Figure 4.5-2

For example, Figure 4.5-1 shows a balloon with a width of 50 nm (mass of air) moving east

at 50 knots. If an aircraft were flying eastward at 50 knots inside the balloon, at the end of

one hour, it will have traveled a total of 100 nm toward the east.

Figure 4.5-1

On the other hand, if an aircraft moves eastward at 50 knots while the balloon moves

westward at 50 knots the aircraft will not move over the ground (Figure 4.5-2).

Figure 4.5-2

The aircraft will, however, travel from one side of the balloon to the other regardless of the

fact that the balloon is moving westward at the same rate the aircraft is flying eastward.

4.6-109