Ring Race I level 9 uses a special challenge variant of the L-39 jet. Flaps are disabled on that challenge variant.
Retracts (Ch. 7) are active as Wildcard said, and they will affect your top speed once you get going. But even with retracts down and on low rates, I had no trouble getting up and through the first ring when I tried just now.
Don't be afraid to give it full elevator right off the ground even though you probably wouldn't crank on it that way at a real field. This is a challenge level, after all.
Beyond that, I'm not sure what's going on there. It's pretty difficult to say without seeing exactly that's happening on your screen and exactly what inputs you're providing. What kind of controller are you using? Is it properly calibrated? I wonder whether you're getting the full range of inputs. Yet you've made it through at least six levels to unlock level 9, so it seems like it can't be too far off...