I wanted to confirm my weight and balance, since I bought this airplane last October from the second owner, and the only true weight and balance was done by the builder in 2008. Since then, weight and balance was done "on paper" i.e. adding and subtracting weight when hardware changes made - but I wanted true numbers. Since I was draining my tanks to calibrate them, I thought this would be a good time. I learned a couple of lessons.
- I drained the tanks completely because I was changing out my fuel drains
- After replacing the drains, I set the tanks to unusable fuel only
- I weighed the aircraft. The first time, I used some bathroom-type scales I got from the local EAA chapter. The measurements varied significantly between scales and iterations, so I took three data points, then rotated the scales between wheels, then took three more, and repeated until I had nine data points per wheel. I averaged these for what I figured would be some relatively accurate weights.
- I weighed the aircraft again. This time I was able to get some calibrated scales from an A&P friend. Very much easier to use, and I took two readings; they were within 2 lbs of each other in distribution between wheels, and gross weight was identical. Checking the numbers, they were also all within a half pound of the bathroom scale numbers I got yesterday, so while I wouldn't choose to do it that way, it actually works okay in a pinch.
- I have a 16 lb variation between the weight on my left and right main gear. I'm wondering how this compares to what others have seen. Any comments?
- My plane is 24 lbs heavier than my logbook said it was, but the CG is about an inch aft of what my logbook said. That's good - I have a forward CG due to CS prop and IO-360.
- I really hadn't looked at the "maximum nose wheel" weight restriction numbers. It's interesting - with pilot, passenger, and full fuel, I'm at 271 lbs on the nose wheel. If the passenger gets out, I'm at 346 lbs on the nose wheel with a maximum limit of 375 lbs, per Van's. Does anyone know if that weight limit is a static number, that takes into account normal landing forces? Or is it a "don't exceed 375 lbs, including when the nose touches down? I do my best to hold the nose off during landing, but with my forward CG, it's a challenge when I'm solo; thinking about adding some ballast to the rear baggage shelf to bring the CG toward the center when I'm solo, and would be interested to hear your thoughts.
I'm attaching a spreadsheet that I made to do all of these calculations. I usually do my W&B in ForeFlight, but this adds in the nose wheel weight calculation and checks both normal operations and aerobatic flight CGs, too. Enjoy. Note, I can't attach an Excel File, so here's the link to the file on my Google Drive
- I drained the tanks completely because I was changing out my fuel drains
- After replacing the drains, I set the tanks to unusable fuel only
- I weighed the aircraft. The first time, I used some bathroom-type scales I got from the local EAA chapter. The measurements varied significantly between scales and iterations, so I took three data points, then rotated the scales between wheels, then took three more, and repeated until I had nine data points per wheel. I averaged these for what I figured would be some relatively accurate weights.
- I weighed the aircraft again. This time I was able to get some calibrated scales from an A&P friend. Very much easier to use, and I took two readings; they were within 2 lbs of each other in distribution between wheels, and gross weight was identical. Checking the numbers, they were also all within a half pound of the bathroom scale numbers I got yesterday, so while I wouldn't choose to do it that way, it actually works okay in a pinch.
- I have a 16 lb variation between the weight on my left and right main gear. I'm wondering how this compares to what others have seen. Any comments?
- My plane is 24 lbs heavier than my logbook said it was, but the CG is about an inch aft of what my logbook said. That's good - I have a forward CG due to CS prop and IO-360.
- I really hadn't looked at the "maximum nose wheel" weight restriction numbers. It's interesting - with pilot, passenger, and full fuel, I'm at 271 lbs on the nose wheel. If the passenger gets out, I'm at 346 lbs on the nose wheel with a maximum limit of 375 lbs, per Van's. Does anyone know if that weight limit is a static number, that takes into account normal landing forces? Or is it a "don't exceed 375 lbs, including when the nose touches down? I do my best to hold the nose off during landing, but with my forward CG, it's a challenge when I'm solo; thinking about adding some ballast to the rear baggage shelf to bring the CG toward the center when I'm solo, and would be interested to hear your thoughts.
I'm attaching a spreadsheet that I made to do all of these calculations. I usually do my W&B in ForeFlight, but this adds in the nose wheel weight calculation and checks both normal operations and aerobatic flight CGs, too. Enjoy. Note, I can't attach an Excel File, so here's the link to the file on my Google Drive
