12 / 20
An aeroplane flies from A 59°S 142°W to B 61°S 148°W with a TAS of 480 kt. The autopilot is engaged and coupled with an Inertial Navigation System in which AB track is active.On route AB, the true track…
  • A
    varies by 10°.
  • B
    varies by 4°.
  • C
    decreases by 6°.
  • D
    increases by 5°.

Refer to figure.
As airplane follow INS track, so it follow a great circle.

As we are in Southern Hemisphere and heading west, track increase.
Track increase same as convergency between 2 locations.

Convergency = Sin mean latitude x difference in longitude = 0.866 x 6 = 5.19

True Track increases by 5˚

Your Notes (not visible to others)

This question has appeared on the real examination, you can find the related countries below.