CP problems

[hussaing_6]

Hi guys. Can someone help me out with the following problem regarding CP?

Calculate the time and distance to the CP from P to R via Q. Given:

Distance P to Q - 250nm
Distance Q to R - 400nm

G/S:

P to Q - 153 kts
Q to R - 190 kts
R to Q - 163 kts
Q to P - 205 kts

Been trying this one out but don't seem to get it... :ugh: :mad: ATPL!

[Andy_20]

Is that the whole question?:bored:

[Andy_20]

My notes regarding the formula for CP:

ETP or CP (Equal Time Point) = (Sector Distance (D) x Groundspeed Home (H)) / (Groundspeed On (O) + Groundspeed Home (H))

Engine Fail ETP or CP =
1. Find failed Engines G/S (On and Home with Nav Comp)
2. Work out ETP. (As Above)
3. Work out time with all Engine TAS

[Reluctant737]

You need to know fuel burn rate at each GS, and your total fuel on board to work out that question :ok:

Edited to say, forget that ^^^, misinterpretation! :p

[bsal]

Calculate the time and distance to the CP from P to R via Q. Given:

Distance P to Q - 250nm
Distance Q to R - 400nm

G/S:

P to Q - 153 kts
Q to R - 190 kts
R to Q - 163 kts
Q to P - 205 kts

Critical Point formula
X=DxH/O+H D=Distance H=Homebound speed O=Outbound speed
Take the average speeds for this question.

X=650x184/171.5+184=336NM

Time=Distance/Outbound speed
T=650/171.5
T=1.96Hrs (1H 58min)