Calculated Industries 8703 User Manual
Page 26
24 — H
OT
R
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C
ALC
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KEYSTROKES DISPLAY
0.
3. Enter current weather conditions:
TEMP S 60. °F
(Absolute Pressure)
P-ABS S 24.72 INHG
(Moisture/Relative Humidity)
RH% S 39 %
4. Calculate ADI:
ELEV S 0.
ADI 81.94 %
D-ALT 6662.18 F
Record the calculated ADI of 81.94% and density altitude of 6,662
feet in your log.
5. Calculate a fuel correction index, which is simply the current
ADI of 81.94, divided by the baseline ADI of 92.038, then
multiply by 100:
89.028445
The fuel correction index is about 89%, indicating air density is
about 89% of the air density from which you baselined your jet
numbers. In other words, the new air density has gone down about
11% from your baseline air density calculation. Some experts say
that as a general rule, a change of +/– 4% or more in air density is
enough to consider a jetting change.
Also, notice that the density altitude at the new track location,
about 6,662 feet, is much higher than the previous track’s density
altitude of about 2,813. Typically, as density altitude goes up, you
may require less fuel whereas if density altitude goes down, you
may require more fuel.