Weight & Balance Preparation

Today I prepared the airplane for weight & balance. The S-1S Inspection Procedures Manual includes a section on weight & balance; here's an extract:

Since this manual is for the stock Pitts with the bungee gear, I thought the main gear axle fuselage station depicted above was probably not right for my airplane. The manual said FS0 is defined as being 50" in front of the firewall. I therefore had to retrieve the longitudinal position of the wheel hub center relative to the firewall. I could tell it was definitely more aft than just 0.44" by simply looking at it.

I raised the tail so that the top longerons are level, then I used a plumb bob to precisely locate the firewall position on the floor:

Then I used the square to mark both wheel hub centers on the floor. After making two marks from the firewall and two marks from the wheel hubs, I rolled the airplane outside to draw two lines and measured 3.00" i.e. my wheels are more than 2.5" more aft than a stock Pitts. Good thing I checked!

Next step was to clean and install the remaining parts on the airplane: panels, cowl, wing root fairings and wheel pants. This is a lot of screwdriving work, but it paid off! For the first time in two years, all the parts were back together, it felt so good; it was like if she was alive again. Wx was nice outside so I rolled her out and took a few shots:

The only unhappy of this situation today was my wall of parts:

Next step is to weigh the airplane! My plan is to weigh the following configurations:

1. Zero fuel, no pilot
2. Zero fuel, pilot + parachute
3. Full fuel, no pilot
4. Full fuel, pilot + parachute

Doing the above will confirm the arms of the fuel tanks and pilot. More to come!