all flights are not straight lines, you would fly into buildings and hills.
it’s all spherical.
Another reason is that some aircraft are limited for over water travel. They need to be within X number of miles from land. Places like Newfoundland, Greenland, and Iceland have airports which is nice to know if your 2 engine jet aircraft loses an engine.
Take a look at number 38 on this link. It’s a map showing the longest straight line over water in the world. On the 2d map it’s curved, but when you watch the animation on the globe you can see it’s straight.
http://beforeitsnews.com/watercooler-topics/2013/08/40-amazing-maps-you-have-never-seen-2433780.html
The modern equivalent is to use Google Earth and use the line tool to draw a straight line between two points.
This looks like as good an excuse as any to link this clip.
Yes, they can and do fly over Cuba or sometimes just off to the side of it. The U.S. has a military base on Cuba after all. There are North-South air corridors over Cuba that can be used just by requesting routine prior authorization even for U.S. airlines.
I have flown over Cuba or just off the coast of it a bunch of times going from the Northeast U.S. to the US Virgin Islands.
“You can’t do that!”
“Why not?”
“Because it’s freaking me out!”
Assuming you mean Johannesburg, South Africa, from Los Angeles, USA, show me how that works on a globe map.
Looks more like East itself at departure from LAX, bearing 93.8 (bearings map); (ortographic map)
Due East won’t get you below the Equator, ever. Slightly “north of due East” may get you to South Africa, but that’s the long way. East, then south, or slightly south of East (93.8 degrees), may work.
SoP, it may be the orthographic map that made you think that you had to “start out flying slightly north of due East,” but it doesn’t work that way.
Surely all great circles, except ones directly over the poles, must go due east/west at some points?
Anyway, maybe **SoP **meant to say slightly north of west?
…except of course that way round the great circle would be further :smack:
Wow, learn/realize something new every day. I always assumed it was a longer route, but they chose it for strategic reasons. Forgot we live on a sphere…
Note that your directional heading doesn’t stay the same for an entire journey on a globe —it changes slowly. Yes, you will eventually cross the equator if you go in a straight line that starts out heading due east.
Not if you head east (90º) and continue heading east (90º), then continue heading east, etc. You are assuming a “straight” line that begins with an eastern heading, then bends with the earth. If you bend with the earth, you are no longer heading east, and your compass heading will change. You will never cross the Equator.
Flying across the Pacific, we always seem to be doing an arc. I’ve often wondered if this was due to the curvature of the globe really making it the shortest distance or if it’s to stay closer to land in the event an emergency landing is called for.
Well, here’s the great circle route (that is, the shortest one) from Bangkok to LAX. On a flat map it does look like an arc, but it’s undoubtedly the shortest straight line path. You can plug in different airports at that site, as others have done upthread.
Edit: This projection makes it a bit clearer.
I think they’ll fly the most efficient route they’re allowed to. But even at ETOPS-180, parts of the eastern Pacific are off-limits.
I would like to correct myself. The last line should read: Since your compass heading will change, you WILL cross the Equator. If you keep a constant 90º heading, you will not.
Magnetic or true 90º?
They are two different directions.
Most non pilots or non long distance sailors do not make or understand the distinction in my experience.