Re: Is Oklahoma City Northwest or Southwest from London? Flight Heading

Those bearings are probably both quite correct. The earth is a sphere, and the 
idea that we get when we look at a flat map can be quite false. The shortest 
distance between two points on the Earth's surface is a "great circle" route, 
that would take you right around a circumference of the earth. 

If we think of two cities at the same latitude but very different longitude, say 
Beirut and Los Angeles (both 34 deg N latitude), then we might say that Beirut is 
East of LA and LA is West of Beirut. But the shortest route from Beirut to LA 
actually goes a long way North -- over the Southern tip of Greenland! If you 
followed the 34th parallel the journey would be much longer.

It is easiest to see this if you actually get a large globe of the earth, and 
check it out.