Saturday, April 11, 2009

Lift Under Overcast

The day did not live up to the forecast. The day after a minor cold front went through... cold temperatures aloft... forecast for a high in the low 60's but with only 35-45% cloud cover. Depending on which sounding you believe, the lift could go to 7,000' or 9,000' MSL. Unfortunately it was 100% cloud cover until about noon. It cleared over the valley for maybe an hour, but was still 85% cloudy. It was fairly warm in the areas where the sun hit (well, it helped that I was wearing a black coat).

I was planning to just do a flight to practice some of the maneuvers for my Commercial practical test. I needed to work on some slips, especially switching from one side to the other. And I wanted to work on maintaining constant speed when using spoilers. Both of those use up altitude, so I was hoping for some sustaining lift. I found some weak lift up to 1-2 knots, generally just a few hundred feet below the darkest clouds. (Of course, I stayed 500 feet below them.) Having my clip-on audio vario was helpful. I never gained more than 200-300 feet at a time, but it was enough to extend my flight to 31 minutes from a 3000' tow, even with me doing some slips and spoiler tests. (You need to nose down just a bit when deploying the spoilers in the Blanik, or you lose a little airspeed. That's something my instructor wanted me to smooth out.) I think the valley floor was still radiating the heat that it absorbed during that hour or so of noontime sun.

One of the things I needed to practice was flying the whole pattern and landing with no drag devices. I made sure to get to the Initial Point with plenty of altitude. Then I hit a big distraction as I was trying to get lined up for my downwind leg. I found that I could not lock the retractable landing gear in the down position, because my water bottle in my cargo-pants pocket was in the way. I fooled around with it and had to actually move the stick way left to get my leg out of the way, and that messed up my speed and direction and attitude a bit.

The wind was from the right, but not directly, which meant that a right-wing-down slip would be used on the downwind and base legs. That went really well. Since I would need to reverse my slip on the final leg, I got out of the slip, did a coordinated turn to final, and then left-wing slipped on final. When I decided to come out of that one, I found that my speed was WAY up (the airspeed indicator is incorrect during slips), probably over 65 knots (should have been 55). I was down to a hundred feet or so, so I reduced my speed, used spoilers and landed right in the box. I think I bounced it a little, but stopped right in the first box as required for the Commercial test.

Other than the speed control on short final, not a bad little flight on a very gray day.

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