2. Speed (Ground Speed) Calculation
Question: What is the speed (ground speed) of an airplane when it takes 1
hour and 20 minutes to fly a distance of 240 nautical miles?
Solution: Align the 24 on the outside scale with 1:20 (80) on the inside scale.
At this time, 18 is aligned with the SPEED INDEX (Y) on the inside
scale, and the answer is 180 Kt.
18 19
3. Flying distance calculation
Question: What is the flying distance traveled in 40 minutes at a speed of 210
knots?
Solution: Align the 21 on the outside scale with the SPEED INDEX (Y) of the
inside scale. The 40 of the inside scale is now pointing to 14, and
the answer is 140 nautical miles.
