From my experience, it is virtually impossible to walk into one of the smaller gliding clubs and become a tug pilot. The usual requirements are that you are a long standing member who flys gliders as well. The larger clubs very often have different criteria. I personally know a PPL with no gliding experience who recently started aerotowing at one of these large (seven day/week operation) clubs just because he asked! Glider pilots see the aerotow as an expensive means to an end - they are trying to "Get away" ie find a decent thermal and soar. I believe some gliding experience is helpful as the glider pilot will potentially be very critical of a tuggie who places them in the wrong area, scares them to death with a low level tour of the local scenery and worst of all avoids those horrible bumpy bits! You will be tasked with getting the tug up and down in the most economical manner -without either cooking the engine on the way up or shock cooling it on the way down. You will be expected to land from an approach - go arounds are usually frowned upon, although this is not usually a problem as you will probably do the average ppl's years worth of landings in a day. As an added bonus, there may be 50 gliders soaring in the local area to avoid as well!
Taildragger experience is becoming less important as many large clubs are now using Robin tugs because of the reduced operating costs over Pawnees. They do need plenty of tarmac to get the combination airborne but climb well thereafter. The Pawnees and similar tend to be used by clubs with short or rough grass runways as rough grass knocks hell out of nosewheels, particularly when the aircraft may take off and land 40 or 50 times a day! The accidents mentioned with Pawnees were not directly aerotow related. Two of them were elderly pilots becoming incapacitated in flight and another was a traditional taildragger nose over! It is true that you can get a rough ride whilst towing and you may at times find that you are flying with a control surface deflected (usually rudder) if the glider gets out of position. The big danger is an accelerated climb by the glider (think waterskier on the end of a rope) you run out of down elevator and are rapidly pitched nose down. This is not a big problem at height, but a disaster close to the ground.
Most tuggies keep a hand very near the release during the initial climb..........
My personal favorite is still the Pawnee.
