Story published yesterday in the Times:
http://www.timesonline.co.uk/tol/new...cle3516551.ece
Virgin Atlantic has quietly abandoned a plan to tow Boeing 747 jumbo jets to special “starting grids” at the end of runways after the aircraft manufacturer found that pulling the landing gear would seriously weaken it.
Presumably the same problem would apply if the a/c is 'towed' by motors in the nose wheels as proposed by Wheeltug....