Greetings,

I think I found the answer for why I couldn't get my DF to come back upwind to me a week or so ago. I was using full stick, and it just wouldn't bank more than maybe 10-20 degrees. Yaw worked fine, but nick and roll just wouldn't bank the DF enough to come back.

The answer is that TI doesn't always work the same from one cal to another (same day, same location, etc). Mike is the one who made me think about this again, because he mentioned that it seemed to calibrate better if you hold the arm button for 2-3 seconds, rather than just punching it quickly as I always do. He even said he thought he saw that in the instructions somewhere, but it sure isn't in mine, and it isn't in the on-line manuals at DFI.

This morning was a little windy, but without a cloud in the sky, so I did a test. I took the same DF (large frame BL mod) out in the yard, did my normal cal by punching the button quickly, and flew it a bit. This was all quite normal, with plenty of bank authority. Next, I tried it again, but this time holding the arm button for 3 seconds. It was like night and day! The DF was fighting me to stay level, exactly like it was doing the day I had to ditch downwind. I've always wondered why people complained that the DF wasn't responsive enough with TI enabled, but now I see why.

Just to confuse the issue, I went back out, and tried to repeat the test. This time, holding the arm button didn't make it behave any differently than just punching it quickly. Also, neither of these flights had the fierce TI leveling effect that I had on the earlier flight. Now I'm back to not being sure why it sometimes is more effective than others.

FWIW, in every test, I held the DF in the same location in the yard, and pointed the horizontal arms the same direction. Conditions didn't change significantly between test either. If I had to guess, I'd say that I've seen the excess TI effect about 5% of the time on average. Has anyone else noticed this?

Cheers,
Rusty