PNR and Crit Point

[miles offtarget]

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]

Miles

Try This.......


T'Bug

[ROB-x38]

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]

Or if you want the full blown PNR Version:


Endurance / ((Sfc2Eng / Gs out 2Eng)+(Sfc1Eng / Gs home 1Eng))

[miles offtarget]

Thanks

Just what I needed. Bringing a Caravan across the pond this week so will be useful.

Thanks.

[411A]

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.