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Definition of Critical Point
Unusualattitude
Topic Author
Unusualattitude created the topic: Definition of Critical Point
Critical point is usually used when
a. making sea crossing
b. flying over developed country
c. making remote area crossing
d. A and B
I think the correct answer is A and C because ETP is used to determined the time to go on and to go home when crossing the ocean or remote area whereas the PNR is used for sea crossing.
Could you please share your thoughts on this?
Cheers
bobtait replied the topic: Re: Definition of Critical Point
Both CP and PNR are useful when the planned trip will provide no other options but to return to the departure aerodrome or to continue to the destination. An over water flight would be an example of such a situation, as would a long night flight when there are no enroute aerodromes with suitable runway lighting. I suppose it could be argued that a fligh through a remote area would not always mean that there would be no suitable aerodromes between the departure point and the destination.
The big difference between a CP and a PNR is that the CP considers which would require LESS TIME, going on or returning home. A CP takes no account of the fuel on board.
On the other hand, a PNR considers only the point where going on is no longer an option. A PNR considers the fuel available at take off to permit you to return to the departure aerodrome from a point enroute. When you calculate a PNR, you are not interested in the distance to the destination, the only thing that matters is the fuel you have at take-off.
