Once more, N34KP weight and balance

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Richard Roller
Posts: 151
Joined: Mon May 22, 2017 11:14 am
Location: Olathe, Ks.

Once more, N34KP weight and balance

Post by Richard Roller »

Just for grins, because it’s very cold outside and I can’t work on the Piet, I’ve decided to investigate N34KP’s weight and balance if Ken had decided to slope the wing back instead of moving the engine forward. See the post I did on 11-10-2017 on the weight and balance problems of 34KP.
I’ve had to make an assumption of wing weight for this project. I’ve taken 34KP’s original weight and balance that I did 8-14-1999, this was done after finding the tail heaviness and before moving the engine. I’ve used the estimated wing weight from my project. I’ve been running a spread sheet of weights for my project so hopefully I won’t have a balance surprise when finished.

Datum: fwd. side of the lower firewall.

Original wt/bal dated 8-14-1999.

Item quantity wt. total wt. c.g. moments
Left main 1 328.00 328.00 16.75 5494.00
Rt. Main 1 313.00 313.00 16.75 5242.75
Tail wheel 1 17.00 17.00 158.5 2694.50

Total a/c wt.: 658.00 c.g.: 20.41 total moments: 13431.25

c.g. aft of leading edge: 12.91. % of wing chord: 21.52.

Original wt/bal dated 8-14-1999. Adding Ken and full fuel.

Item quantity wt. total wt. c.g. moments
Left main 1 328.00 328.00 16.75 5494.00
Rt. Main 1 313.00 313.00 16.75 5242.75
Tail wheel 1 17.00 17.00 158.50 2694.50
Fuel 12.5 6.00 75.00 29.98 2248.50
Pilot 1 236.00 236.00 60.32 14235.52

Total a/c wt.: 969.00 c.g.: 30.87 total moments: 29915.27

c.g. aft of leading edge: 23.37. % of wing chord: 38.95.

3.37” aft of the recommended aft c.g..



Moving the wing. I’m just showing moving the wing to balance the a/c with fuel and Ken as shown above.
Item quantity wt. total wt. c.g. moments
Left main 1 328.00 328.00 16.75 5494.00
Rt. Main 1 313.00 313.00 16.75 5242.75
Tail wheel 1 17.00 17.00 158.50 2694.50
Fuel 12.5 6.00 75.00 34.21 2565.75
Pilot 1 236.00 236.00 60.32 14235.52
Wing -1 114.00 -114.00 29.42 -3354.41
Wing 1 114.00 114.00 33.65 3836.10

Total a/c wt.: 969.00 c.g.: 31.70 total moments: 30714.21

c.g. aft of leading edge: 19.97. % of wing chord: 33.29.

So, tilting the wing back 4.23” would’ve moved the c.g. position on the wing to 19.97”, just forward of the aft edge. Of course moving the wing moved the fuel, in the case of 34KP (fuel in wing). That ended up making a difference of .4” more wing movement to allow for the fuel weight.

Once again the data got condensed when it post on the site. Not sure why as it's not that way when I submit the draft. Sorry.
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