Which technique should a pilot use to scan for traffic to the right and left during straight-and-level flight? How can you determine if another aircraft is on a collision course with your aircraft? What preparation should a pilot make to adapt the eyes for night flying?
Because of this designation, longitude is measured in degrees west or east of the Prime Meridian. For example, 30Â°E, the line passing through eastern Africa, is an angular distance of 30Â° east of the Prime Meridian. 30Â°W, which is in the middle of the Atlantic Ocean, is an angular distance of 30Â° west of the Prime Meridian.
Longitudes on the other hand are imaginary lines that run  vertically across the earth. The latitude of a point on the Earth's surface is the north or south angular distance between the point and the equator. The longitude of a point is the east or west angular distance between the point and the Prime Meridian.