1/ The 747’s Body Gear Steering system is automatic and starts to operate when the nose gear is turned more than 21 degrees. The 747-100/200/300 had an OFF – ARM switch. The 747-400 was entirely automatic (no switch).
2/ Yes it counter steered to reduce tire scrubbing and improve the turning radius.
3 / It could steer up to 13 degrees.
4/ I am not a pilot so can’t offer any operating experience but I think it was a system that worked in the background and no-one thought about it until it malfunctioned which was very rare.
5/ It was standard on all 747 models (not 100% sure about the SP).
6/ It could not be used for xwinds. It had to turned off for takeoff and only turned on after landing (automatic on the 747-400). It was connected to the TO Config warning system so the horn would sound if both body gears were not centered and locked when applying TO thrust.
9/ As for other aircraft the 777 steers the rear axle. I think the A380 steers the rear axle on the body gear. If you go back in time the DC8 allowed the rear axle on the inside of the turn to unlock and caster to improve turning radius. This was deleted on the DC8-62/63. I think some of the large Russian aircraft (AN124?) can steer main landing gears but know nothing about them.
Last edited by CV880; 20th Apr 2015 at 02:11.