RE: Great Planes Shoestring
I have just about had it with that TT91. I fought with it through over five tanks of fuel, and the best I can do is too rich at idle with a full tank and at the same time too lean near empty. The lowest reliable idle I seem to be able to manage is about 2600. I felt this was high, but I thought I could handle it.
So this afternoon, I took it out to the field and took the plunge. Had a bad time with my Cub and a malfunctioning throttle, and after two hours gave up on that and decided to try the Shoestring. Taxiing turns out to be a real bear; the way it balances over the gear, anything below half throttle invites a noseover. After nosing it once and stalling it out two other times, I finally figured "to heck with it", and once I had it rolling I just throttled up and pulled back, and off it went.
Not sure where I went wrong with the elevator, but even at full down trim it was still climbing at half throttle. Flew for a while that way, did some loops and some rolls; man is that thing fast! Needs rudder in the turns. And now I know why the guy didn't put the markings on the bottom of the wing - it's *real* easy to lose orientation when the top and the bottom are identical.
About half way through, I decide to try some approaches. This is where the fun starts. I throttle back, come around on base at my usual altitude, cross the threshold a little high and try to chop the throttle, and find to my dismay that it was chopped! It flies by me at idle setting about 10 feet off the deck, not showing any tendancy to want to slow down before it reaches the end of the field. I only need one click of throttle to continue flying at a comfortable speed; at this point I realize I'm in trouble, the thing isn't going to stop. I try several approaches, each one longer and lower than the last, which were equally as unsuccessful. Then, I try just flying it onto the runway, hoping the grass will slow it enough to stop it, buy after a 150-175 foot rollout, it's clear each time it would hit the high weeds at 30mph, so I gun it at the last minute and go around.
I get desparate and try reprogramming the end point on my throttle channel lower, but it still doesn't seem to be slowing any more. On the fifth attempt at landing it this way, I pull up again and turn to go around, and just as I get downwind the engine sputters and quits (on, did I forget to tell you my timer went off on attempt #4?). NOW the silly thing wants to come down, but I'm 100 feet from the runway edge and 25 feet off the ground, turning toward a quartering wind. Needless to say, I didn't make it back. I came down fairly hard in the high weeds, but flat and almost level.
Thanks to all the recommendations to reinforce the gear mount from here on RCU, I had glassed the mount area with 6oz. cloth. What I found after trudging out through the weeds is that I had slightly bent the left gear, and that's it! Thanks guys! Sorry, there were no pictures - my photographer (my daughter) was out on a school project with her mom today.
I tried this flight with a MA 14x8; I guess next I'll try a 15x6. I'll also spend yet another evening battling with the mixture screws. I figure I gotta get at lest 2200 reliably or I'll be dead sticking it again. But overall I was pleased with the performance; it'll be a blast flying this plane when I know I can get it back on the ground!
John, I'll try to post pictures of the cockpit mount tomorrow night.