Roll Rate Upgrade

I love the Decathlon. I really do. It makes any Cessna feel like its stuck in cement (and I love me some Cessna’s too.) Flying the other Decathlon at the contest was a revelation. That airplane had twice the roll rate of ours.

While I was at the contest I took some photos of the aileron (flippy doo thingys on the wings that make the airplane roll) deflection using my hand as a measurement. I wanted to compare the photos with the aileron deflection of 317SD back at PVD. The pictures tell the story. I was missing some deflection!




After a call to American Champion Aircraft we learned that the ailerons should deflect to 19 degrees positive and negative. When we measured ours we were under deflected by…a lot. I’ve basically been flying acro with an airplane that was set up not to roll like it should. No wonder all my rolls have been really difficult!

The culprit was found in the left aileron gap seal. There is a little bit of room between the leading edge of the aileron and the aileron bay of the wing. If air can pass through that area it creates a lot of drag and reduces performance. To combat that, ACA glues a strip of fabric from the aileron to the aileron bay, creating a seal of the gap (hence calling it a gap seal.) When our airplane was assembled back so many years ago the strip of fabric was glued in improperly, restricting the aileron from extending to its full 19 degrees. The simple fix was merely to undue the gap seal and reseat it at the appropriate point. Vwallah! Instant increase of roll rate.

I cant wait to try this out. I am expecting a few “wows” and ‘holy craps” on my next flight. Now I just need to wait for the glue to dry and the winds to stop blowing a gale. Probably wont be flying until next weekend.