Mel: Wt. & Balance-- Most Aft problem

[yankee-flyer]

When I compute the most aft weight and balance with my weight (165 pounds) it comes out just outside (to the rear) of the envelope in the POH. Do I submit this actual number to the FAA or do I use the "Standard" piolt weight of 190 pounds which is just inside the envelope?

Thanks

Wayne 120241

 

[Tony_T]

W&B

Hi Wayne,
I'm not Mel, but your numbers don't sound right. With 50 pounds of baggage and full fuel my spreadsheet for my aircraft says I would have to be a 100 lb pilot to just go aft of the CG limit. I should say that my nose wheel weight is 150 pounds which, I think, is more than others have reported.

Left main measurement is 23.125
Rignt main is 23.25
Nose wheel is 40.375 (a little more than yours probably because of the extra weight on the nose wheel which I can't explain).

In any case, I would think that a 165 pound pilot would be well inside the envelope by design.

Tony

 

[yankee-flyer]

Thanks Tony

I'll run the numbers again but it's good to see someone else with slightly different arms for the mains. I used 23.2 for both in the calculations.

 

[Jetguy]

Nose Weight

My nose wheel wt was 147lbs. What kind of scales did you use and was the cowl and prop on as well as full oil and full coolant? Were you weighting in a no wind situation?

John
RV12 N1212K

 

[yankee-flyer]

Electronic scales

We used a set of electronic scales that are used for weighing race cars and airplanes. Oil and coolant were in prop and spinner were on. Only thing I can think of is that the purge hadn't been done and there might have not been much oil in the gearbox. We were inside the hangar.

Thanks Wayne

 

[rvbuilder2002]

The gear box only holds about 1 measuring cup of of oil so I don't think that could account for the discrepancy.

 

[Geico266]

Dump question, but did you have the canopy closed? My first weight was with the canopy open. Needless to say those numbers were scarey!

With a pilot weight of 165 I think you are going to show a descrepency in extreme CG limits. I have not looked at my W&B for a while, but I remember it being at the limit when calculating most aft and most forward. Use the FAA standard pilot weight (170 pounds I think) for the calculations. Certainly the plane will fly fine with you in it, just make a few stops at Burger King ( and jumbo size it) before each flight. You'll be in CG before you know it!