Operational Performance

Question 1

What is an ETP or CP?

Answer 1

The ETP (or Critical Point CP) is the point between two aerodromes where it will take the same time to fly to either aerodrome.

Question 2

When will the ETP/CP be halfway between departure and destination?

Answer 2

In nil wind, if there is any wind present then it will not lie halfway.

Question 3

What is the distance ETP calculation?

Answer 3

D(nm)×GS(H) / (2×TAS)

or D(nm)×GS(H) / [GS(O)+GS(H)]

Question 4

What is the time ETP calculation?

Answer 4

Dist ETP(nm) / GS(O) × 60

Question 5

What is a PNR?

Answer 5

The PNR is the point along the track beyond which there is insufficient fuel to return to land at the departure aerodrome (or even an on track alternate) with the mandatory reserves still intact. The PNR is a fuel consideration, not a time consideration.

Question 6

What is the difference between ETP and PNR?

Answer 6

PNR is a fuel consideration not a time consideration. ETP is a time consideration.

Question 7

Time PNR calculation?

Answer 7

Safe Endurance × GS(H) / (2×TAS)

Question 8

Distance to PNR?

Answer 8

GS(O) × Time to PNR / 60 min/hr