ITCZ - you're making life very difficult for yourself and besides, doesnt anyone carry a god-damned whiz-wheel around anymore?
Chuck out that damned Palm Pilot for starters and I'll explain a method (which you can fine tune for the 146' figures).
I can work out a PNR within seconds knowing some basic figures about your aircraft performance.
Firstly - work out the Specific Air Range (kg/nm.hr) for normal cruise which for the 146 would probably be about 5kg/nm (just a guess).
Secondly work out the SAR for a depressurised case (cruise at 10,000') at the specific fuel flow for that altitude -probably about 8kg/nm.
Add the two together - now thats 13 kg/nm total which will allow you to work out a PNR going from your present position with all 4 engines burning to a point, depressurise (most limiting case) and return depressurised at 10,000' .
Now for instance if you are doing say a Melbourne to Perth flight and you are say abeam Adelaide (100 south which makes little difference looking at the geometry of a return to ADL) and have 10,000 kg.
You need legal statutory reserves of 30 minutes fixed reserve (call it say 1240 kg) and your charts are probably worked out for an arrival overhead at 1500 ft AGL - so add manoeuvring fuel from 1500 to land (say 160 kg) plus any required WX.
Subtract your statutory reserves (in this case 1240+160 ) which is 1400 kg from your available fuel Abeam ADL (10,000) which gives you 8600kg available fuel.
Use your whiz-wheel and work out 8600 divided by 13 and that will be a rough distance to your PNR (661 nm or so).
Easy or what?
Once you know the variables it will only take seconds to work out a rough Depressurised PNR.
This is the most limiting case and if you can make a Depressurised PNR then anything else is easy.
If you want to work out any other PNR with say all engines operating dont forget the 10% fuel to be subtracted and any traffic holding to give the available fuel.
Just remember this is a rough figure (but surprisingly accurate) and takes only seconds.
Those individuals that fight over a few kg here and there and argue over a few nm are probably twits that dont think clearly or see the big picture and besides - no real methods account for the fuel required to do a 180 degree turn to go back or pilots cruising at Flight Levels would rarely know what the wind is doing at 10,000ft or whatever level they will fly depressurised!
Its academic only but important to know where you stand in terms of situational awareness.
Last edited by TIMMEEEE; 13th October 2002 at 23:27.