I think a distinction needs to be made between lift, and coefficient of lift.. .. .Lift is greatest just after take-off. The main purpose of lift is to counteract weight, and weight is greatest just after take-off when there's maximum fuel. Any extra lift over and above the weight causes the aircraft to climb, which is exactly what it does just after take-off.. .. .Coefficient of lift is greatest at the point of the stall - this is a basic property of aerofoils. With regard to what phase of flight this relates to, I'd guess (although I'm not certain) that it would be during the flare, just prior to landing.. .. .FFF. .----------