[Morison]

Gliders also tend to push the range limit on radios and sight limit of the pilots. At the 2004 Worlds we had at least 4 planes 'fly away' from sight limitations, all but one, I think, was recovered and flown back to the field.

Gliders can also sneek up on you ... a ballested, moulded ship on a speed run, you'll hear coming a LONG way away, but one that is in a cruise mode you might not.

Also remember that liability is more than just the direct damage from teh model. A park flyer hitting a car won't do much damage, but the distracted driver hitting a parked car will. Liability returns to the modeler.