Hi All,

I just did the following question for CPL Ops and think I maybe missing something?

1) ANSWER - Time to PNR = 218.1 x 147 ÷ 354 = 90.5 min (91min) - Where did the 354 come from as 147+204 is 351?

Thank you for your help.

Given that the ECHO has 130gal of fuel on board at start-up for a charter flight.
The TAS is 175kt
The FPT is 260°M
The GAF wind is 100°T @ 30kt
and the variation is 6°E.
Find the time and distance to the PNR if the flight is to be conducted at 65% MCP.

Select one:
The time to the PNR is 85 minutes and the distance to the PNR is 314nm
The time to the PNR is 91 minutes and the distance to the PNR is 308nm
The time to the PNR is 102 minutes and the distance to the PNR is 325nm
The time to the PNR is 82 minutes and the distance to the PNR is 309nm Incorrect

Ground speed out = 204kt
Ground speed home = 147kt
Safe endurance = 218.1min
Time to PNR = 218.1 x 147 ÷ 354 = 90.5 min (91min)
Distance to PNR = 90.5 min @ 204kt = 307.7nm (308nm)
The correct answer is: The time to the PNR is 91 minutes and the distance to the PNR is 308nm

G'day Joshua

Could you please give me a page number so I can look it up

Cheers

Hi Stuart, It was question number 28 in the online exam prep I received.

G'day Joshua

You didn't miss anything that question was amended previously because of that typo but the system picked up an older version I have rectified that issue.

The workings are as follows you can see you were on the right path.


Ground speed out = 204kt from flight computer.

Ground speed home = 146kt from flight computer.

Trip fuel = (130 - 15 -3) ÷ 1.1 = 101.8 gal

@28 gph = 3.64 X 60 = 218.2min

Safe endurance = 218.2min

GS out = 204 kt (from flight computer)

GS home = 146 (from flight computer)

Time to PNR = 218.2 x 146 ÷ 350 = 91 min (round down to be safe)

Distance to PNR = 91 min @ 204kt = 309nm (round down to be safe)


The correct answer is: The time to the PNR is 91 minutes and the distance to the PNR is 309nm

Cheers

Hi Stuart,

Thank you very much for your help and for getting back to me so quick.

Feel relieved i was on the right track : )