FORMULA,S FOR PNR AND CP
 

Could someone please gently remind me of the above as a friend has asked for them and i threw all my nav books away after i passed them, but kept my techs.Thanks in anticipation.

CP

D *[H]
------=CP distance from dep.
[O+H]

D=Distance
H=GS Home@ N-1
O=GS Out@ N-1

CP dis.
------=ETE to CP
GS @all eng

PNR
constant fuel flow D = (E * O * H)/(o+H)
d=(endurance (hrs) * g/s out ) g/s home)
___________________________________
G/s out + g/s home
flow = kg per gnm
____
G/S

G/s = gnm per kg
____
flow


I think


[This message has been edited by dv8 (edited 20 June 2001).]

dv8

Wow, that's impressive!

I was scratching my head trying to remember but realised I probably forgot 90% of the crap I had to know to jump through the CAA's hoops!

A memory is a terrible thing to waste (unless you can look it up).

dd

dv8
While you have the books out could you come up with one for equal time points(ETPs)?

Thanks boy's but credit where it's due

The CP formula is from my company's Ops. Man.

The PNR is quoted from a fellow PPRUNE(r) Bubbles
For ETP try search in Tech Log underPNR usage
dv8 http://www.stopstart.fsnet.co.uk/smilie/cool6.gif

[This message has been edited by dv8 (edited 22 June 2001).]

Here is a little tip for your friend to remember which way round the PNR formula goes.
It is "Scotland sits over England" ie:- Cross of St Andrews (times sign) is over the cross of St George (plus sign).

Sad I know but every little helps in those pesky exams!

[This message has been edited by airtaxi (edited 23 June 2001).]

Engineer,

A Crit Point (CP) is another name for the Equal Time Point (ETP). The answer given above for CP distance is therefore the ETP distance from departure. If you divide this distance by the groundspeed (outbound), you get the time to the ETP/CP.

Thanks to all for your replys,much appreciated

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STILL CHASING ALL THE BELLS AND WHISLES