Friday, January 07, 2011

Four busy flights

Today at Crystalaire it was cold and calm, with only high clouds, so we were able to do some high flights for further preparation for my Commercial practical test. Most of it went well, except for some areas I'll delve into below. Four flights, one of them the highest tow I've ever taken so we would have time for a lot of air work. We covered many things, including: all tow signals, boxing the wake (my first time in a Grob 103), steep turns (nailed it!), stalls and detection of incipient stalls (straight, turning, with and without spoilers), spin awareness (we couldn't really get it to spin), hard slips (harder to control in the Grob than in Blaniks), slack line, slack line in turns, precision landings.

Slack line in turns gave me lots of trouble. This instructor teaches yet another method. When I first learned to fly, slack removal was accomplished by yawing the glider away from the towplane and then straightening it out just as the slack comes out. I learned to do that really well and smoothly. When I first trained for Commercial about two years ago, the instructor said current practice had switched to a "do nothing" method. Basically you realign the glider with the towplane and let the slack come out gradually as the glider slows down. This time around, the approach is a "climb and dive" method: align the glider and climb parallel to the towplane to slow down, then dive slightly and come back behind the towplane just as the slack comes out and the glider's speed again matches the plane's speed. I took several times to get what he was trying to show, and finally got some really good recoveries on the right side (left turns). On the left side, I got way out of line - I think I was diving and realigning way too early, causing even more slack. One time it came out so abruptly that I broke the weak link. Another time the slack got so big that we released from tow. This was really weird and difficult - not natural at all. Before today I'd had 275 flights, some with strong turbulence on tow, and I've never even come close to breaking a rope or getting such a huge loop of slack line. We debriefed about it later, and I'll study the book and we'll try it some more next time. I will learn to do it this way, but I want to think about it some before I try to teach it. This really seems much more complicated than it needs to be. I thought about practicing on Condor, but he says Condor doesn't allow slack. If any readers have comments on this topic, I'd like to hear them.

Precision landing is giving me some trouble, probably because I've not tried to do many of them in the Grob. Only about 20% of my flights have been in the Grob, and many of the landings were on long runways as opposed to the short-field landings we practiced so much in the Blaniks. We realized I was not using an aiming point but rather I was aiming for the touchdown point and not doing a sharp roundout, so I worked on that. (On the plus side, my speed control was much better than last time!) Also, I need to do a paradigm shift: initially I was taught to not touch the spoilers hardly at all after roundout: adding them can cause a hard landing, and closing them can cause ballooning. But I need to break out of that model and gently adjust spoilers to effect the touchdown exactly where I want it. I think that's harder in the Grob because the spoiler control is stiff and hard to finesse. CFI's recommendation is to brace my arm against the side, and use wrist motion rather than arm muscle to move it a tiny amount. So that's on the agenda for my next session.

1 comment:

PMSC Member said...

I don't think there's any single method of recovering from a slack rope. The objective is fairly clear: to wind up with the rope extended and speeds matched. But the means of getting there involve so many variables that the only effective teacher is experience. Sort of like thermalling.