Dave Springford wrote:
My club is buying a K-21 for student training and I am wondering if a
tail dolly is necessary for ground handling?

We plan to get the tail wheel option - not the tail skid.

Does the K21 balance like the Twin Astir so it is easy to turn on the
ground when towing it back to the launch point?

When empty, does it sit on the main and tail wheel, or main and nose
wheel.

Anyone with experience operating a K-21 please advise

Just to add to the responses already present, my club has an ASK-21 and a
Twin II and I find them to be essentially identical in ground handling.
(Air too, but that's another subject.) It's certainly possible to manage
without a dolly, but it's much nicer with one. The fact that we don't have
one for our Grob is a small but continuing source of annoyance. It's
particularly handy when maneuvering behind the tow car with a single
person handling the glider.

--
Michael Ash
Rogue Amoeba Software