvalle dvalle is offline
 
Join Date: Aug 2011
Location: SE Michigan
Posts: 100
Default Panel Arm

Yes, the panel arm should be close for me. Regarding instruments and gauges, the arm changes for them unless they are VERY short:-)
Reply With Quote
  #5  
Old 08-29-2017, 12:08 PM
RViter RViter is offline
 
Join Date: Jun 2009
Location: Mesa, AZ
Posts: 170
Default Confused by the ques ...

Quote:
Originally Posted by dvalle View Post
This is very strange for a person that's been flying certified aircraft for MANY years. How do you do a weight and balance without an arm, weigh the aircraft each time?? Thanks
Is it a -6 or -6A?
Pulled out my earlier paperwork but the datum is 60 inches forward of the Wing LE, which makes the datum an imaginary point a bit forward of the spinner tip (to avoid the potential of a negative arm).
The W&B for a -6A, (Section 14 of construction manual) "DATUM - 60 inches forward of wing leading edge. (L.E.)" You can measure forward or aft of the LE to determine a/c re-configurations over time, adding/subtracting from the 60" length to determine the arm or each change.

Baggage is 117"
Fuel is 70"
Pilot/Pass is 87.4"

You need the 'empty wt' or re-weigh in the proper configuration to calculate it again. (Flight level attitude, etc). Then you can program in the ARMs and Station weights for whatever W&B app you like. (ForeFlight has a good one).

Is that what your asking?
__________________
gary
RV-6A QB Tip-Up, 1st Flight 3/18/17
O-360-J2A (modified & F/I), Sensenich FP (cruise)
VP-X Sport, Dynon SkyView, VFR day
(FFZ) Mesa, AZ - N234GB -
www.mykitlog.com/garyc
Reply With Quote
  #6  
Old 08-29-2017, 09:44 PM
az_gila's Avatar
az_gila az_gila is online now
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,812
Thumbs up In a picture

I did a little taping and measuring today for my own reference since the plans do not directly give a RV-6x wing LE location on the fuselage drawings.

This should help - NOTE - RV-6x ONLY



The panel face where it meets the sloping cockpit rail is 11.4 inches aft of the datum line. Note the panel slopes forward so make adjustments as needed.

An easier point to measure from for W&B additions/subtractions may be the forward metal edge of the fuselage sides at the cowling. It is 12 inches forward of the datum.

PS Hope the new picture posting site works... If you have a -6 copy it for reference.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ

Last edited by az_gila : 08-29-2017 at 10:13 PM.
Reply With Quote
  #7  
Old 08-29-2017, 10:21 PM
dvalle dvalle is offline
 
Join Date: Aug 2011
Location: SE Michigan
Posts: 100
Default Arm for an RV6A

Thanks for the replies. So it looks like 11.6"? 72"? Help:-)? I'm thinking the first reply then is 12". Agree?

Thanks
Reply With Quote
  #8  
Old 08-29-2017, 10:47 PM
az_gila's Avatar
az_gila az_gila is online now
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,812
Thumbs up What Vans Aircraft says

No, the datum is an imaginary point 60 inches ahead of the wing leading edge.

The LE is a reference point at 60 inches and you can work aft and forward of that in measurements.

In this case Vans has set the measuring points and the CG limits

http://vansaircraft.com/pdf/RV6Awb.pdf

http://vansaircraft.com/pdf/RV6wb.pdf

Use those numbers and measure everything with the longeron from the tail to the cockpit rail level per the documents.

At the point I mention/show of the panel and the cockpit rail, the moment arm would be 60 + 11.4 = 71.4 inches

As an example - If a gyro instrument you are adding has it's CG is 3 inches behind the panel (a forward direction), then it's moment arm would be 71.4 - 3 = 68.4 inches.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ

Last edited by az_gila : 08-29-2017 at 10:53 PM.
Reply With Quote
  #9  
Old 08-30-2017, 08:40 PM
dvalle dvalle is offline
 
Join Date: Aug 2011
Location: SE Michigan
Posts: 100
Default Panel Arm

Got it, thanks
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 09:03 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.