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RV6A Panel Arm?

dvalle

Well Known Member
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
 
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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
 
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:)
 
Confused by the ques ...

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?
 
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

izB9I7.jpg


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.
 
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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
 
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.
 
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