N180PB weight and balance

[Collin Campbell]

I finally got around to weighing my Patrol. After measuring carefully (several times) and doing all the math, I feel that I have come up with an "official" weight and balance for N180PB. I am attaching a copy, hope it comes through OK. One thing for sure is to check the arms for your particular aircraft--I have found some differences from what others have come up with. Most notable was the tailwheel arm. Mine was 200" while I have seen 205, 203, etc. Don't know why this is...The other difference was the fuel tank arm. This one was easy to obtain, just got out my master wing form block, and then laid the fuel tank form block on top in it's proper location. Measured from the leading edge (datum) to the center of the fuel tank form block. 24.5"...Don't know how others have come with 22"...but that is what Bob used in his calculations. Maybe I'm missing something here, I don't know. Anyway, looks like I have a forward enough E.W. CG. I have the 0-360 engine with Sensenich metal prop, full electrics, skylite, ALL fairings, strut cuffs, etc, 8:00-6 tires, fabric interior, 3" seat cushions, 2" backs. I have a simple panel, AS, ROC, ALT, TC, with Grand Rapids engine monitor, Radio and Garmin Aera 500 GPS. W@B 180PB.doc Collin Campbell N180PB Bolivar, MO

[X'N]

Got any pictures of it? Would love to see some!

[Collin Campbell]

Dan, I'll get some pictures soon. Don't have any complete ones right now...

Collin

[X'N]

Cool.

How long have you been working on your patrol? Complete scratch build?

[Collin Campbell]

Dan,

Been working on it eight years. Yes, completely scratch built. The 4-place took me 6...getin old I guess.

Collin

[Enewton57]

The file was there so you did something right Colin.

As to the fuel tank, I didn't measure to the center of the tank because I was taking into account that the tank gets smaller toward the back than at the front or in the middle. I figure there is more fuel toward the middle 1/3rd and front 1/3rd that there is at the aft 1/3rd, so I went with Bob's figure of 22"

[Collin Campbell]

Eric, good point and I considered that when I measured my tanks. The tank is taller at the front, but I considered that I never fill the tanks all the way up to the filler necks. Leave a little room for expansion when the fuel gets warm, and less chance of loosing fuel through the vents on the ground or in flight. So if I don't ever fill them completely, the taller area in the front is just "air" space. I can see how this can be veiwed differently though...just sayin..

Collin, Bearhawk N370CC, Patrol N180PB

[Collin Campbell]

Also, even considering that the tank is taller in front (.75" or so) even with full tanks this only moves the overall cg of the tank forward roughly half an inch. Do a "mini" weight and balance on just the tank itself. Start with fuel to the level of the aft (short) end of the tank. Measure the arm from front of tank (datum). Then calculate the fuel that would be added to the top portion of the tank. Come up with a added weight and arm. Interesting and something to do if you get snowed in and get bored... I also considered that in level flight the tank and wing 2 deg. angle of incidence--less than 1/8" or so...not a huge factor I don't think. As they say, "your mileage may vary" or something like that...It's fun trying to figure things out..

Collin