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Weighing Procedures

sblakemore

I'm New Here
I am trying to find out the procedures for weighing by RV10. I did not build it, but I think we need to redo the weight and balance. The group of builders at my airport have a set of scales but they asked me what the "leveling" procedures are for the RV10. Can anyone tell me what that means or where I could find out?
 
Level in both horizontal planes using the bottom of the door sill. Not the fiberglass part surrounding the opening, but the flat aluminum sill inside the opening. I use sockets to get the level above the door opening / gutters for the lateral reading. You can lay a 2' level right on the sill for longitudinal reading. You will also need to measure the wheel axles distance from the CG datum. I don't recall where that is, but it is in the manual. Best to find the distance of the leading edge to the datum, then hang a plumb bob from LE and measure to axle center after aircraft is level.

Larry
 
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Manual

FAA has a free manual for downloading

Vans paperwork also has a chapter on it
 
Also, when doing W&B, you want to avoid side-loads on the scales; pure vertical weight complements of gravity is the goal, otherwise you'll pick up measurement errors.

A common trick is to put a folded plastic trash bag on the scale prior to wheeling the plane on. The friction is low enough between the layers of the bag to permit the tires to slide in/out/as needed to take out any side load. Folks also have oiled the bags to reduce friction further, but the general take away from the VAF brain trusts is that the bags are slippery enough out of the box.
 
Also, when doing W&B, you want to avoid side-loads on the scales; pure vertical weight complements of gravity is the goal, otherwise you'll pick up measurement errors.

Maybe I'm missing something, but:

Do side loads really matter when you're doing W/B measurements? All a side load is going to do is make it appear that the airplane is out of balance side to side. That has no impact on the fore/aft CG range or W/B, so I'm not sure it is a real world consideration.

Once you test fly the airplane, you're probably gonna have to trim it to achieve lateral balance anyway.
 
Side loads

Maybe I'm missing something, but:

Do side loads really matter when you're doing W/B measurements? All a side load is going to do is make it appear that the airplane is out of balance side to side. That has no impact on the fore/aft CG range or W/B, so I'm not sure it is a real world consideration.

Once you test fly the airplane, you're probably gonna have to trim it to achieve lateral balance anyway.

I think the thought is that the side loads will cause the scale to not be accurate. They aren?t talking about the plane leaning to one side, that would be compensated for leveling by lowering tire pressure. The side load can come from lifting the plane, then lowering it onto the scales. The gear flexes and can sideload the tire and scales. The slippery bag trick, or two greased metal plates, or making ramps and rolling the plane onto the scales can help settle the side loading..
 
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