Saturday I had an interesting flying experience taking off on runway 29 at Columbia. I might well have crashed if it weren't for the instructor with me. Great lesson.
29 is a grass runway, a rarity in California. I'd trained on soft field technique for my license but I'd never done it for real. The trick is to get the wheels off the ground as fast as you can so you can accelerate better. Because of ground effect you actually lift off before you're going the 55kts or so you need to properly fly, so it's important to push the nose back down towards the ground so that you stay level in ground effect until you accelerate to flying speed.
But 29 isn't just a soft runway, it's short. 2600' but with a 1% upslope and a 40' hill just 1200' past the runway end and another hill with trees on it just past that. I've trained on short field technique and thought I was pretty good at it. It's easy enough; you rotate precisely at 52kts, climb at 61kts, and know the math ahead of time for how much distance you need to clear your obstacle.
That's all the theory. In practice what happened was we rolled slowly down the runway and the wheels come off the ground just at our abort point. Great, we're airborne! Then I looked up and saw the hill coming at me and freaked out and did precisely the wrong thing, pulling back to try to climb fast. Only we were going so slow that the moment we got out of ground effect the plane would have come right back down again, crashing us in to the hill.
Fortunately my instructor has enough experience to anticipate the mistake I was going to make. He immediately took over and did the right thing, the scary thing, pointing the plane's nose down into the hill for a few seconds until we were fast enough to pitch up and climb. He tells me we cleared the hill with plenty of room to spare, I didn't see a thing because my eyes were shut tight. (OK, not really, we were just pitched high enough I couldn't see the hill in front of us. Next time I'll look out the side.)
I'm exaggerating the danger for effect, I'm sure my instructor knew all along we would be fine. But I didn't know that and I wouldn't have been fine by myself. I'm well enough trained now that the ordinary flights I do are pretty boring; it's easy to get complacent and sloppy. Great lesson to see the importance of proper technique. It's also useful to learn the limits of your skills. I don't plan to do a soft + short field takeoff on my own anytime soon.