Simviation Forums

On a recent flight from sydney to hawaii, I chose to fly using high altitude airways but the flight plannerchose a route that was about 50% longer than the point-to-point method I could have used! It took me almost dead east from aus untili was almost dead south of hawaii then turned 90* and into hawaii!!!!!!! Thats not economical i cried! Then I wanted to fly UK to Cuba, so again I chose high altitude airways in the flight planner to see my flight plan take me down as far as Brazil before heading north-west to Cuba!!!! SoI thought perhaps following low-altitude airways would give me a better route - which promtly tried to take me over the north pole and down over canada/us/cuba. Now when I was a passenger on this flight for real, we flew over the north atlantic and down the east coast of America. Now as MSFS is 'as real as it gets' why on earth is it giving these ridiculous routes and making me rather fly point to point using the GPS?

John

yeah that happened to me,
I was flying from newyork to switzerland in a 777-300
And it took me the long way around the earth. So i had to refuel like twice!

Dont know why, maybe the f/p software developement was co-spondored by BP or Exxon.

cheers dave, wasnt sure about that, - will give it ago now!

John

You chaps probably know far more than me about navigation. I've forgotten most of what I once learned & am probably preaching to the converted. You might be interested in what's called Great Circle navigation. http://williams.best.vwh.net/avform.htm
The most direct route is not necessarily the shortest. I don't know if the plotter in FS uses this concept.

The most direct route is not necessarily the shortest. I don't know if the plotter in FS uses this concept.

....Interesting Hagar...but WELL over my head with all those formulae...definately only for Maths. graduates with additional PHDs I would imagine. I'd be better off digging that very long tunnel the guy talked about in the Intro......commoner

[quote]....Interesting Hagar...but WELL over my head with all those formulae...definately only for Maths. graduates with additional PHDs I would imagine. I'd be better off digging that very long tunnel the guy talked about in the Intro......commoner

...mmm...I THINK you mean that the Earth will have turned on it's axis by the time you have flown for say 10 hours eh?..........Still like the tunnel idea for travelling to antipodean destinations ......at least that would be still in the same place....wouldn't it?...... :-/.... commoner

It is a well known that the shortest distance between two points is a straight line. However anyone attempting to fly from Los Angeles to New York on the straight line connecting them would have to dig a very substantial tunnel first. The shortest distance, following the earth's surface lies vertically above the aforementioned straight line route. This route can be constructed by slicing the earth in half with an imaginary plane through LAX and JFK. This plane cuts the (assumed spherical) earth in a circular arc connecting the two points, called a great circle. Only planes through the center of the earth give rise to great circles. Any plane will cut a sphere in a circle, but the resulting little circles are not the shortest distance between the points they connect. A little thought will show that lines of longitude (meridians) are great circles, but lines of latitude, with the exception of the equator, are not.

Doug...!
I read that from the beginning to the end...
...then, from the end back to the beginning...

And I came to the conclusion that the answer's....

A Lemon.

Paul.

The planes in the above example seem to be doing a lot of damage to our delicate Planet.... ... ... ...!

...mmm...I THINK you mean that the Earth will have turned on it's axis by the time you have flown for say 10 hours eh?..........Still like the tunnel idea for travelling to antipodean destinations ......at least that would be still in the same place....wouldn't it?...... :-/.... commoner

LOL I rather like the idea of tunnelling to Australia myself, except for one important thing. I hate tunnels & wouldn't even consider going over to the Continent via the Chunnel.

Doug...!
I read that from the beginning to the end...
...then, from the end back to the beginning...

And I came to the conclusion that the answer's....

A Lemon.

Good one Paul.

Neither of you are as daft as you like to make out. I'm sure you understand what I mean. Maybe I can find a simpler example rather than all those complicated formulae.

...mmm...I THINK you mean that the Earth will have turned on it's axis by the time you have flown for say 10 hours eh?..........Still like the tunnel idea for travelling to antipodean destinations ......at least that would be still in the same place....wouldn't it?...... :-/.... commoner

But the atmosphere moves with the planet - if it didnt then we would be constantly barraged with a 465.4 ms-1 (mach 1.4) wind blowing from the east!!!! which we obviously dont! (imagin having that as a tailwind) therefore the destination's position does not alter! also think about it - if that was so, how would a helicopter hover!?

John

......JB...The Helicopter isn't actually hovering is it other wise it would just have to wait 'til it's destinanion passed by underneath it and land ....MY guess is that it is flying forwards/backwards/sideways as neccessary to keep the same spot underneath it as the earth spins......that right or not?...commoner  ;)

.....how would a helicopter hover!?

John

Helicopters don't hover in the flight sims....
They spin around in ever-decreasing circles until they finally crash....Wind or no wind... ...!

That's why the sensible ones amongst us fly aircraft fitted with wings, and the wind tends to help keep us airbourne... ...!

LOL...!

Cheers John...!

Paul....pulling your leg... ... ...!

Try this. http://plus.maths.org/issue7/features/greatcircles/

how would a helicopter hover!?

I've often wondered that myself. It ain't natural.

Seriously, I think talking about helicopters hovering is irrelevant & confusing the issue.

Excellent read, Doug...!

Tomorrow I'm going to Sainsbury's via Puerto Rico...!

...with my GPS Navaid pinned to my jacket...

LOL...!

Cheers Doug.... ...!

Paul.

...actually, the diagrams in the article explained it admiribly... ...!