Definition of 'critical point'?

[Exaviator]

Hi Jim,

CP is defined as the equal time point and usually based on an engine failure taking into consideration the resulting reduced airspeed. The formula to calculate a C.P. is:

Dist x H Where H = G.S Home all engines
O + H Where O = G.S. Out & H = G.S. H at reduced TAS

If you use the same TAS above and below the line it becomes a simple equal time point for a single engine aircraft.

On long haul four engine aircraft we calculate a C.P. for both one engine out and two engines out.