National Geographic NG770B, Instruction Manual

Page: 6 / 14

(3) Flight Distance
Example: Obtain the air distance when the air speed is 180 knots
and the flight time is 40 minutes.
Operation: Align "18" on the outer scale with the SPEED INDEX on
the inner scale. Then "40" on the inner scale corresponds to "12" on
the outer scale. Thus, the air distance of the flight is 120 nautical
miles.
(4) Rate of Fuel Consumption
Example: Obtain the rate of fuel consumption (gallons/hour) when
the flight time is 30 minutes and the fuel consumption is 130 gallons.
Operation: Align "13" on the outer scale with "30" on the inner scale.
Then the SPEED INDEX on the inner scale corresponds to "26" on
the outer scale. Thus, the fuel consumption is 260 gallons an hour.
(2) Knots (Air Speed)
Example: Obtain the knots (air speed for 240 nautical miles with a
flight time of 1 hour and 20 minutes.
Operation: Align "24" on the outer scale with "80" on the inner scale
(time scale). Then, the SPEED INDEX on the inner scale
corresponds to "18" on the outer scale. Thus, the air speed for the
flight is 180 knots.
4