70 seconds duration illustrated here.
1500m impact location from shore.
6.800m from the beginning of the runway requires
average speed of 350kph to cover the distance in 70 seconds which means that a/c shouldn't have a problem with lack of speed considering zero velocity at the beginning of the take off run.
4300m from runway threshold would require app. 220kph average speed which seems much more applicable for the stall scenario. I conclude we talk about 70 seconds time when airborne excluding t/o run.
