2.2.3.1.2 Take-off distance required. (For performance
Class 1 helicopters only) The take-off distance required shall
be the horizontal distance required from the start of the
take-off to the point at which VTOSS, a selected height above
the take-off surface, and a positive climb gradient are achieved,
following failure of the critical power-unit at the take-off
decision point, the remaining power-unit(s) operating within approved operating limits.