Thursday, August 28, 2014

A few stats from my logbook

I just completed selling an old Blanik L13 for my club. This particular ship had been crashed, and totaled by the insurance company, but was really not damaged very much. As I wrote the final email to the buyer I mentioned that I would miss the ship, having made 75 flights in it.

That made me wonder just how many flights I have made in which ships. So I ran some stats from my electronic logbook. My flights turned out to be surprisingly evenly distributed. Check this out:

Blanik L13 #178
Blanik L13 #275
Grob 10373
Blanik L13 #317
Other Grob 103's5

Sunday, August 17, 2014

First flight in Krosno

Those of us from OCSA who have become members of Cypress Soaring (CSI) have to get instructor signoffs to fly each category of Cypress' gliders. The starting point is the Krosno trainer. I'd seen the Krosno many times when both clubs operated at Hemet, but I had never even taken a close look at it until this weekend. Between my schedule and theirs, this Saturday was the first time I was able to book the first of two checkout flights. It was about 102F for much of the afternoon at Lake Elsinore.

I had of course read the flight manual, so I was familiar with most of the features of the glider. OCSA used Blanik L-13's for trainers, so here I'll list a few similarities and differences between the two.
  • Both are all-metal ships, with fabric control surfaces.
  • Both have forward-swept wings. As I understand it, that places the center of lift very near the center of gravity, so when the instructor gets out for the student's first solo, the flight characteristics hardly change at all.
  • The Krosno has a T-tail. Just ask my forehead!
  • The Krosno only has instruments in the front cockpit. The instructor has to look around the student's head to see them.
  • It has a main wheel, a non-castering tailwheel, and a nose skid. I'd never flown with a nose skid before.
  • Its airbrakes are retracted automatically by springs - you have to hold them open.
  • Its rudder is medium-sized, which takes more effort.
  • Its wheel brake is activated by a handle on a cable, not a lever. It's not very effective, so the nose skid is the main brake.
  • This unit has wingtip wheels, so it can do wing-down takeoffs easily (which we did).
  • It has bolt-in ballast on the front cockpit floor.
  • It has a handle on the tail, which makes ground handling pretty easy.
  • It has NO pockets or storage in the front cockpit. Fortunately my little water bottle fits in my cargo-shorts pocket, and my radio clips onto the harness pretty well, though it would not be very secure in turbulence.
The flight went fine. It seemed to me that the ship wanted to yaw to one side, and took a bit of both aileron and rudder to get the yaw string straight. (One of our Blaniks used to fly that way - we called it "right-wing-heavy" and eventually installed a little trim tab to even it out.) Or maybe there was a crosswind on tow that was causing it, but I don't think the wind was from that direction. It was not a big deal, but it meant always flying a little off-center, and it's farirly heavy on the stick.

The still-air sink rate seemed a little high at about 200 feet per minute. I'd have to check my records, but I thought the Blanik was more like 160. We found some broad lift of about 2-3 knots and I was able to climb a few hundred feet. The Krosno seemed pretty easy to control in a medium-banked thermaling turn. Part of learning the quirks of each new ship is finding just how steep and/or slow you can go in a thermal before it wants to stall out of the turn.

I did a couple of straight-ahead stalls, which were quite gentle and easy to recover. It had no tendency to drop a wing, which surprised me since I had had to hold some aileron and rudder in straight flight. Maybe that effect is more pronounced at tow speeds... in any case, it had no tendency to fall off either way in the stall. Then I rolled in and out of some steep turns. It definitely takes a lot of rudder pressure to stay coordinated coming out of turns, which will be something to work on.

The biggest difference for me was using the nose skid for landing. We discussed that I would do a "wheel landing" and then let the nose down to brake to a stop. I put the nose down quite early and then when I realized we had a lot of runway left, it would not come up again. So we stopped quite short. That's another thing I'll have to work on: keeping it balanced on the main wheel longer, until I really want to stop it.

So, one signoff is in the book. One more to go for that level. Then it will be on to the PW-6.