Is it safe to use the sample arms in the manual?
... Is it safe to use the sample arms in the manual?...
FYI - Nobody ever needs to raise the tailwheel while trying to balance it on a scale at the same time.
1. Weigh the whole aircraft in three-point attitude.
2. Raise the tailwheel off the rear scale (just pick it up and put it flat in your hands) until the fuselage reads level.
3. Have someone read the two main gear again.
4. Tail weight is total from (1) minus total from (3).
Math is your friend.
You're mixing two different things... First, the math *has* to work out that way, it's gravity and trigonometry, the laws of which are pretty much irrefutable.it has been my experience that the math does not always work out that way due to the variation in the scales.
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I generally weigh the airplane 3 times in the 3 point attitude, and 3 times level before I settle on the final numbers.
Sounds like I need to borrow the jack
You're mixing two different things... First, the math *has* to work out that way, it's gravity and trigonometry, the laws of which are pretty much irrefutable.
Second, the issue with scale variation is an issue with scale calibration. If they don't all match, rotating them around just moves the error around and you will never get a reading more accurate than the average error.
it has been my experience that the math does not always work out that way due to the variation in the scales. If you do try it that way, I'd recommend a series of 3 weighings, rotating the main gear pads each time and if close, do the average. That should flush out any outlier readings.
I generally weigh the airplane 3 times in the 3 point attitude, and 3 times level before I settle on the final numbers.
And yes, you can measure arms before or after.
You're mixing two different things... First, the math *has* to work out that way, it's gravity and trigonometry, the laws of which are pretty much irrefutable.
Second, the issue with scale variation is an issue with scale calibration. If they don't all match, rotating them around just moves the error around and you will never get a reading more accurate than the average error.
It is if you don't really care how precise the C.G. calculation is.... the RV-8 probably has the highest possibility of variation because of how the main gear legs attach.
Why not just do it now? The airplane doesn't know whether it is up on scales or not. As long as you position the airplane level as it was while on the scales you will get the proper result. It is actually easier to do with the airplane not on scale pads.
Yes, exactly... But that's okay. All you care about is the weight on the wheels when the aircraft is in it's level configuration.Just considering the accuracy of this method. Wouldn't the weight forward of the pivot point change the weight on the tail Wheel? Meaning as the tail comes up mass forward of the gear (pivot point) increases, countering the weight on the tail?