View Full Version : PNR and Crit Point
miles offtarget
2nd Jun 2004, 00:05
Could someone please remind me of the simple formulae to determine single leg PNR and CP.
I remember that it is along the lines of E x H over O + H or something, but took ATPL Navs 6 years ago and don't have to engage the grey matter too often these days.
Thanks in advance.
Miles Offtarget
Thunderbug
2nd Jun 2004, 07:31
Miles
Try This....... (http://users.pandora.be/joe/part.5.htm)
T'Bug :ok:
ROB-x38
2nd Jun 2004, 10:13
Simple straight line formulae:
PNR = (E.O.H.) / (O + H)
CP = (D.H) / (O + H) (gives distance from departure point (home) to CP)
E = endurance in hours
O = ground speed on
H = ground speed home
D = total distance
No_Speed_Restriction
2nd Jun 2004, 11:04
Or if you want the full blown PNR Version:
Endurance / ((Sfc2Eng / Gs out 2Eng)+(Sfc1Eng / Gs home 1Eng))
:yuk:
miles offtarget
2nd Jun 2004, 16:24
Just what I needed. Bringing a Caravan across the pond this week so will be useful.
Thanks.
Was asked to do an assessment on a First Officer being upgraded to Captain some years ago, and as all the PNR/CP data was on the computer flight plan, asked him to compute the PNR/CP manually.
His answer was spot on, using the 'ole Jeppesen circular wizz-wheel.
Promotion approved.:ok: :ok: