"Markham pointed to the "But how projected trackline of the unknown aircraft.

We do not have any reason to believe that the unknown aircraft has an emergency, but tell them that he may be having navigational difficulties.

I have another unknown aircraft at my twelve o'clock, seventeen kilometers, very low!

Every 10 seconds brought the unknown aircraft a mile closer.

As a result, the previously unknown aircraft came to be known in the west as the "Yak-141".

At its closest point, the unknown aircraft passed within 200 to 300 feet of the President's helicopter in a horizontal direction, and 150 feet below.

Air Force pilots have several ways to check the identify of unknown aircraft.

Any unknown aircraft approaching to within, say, one hundred miles could be fired upon.

Valentich said he could see a large unknown aircraft which appeared to be illuminated by four bright landing lights.

The two men estimated the speed of the unknown aircraft to be at the very least three times that of the F-86.