wesleyj said:
True, but they dont experiance nearly the stress that a powered aircraft does, they stay in the trailer during strong winds and turbulance, they also are not on the line everyday being used and abused by the neophytes.
Not a good comparison.
really? have you ever flown a glider? especially in a contest? How often does your typical plastic airplane exceed 2 G's in a flight? maybe when the student mucks up a stall recovery or goes too steep in a steep turn.
In order to stay in the strong part of the thermal (the core) the glider pilot must bank steeply and fly slowly. G forces of 2+ sustained are the norm, not the exception. Once the pilot tops the thermal he dives for the next one. This is not done at a leisurely pace either. The stronger the lift was, the faster he dives. As soon as he hits the next thermal that he wants to climb in, he hauls back on the stick, transitioning from a dive of perhaps 80-90 knots to thermalling speed of 45-50 in only a second or two. Then rolls back into that 2+ G turn. This is continued over the entire course. Most contest tasks are out and returns or triangles. To maximize speed, as soon as the pilot thinks they can dive for the airport and make it, they do so. Ideally this dive will be at the maximum speed possible. Vno is common, some push it up even higher. This allows them to convert all their altitude into speed. They make a low pass (under 100 feet) to finish the race and then they pull up sharply, trade speed for altitude, and fly a pattern to land.
If the glider isnt flying in thermal lift, but exploiting wave, the forces are even harder. The glider is typically towed through the rotor to get to the wave. yes thats right, the rotor. The place that all power flying handbooks tell you not to go. Once contacted to the mountain wave, the lift is tremendous. This really is powerful stuff, which is why most powered flying manuals instruct you (wisely) to steer clear. Many gliders have broken apart in flight while flying mountain wave. this is why the pilots wear parachutes.
Many of the original fiberglass ships (Cirruses and Libelles, etc.) have been flying these profiles regularly for the last 40 years.
This does not sound anything to me like the typical cirrus or diamond mission of takeoff, autopilot on, cruise, and land.