With some aircraft, all wheels on the ground may not provide a positive angle of attack so it's necessary to lift the nosewheel when you have sufficient elevator authority in order to generate lift; many a time I watched Illyushin IL 18s depart from Glasgow and the nosewheel was always lifted well before takeoff; likewise FRCs for the JP Mk5 say 'nosewheel off at 85kt, rotate at 95kt'.
Last edited by chevvron; 1st Nov 2020 at 13:30.