This is a story of an incident that occurred during my PPL at a training airport, CZVL.
Among several flight training units, the Air Cadets train with gliders at CZVL as well.
During the summer months, the gliders are generally at our airport every weekend. They will operate on the infield grass area of whatever the active runway is.
They will take off in the same direction as our circuits, get towed up a couple thousand feet AGL, release, and come back to join the circuit.
One tow plane will have two gliders going at a time.
It’s hard to coordinate timing, so usually what will happen is you will be downwind in your circuit, and you’ll be asked to extend, or if you’re already on base they’ll get you to orbit left 270 and then join final.
This will allow the glider to slip in front of you, so that you aren’t landing parallel to them.
There is a couple of training schools that use the airport so it is not uncommon to have anywhere from 2 to 8 planes in the circuit, especially if it’s the first nice weekend in a while.
They also do simulated rope breaks, where the pilot is dropped during the climb, and they are supposed to come back into the circuit.
During my PPL training, I had a rude awakening to what can go wrong in controlled flight.
A glider pilot was towed up in parallel to me off runway 34. It was a nice day, and a neat sight to have a glider just a few hundred feet off to my right as I climbed out.
Then they turn right and I turned crosswind to go off on my left hand circuit.
Downwind I’m getting ready to setup for my approach, and I hear tower on the radio. "Glider 1. … … Glider 1… … Glider 1… " …
Hmm. Now, I’m just a dumb student. He’s not talking to me, so I’m focused on my pre-landing checklist.
My instructor is doing his best to ‘ignore’ me while watching me, so I stay comfortable. He says nothing.
I call my downwind to the tower and I am cleared for a touch and go on runway 34.
I turn base. Again the radio is alive with "Glider 1… Glider 1… Glider 1… "
I turn final. I don’t see anything abnormal out the window. I set my glide path, get airspeed steady at 70, set my trim. Looking good… looking good.
I tell myself, OK, remember to look out the window this time, don’t look in fr… “GJJL FULL STOP FULL STOP FULL STOP”
“Roger Tower FULL STOP FULL STOP FULL STOP!!”
Again my instructor says nothing. He’s used to this - it’s a training airport. Things go backwards all the time.
He’s now looking out the window to watch my wheel height on flare. (I was flaring high previously).
Bear in mind that instructors will also coordinate events with the tower to test students - things like “I can’t hear you on the radio, watch for lights” or “FOD on runway, switch to other runway” and see if we can do it.
So I figure this is just a setup. Oooh was I wrong.
I flare, and keeping in mind my advice to myself to help the flare, I look deep into the front window, and I am greeted with A BIG YELLOW GLIDER, flaring on 16!
Well I tell you I make my best landing to date, eek those tires and I get on those brakes, ailerons into the wind, left rudder and park that poor Cessna on the literal left edge of the runway.
My instructor now looks over, probably to question why I am so hard on the brakes. As his gaze sets on me, I redirect him with my right finger, jabbing at the window.
You can see the look of WTF on my instructors face. He utters a swear, the only one I will hear during my entire training. “That is **, total **” he says.
The tower instructs the aircraft behind me in the circuit to overshoot.
I come to a stop and wait. Well, he said FULL STOP didn’t he?? 
No way I am continuing to roll towards a moving, unpowered aircraft.
We watch in dumbstruck as the glider continues towards us. I have my hand on the throttle, ready to put the 172 into the outfield grass. The glider then bears into the infield, and wobbles towards us.
Our wings pass with mere inches to spare.
A couple seconds later, it comes to a stop, and flops on its side. Other students run out to assist.
The radio comes alive: “Glider Ops, CALL THE TOWER NOW”
A moment of silence.
“GJJL exit at the end, contact ground 120.8 off, thank you”
My instructor shakes his head, and congratulates me on handling the situation. I continue down 34, taxi off, backtrack down the taxiway and continue on with my training flight.
In the next circuit we notice the students pushing the gliders back to base. They were shut down for the rest of the weekend.
This was hour 24 as a student pilot in dual instruction. I was barely on the 2nd page of my log book. I took GJJL on my first solo four days later.
I still question why I was allowed to fly into an obvious danger situation, when I could have been redirected while still in the air, or sent to the outfield grass to land. Did the controller expect to get an answer from the gilder pilot, having been ignored for the better part of five minutes? I was upset at being allowed to escalate so far into a safety situation when it was easily avoidable. Since I was in the final stage of descent, I could not see the glider, or you bet I would have questioned the tower a lot earlier.
CADORS 2010C1425
http://turl.ca/ussedz
Of course the details are abbreviated, and slightly wrong.
I have more glider stories, including video, but another day.
Stay alert. Just because no one answers your radio call does not mean they aren’t there.