DonMuncy

Bravoman, Can you compare that unit to the video of my tug in action. I wonder how mine compares. No need to comment on my steering abilities. Tow_video_4.mp4

Only in aviation will you find "0.5 AMUs", "only", and "isn't that bad", all in the same sentence.

People buy chocks? A couple of 10 inch long 2x4s work fine. If you want to be fancy, a couple of eye screws and 2 of feet of rope. Sheesh. How are we ever going to grow the ranks of CBs. If you have/get a hangar, one of the first things you will want to do is paint stripes for the wheels.

Like I said, "unless you are a mathematical genius...." Yes, in a sense I understand, but it is still difficult. And yes, it would be a little easier to calculate if the datum was in front of the plane, rather than somewhere near the panel like Mooney does it.

I would add that recalculating all your W&Bs is not an exercise for the weak at heart. The weights are easy. The moments and CGs are entirely different. The worse part is that they are not intuitive, at least for me. Removing an item generally results in a minus to the moment, but if you change a prop, you will wind up doing a minus for the removal, but it is at a negative station, so the two minuses turn into a positive. How does anyone who is not a mathematical genius wrap their head around that. Living with some minor errors starts looking pretty nice.

Prepare yourself. They have a flat rate (not cheap) to do any repair.

Yes, Anthony, I have had a bunch of education, but never took Statics. I managed to wade through all my W&B calculations, for a net useful load gain of 2 pounds due to errors, and less than 1/2 inch in CG. Actually, except for rounding errors, the only change was where my avionics shop managed to overlook one sheet back in '04, which then tainted all the numbers up until now. So, mainly an exercise in futility, except for the satisfaction of knowing it is right, and I now know how to do the calculations.

Has someone created an app to calculate W&B changes. I am doing mine by hand and it is driving me crazy.

I answered my own question. When I started redoing the calculations in my records, I figured out that is exactly how it is done. The way that RLCarter says. Calculate the Moment of the new item from the weight and arm. Add the new item Moment to the old total Moment (to derive the new total Moment) Then multiply that Moment by 1000 and divide the result by the new total weight to get the new total arm. Every A&P and avionics tech knows how to do this. Duh. I guess I'm the only one that had not gone through that process before.

First, how did you figure that out? Second, any idea why they would do it that way. Do you surmise they weigh the plane and use that to locate the center of gravity. I'm not sure I understand how that works. (But the fact I don't understand it is not surprising)

Thanks for the info Skip. Incidentally, one of the tubes at my cowl flap drips a few drops of what appears to be fuel sometimes at shutdown. I assumed it was from the sniffle valve, but I have no idea where it comes from.

I have read on MS several times that nylon ty raps would cut into aluminum tubes. I'm not contending this is untrue, but has anyone seen a ty rap actually do that, or make a discernable groove in the aluminum.

I was reading the other post on weight and balance, and just for fun, decided to check mine. Interestingly, the very first entry (from the factory) seems to have an error. The empty weight is shown to be 1930 at an arm of +43.6, but the moment/1000 is listed at 84.08. Unless my calculator has malfunctioned, the moment should be 84.148, or rounding like they did, 84.15. I recognize this is a miniscule difference, and a little unlikely to cause me to fall out of the sky. But just to play the super accuracy game, do you think they wrote down the arm incorrectly, or did the calculation a little off. What do all the other K model owner's W&B say? Mine is an 82 model, serial number 25-0686.

Got any better pictures? Does it lift the nose gear? If so, what does the lifting? Your leverage on the handle? I'm always looking for ways to perfect my design.

I think I might be able to understand that. I always check for airspeed early in the roll, but I don't know how long it would take me realize it had not come alive and I had to do something.