SPINS - HOW TO DEMO (IN A K13)  ***NOTE current caution/prohibition on spinning K13s (Aug 2021)***

(I think this all pretty much applies to the Puchacz as I remember and probably other 'spinnable' gliders, too.)

ALL TO BE STARTED ABOVE AT LEAST 2000FT AGL

Unless they have been well prepared most people will yank the nose in the air and stamp on the rudder in an attempt to make the glider spin.  Apart from the fact that this usually doesn't work, it is missing the point.

An instructor should be able to explain the various 'catch-ya' scenarios and fly them convincingly so that his students will be suitably cautioned.  Actually it is the whole point! 

Spin off an under-banked, over-ruddered turn. Scenario = low final turn: trying to get round the turn with rudder instead of using bank.  You are scared to let the wing to go down so near to the ground so you try to turn the glider with the rudder (and keep the wing up).

Establish the straight and level stall speed first. Go into a really shallow banked turn at only just above the stall speed (see below). Smoothly (but reasonably rapidly) put in full rudder. It will want to roll in but DON'T let the bank increase - keep it at the original angle - this will require a lot (all) of out-turn stick. If it hasn't already stalled, gently pull back the stick to the backstop and it WILL spin. You will end up with stick in the back out-turn corner. Any tendency to relax the back pressure will stop it spinning and produce a spiral dive. Recover from this immediately: don't hang on thinking it will spin - it won't, and you might over-stress the glider.

Note: as it enters the spin the controls will have become 'crossed' with the stick fully back.

Spin off a steep thermal turn. One scenario (there are others) is that you are 'doing everything your instructor ever told you when thermalling'. "Bank steeper, fly slower, keep the yaw string in the middle."

If you do all that and fly too slowly it will spin but some tips to get it to work are:-

As above, do NOT go into the turn too fast or it will take for ever to slow down or you may just end up in a spiral dive. Go in only just above the speed you think it will stall at the planned bank angle - which make reasonably steep (although it doesn't have to be extreme). Slow it down the last couple of knots.  The stick will now be near or on the back stop.  As you do so the wing will want to drop - hold it up. The glider will slip into the turn (tail in) and the yaw string will indicate you need in-turn rudder. Apply this (usually needed full and fairly rapidly in an attempt to keep the string in the middle) and it WILL spin as long as you keep the stick all the way back. Any tendency to relax the back pressure will stop it spinning and produce a spiral dive. Recover from this immediately: don't hang on thinking it will spin - it won't, and you might over-stress the glider.

Note: as it enters the spin the controls will have become 'crossed' with the stick fully back.

Spin off a failed winch launch. Scenario = mishandled winch launch recovery.

Dive a little bit (doesn't need much) and pull up to get the glider in a steep winch launch attitude at say 55-60kts. Say "bang". Lower the nose too slowly - i.e. so that as you go over the top you are only doing say 20kts. If you push over too hard, the demo won't work! As the horizon comes up so that you are in the 'normal gliding attitude' pull back on the stick in an attempt to maintain that normal attitude. If you mis-time this and the nose goes down too far, the demo won't work (so just carry on and dive a bit, pull up and try again). If you successfully capture the state of 'normal attitude at 20kts', you are obviously deeply stalled. It seems to work better if you just hesitate a tad (say 2-3 seconds*) in this state and then do a CO-ORDINATED turn. It WILL spin.

*You can put a bit of patter in here e.g. "We are in the normal attitude but too slow.  Look what happens if I try to turn..."

Note: here the ailerons/rudder are in perfectly normal positions (but the stick is fully back) when it departs but it spins because you are deeply, deeply stalled. (And, by the way, therefore you require a lot of height through which to fall in order to re-gain flying speed).

(Should really follow this with a demo of a correctly flown recovery in spite of 20kts over the top.)