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skyhigher
11th Mar 2007, 09:30
hey,

does anyone have any useful rules of thumb or calculations for helping students plan climbs? or using crp 5's

ie. add 45 secs per 1000' etc....

how is this worked out?

thanks.....

LEVC
11th Mar 2007, 10:25
In some Cessna models you have a table where you get Time ,Fuel and Distance to climb to the altitude you aim for.

I used to fly some models where there aren't tables, what i was taught and used afterwards was Climb at Vy and usually it will give you an average of 500 fpm, then you can calculate the time , knowing your speed (Vy) you get your distance, i used to add 1 USG/hour to the maximum fuel burn figures you get from the tables to calculate the fuel burn on the climb, if you have already flown te model you can adjust the ROC if you know is well below or well above 500 fpm.


There is a rule of thumb which i can't remember for the fuel burn dependant on the Horsepower your engine is rated, aparently it works good , i have never used it though.

veetwo
11th Mar 2007, 16:04
Piper are the same, if you look in the POH there will be graphs to determine Fuel time and Distance to climb or descend based on either VY or cruise climb speed (all the associated conditions will be defined on the graph itself). You usually go in with temperature and pressure altitude and it will spit out Gallons per hour, nautical air miles and time in minutes. You'll need to adjust the NAM for known wind if you want ground distance.

FlyingForFun
11th Mar 2007, 22:44
I have to admit that, outside of written exams, I've never yet encountered a situation where I've found any need to make allowances for the time taken to climb.

The climb, for a light aircraft (especially VFR) tends to be so short (and subject to change due weather, if VFR) compared to the rest of the flight that it barely makes any noticeable difference to the time on the flight. On the rare occassions that a reasonably long climb is planned, it's usually sufficient to note that you may be very slightly late at your first way-point.

Having said that, if you really want to work it out accurately, tables in the POH might only be for Vy - which is fine if you plan a Vy climb, but if you plan any other speed, you'll need to use the technique LEVC describes.

FFF
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barrow
11th Mar 2007, 23:40
Rule of thumb: fuel. 0.45 pounds per hour, per horse power. {lean to peak}

Turbo or supercharged: 0.55 pph/ph [lean to peak]

Turbine: 0.75 pph/ph

300 hp normally aspirated using 75% power in cruise, leaned to peak EGT.

300*0.75=225hp * .45=101.25 pph divide by six = 16.8 gph.:D