Hi Does anybody know if the middle main undercarriage is always needed on landing or is it governed by weight and balance.Kim

Hi,Its use is determined by two factors:* Aircraft gross weight* Maximum permitted wheel loading for the ramp etc..If the center gear is retracted, it's MGW is restricted.If the aircraft is light enough to have the center gear retracted, but the pavement requires its extension to meet wheel loading restrictions, then it must be extended.I'm not sure what RW operators do - whether it is extended all the time or not, as obviously it is another set of tires, brakes etc.. to wear through use.Best regards,Robin.

The C gear is only left stowed in abnormal situations. All normal procedures have all 4 trucks hanging out.

Hi RobinThank you for your response I now know to use it. Its probably governed by company policy at most MD11 operators.RegardsKim