The improved (often called overspeed V2) climb makes use of spare runway to permit the use of higher than minV2 speed schedules to gain additional RTOW if the AFM so permits.
We are concerned more with climb rate than gradient, although the appropriate WAT or obstacle requirements need to be satisfied. The shape of the climb versus speed curve is such that the best climb invariably occurs at some margin above V2min. As the rate of improvement decreases sharply as the peak climb point is approached, the practical limit for useful overspeed V2 scheduling is around V2min+25.
[This message has been edited by john_tullamarine (edited 06 July 2001).]