Notes on converting to a K23

These notes are designed to make the conversion from a K21 to a K23 as smooth and simple as possible. If your instructor deemed you competent enough to fly solo you can quite easily manage a K23. Therefore, there is nothing to worry about. The first flight may seem a little scary but it quickly becomes comfortable and natural.


The K23 cockpit is very similar to a K21, with the usual instruments, release pull, pedal adjustment and airbrake handle. The only difference is that the green trim lever is situated by your left arm, just next to the airbrake handle, instead of next to the control column as in a K21. This is only a minor difference and is easy to adapt to. Everything else before flight is very similar to a K21 and it is only the larger differences that become obvious when in the air.

During the flight

The only major difference when flying the K23 is the more sensitive elevator controls. This can lead to over correction by the pilot causing Pilot-Induced Oscillation where, in the K23’s case, the tail will bob up and down as the pilot moves the stick farther than necessary. It only takes about 20-30 seconds in the air behind the tug to get used to the more sensitive controls so any confident and capable pilot won’t find it a problem.
After release from the tug, which is just like in a K21, the glider feels more alive and responsive. It handles lighter and it feels more like you’re part of the glider. When flying a K23 remember that visibility is not as good as from a K21 front-seat as you are nearer the wing root and solid fuselage. This means that rear-visibility is not as much as there isn’t rear-seat canopy behind you to look through.
One thing to be aware of is that it is possible to spin a K23 so it’s important to keep that in the back of your mind whilst flying. If you fly normally this won’t be an issue though.

Approach and Landing

When opening the airbrakes on a K23 the nose visibly drops so make sure you compensate for this by trimming a little more nose up. When landing a K23, it feels very much like a K21. The airbrakes operate in a similar way and the approach and finals feel very familiar, with the exception of the afore mentioned nose drop. The flare is the same and, once on the ground, the behaviour is also very similar to a K21.
One thing to watch out for once on the ground but still moving is the tendency to rock between the tail-wheel and nose-wheel as they are spaced closer together than a K21. If you hold the stick hard back this won’t be a problem though. The u/c on the K23 is not cushioned like the K21, so you can expect a harder ride on the ground and you will feel a hard landing more, you won’t notice this with a normal well executed landing though.

Overall the K23 feels very much like a K21, with only a few differences that are easy to adjust to.

Clement Allen – February 2014