View Full Version : CP problems
hussaing_6
12th Feb 2009, 13:15
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
12th Feb 2009, 18:38
Is that the whole question?:bored:
Andy_20
12th Feb 2009, 18:41
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
12th Feb 2009, 18:43
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
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)