I am currently struggling to understand the following question regarding a VOR station and an aircraft. The aircraft is found in the 30 degree radial from the VOR station at time T(1) and T(2). During the 10 minutes between T(1) and T(2) the aircraft maintains a heading of 120 degrees from magnetic north at 120 knots ground speed. The question goes like so:

I'm not quite positive of my understanding of the situation. To my understanding the heading indicates the direction the aircraft is pointing in is 120 degrees with respect to magnetic North however its course must be either be 30 degrees with respect to magnetic North or 210 degrees with respect to magnetic North, allowing it to stay in the station's 30 degree radial. Would my understanding of the situation be correct?

• If the a/c is located somewhere on the 30 deg radial and is on a heading of 120 degrees, it is flying exactly perpendicular to that radial. So, it's hard to imagine how after 10 minutes the a/c would still be located on the 30 deg radial (unless the a/c is not moving). Can you go back and check to ensure you have the specifics of your question correct. It would make more sense if after 10 minutes the aircraft was located/crossing on the 50 or 60 degree radial. Oct 5, 2018 at 17:34

### Good news: you're right to be confused!

• With a groundspeed of 120 knots and a constant ground track, after 10 minutes the airplane will have moved 20 miles in a straight line. There's no getting around this fact.

• If the airplane doesn't parallel a radial, and yet it moves, the radial it's on must change.

• If it's still indicating the same radial after non-parallel movement, the only option is that the indicator is in error. But the question removes that possibility.

• The only way I can think to make this situation possible is that maybe you've tuned the world's most bizarre VOT. But even still there's no possibility for a valid answer for the question.

The original question: