Are there any 'straight-line' flights?
Technically the shape of the Earth is a Geoid
Both the geoid and oblate spheroid (ellipsoid) are approximations.
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Far below you mighty Sky Gods there are plenty of people trying to fly in straight lines. I say trying because "the air traffic police" may send them on different straight lines to their chosen ones. Their chosen straight lines are called rhumb lines. Now the really rum thing is that having flown a straight line you appear to in real time to have flown round the S-bend.
Now this problem was brought home to me when I flew from Seattle Tacoma to Narita. We took off and flew up Paget Sound. Oh well must be a noise abatement thing. We continued on with no apparent turn East of Victoria and slowly over Vancouver Island and out to sea. I consulted my magazine for the film and audio channels. I studied the fold out map and there was our route a slight curve over the Pacific to Japan. Now lunch was served and cleared away when an announcement was made that we were now 60 miles North of Anchorage! I decided to take a serious interest in where we being taken. Kodiak Island past below and we were going East. Soon the sea was full of icebergs next stop Siberia! Now we all know what happens when you pass into Russia but what could I do about it back in seat 54g. Many boring hours later there were suddenly paddy fields going past my window.
That's how I learnt how much a great circle can vary from the simple old rhumb straight line well away from trigger happy blokes in Migs.
Now this problem was brought home to me when I flew from Seattle Tacoma to Narita. We took off and flew up Paget Sound. Oh well must be a noise abatement thing. We continued on with no apparent turn East of Victoria and slowly over Vancouver Island and out to sea. I consulted my magazine for the film and audio channels. I studied the fold out map and there was our route a slight curve over the Pacific to Japan. Now lunch was served and cleared away when an announcement was made that we were now 60 miles North of Anchorage! I decided to take a serious interest in where we being taken. Kodiak Island past below and we were going East. Soon the sea was full of icebergs next stop Siberia! Now we all know what happens when you pass into Russia but what could I do about it back in seat 54g. Many boring hours later there were suddenly paddy fields going past my window.
That's how I learnt how much a great circle can vary from the simple old rhumb straight line well away from trigger happy blokes in Migs.
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"straight line" or "same heading"?
not the same thing, even ignoring the shape of the Earth.
That's because as the location of magnetic north is not at the top of the globe, so as we move around, even with the same country, the compass will show different readings for the same direction. (it is slight, but it does change)
So if you start in, say Southern California and fly to Oregon in a straight line, you won't be on the same heading the whole way, because the magnetic deviation changes along the route.
Now, for what you might think of as very short flights, say 100 miles or less, it is possible to fly in a straight line, and have that bee the same heading.
not the same thing, even ignoring the shape of the Earth.
That's because as the location of magnetic north is not at the top of the globe, so as we move around, even with the same country, the compass will show different readings for the same direction. (it is slight, but it does change)
So if you start in, say Southern California and fly to Oregon in a straight line, you won't be on the same heading the whole way, because the magnetic deviation changes along the route.
Now, for what you might think of as very short flights, say 100 miles or less, it is possible to fly in a straight line, and have that bee the same heading.
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I apologise for confusing Lt Peter Puget with Miss Dorothy Paget, although Miss Paget was the more American.
I also wish to correct a major navigational error in my narrative. We coasted out over Nunivak Island not Kodiak, heading West.
I thank ExXB for his link but my flight went way north of that route, hence my remarks about bear country.
My real complaint as a piece of SLF is that the maps in the in flight magazine should show a more accurate representation of the likely flight path.
I also wish to correct a major navigational error in my narrative. We coasted out over Nunivak Island not Kodiak, heading West.
I thank ExXB for his link but my flight went way north of that route, hence my remarks about bear country.
My real complaint as a piece of SLF is that the maps in the in flight magazine should show a more accurate representation of the likely flight path.
Last edited by Pom Pax; 20th Feb 2015 at 16:59. Reason: Had not finished
I once flew from Peoria to Moline Illinois and as I remember we went from takeoff directly to final. Also takeoff from 25R at LAX points you straight at Honolulu.
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PomPax, there is no way in flight magazines can show anything other than a basic representation of a route between two points on flights longer than a few miles. As I indicated in earlier posts, on long haul flights a minimum time track is usually followed and that can vary from day to day.
To give you an example I regularly fly from London to Houston. The routing can vary a great deal. From Heathrow over southern Ireland, leaving the coast around Galway then arriving on the North American continent over northern Labrador, down over Green Bay in Wisconsin, then over St Louis and into Houston. An alternative is out over Liverpool, Belfast, south of Iceland, just over the southern tip of Greenland, then Labrador, New Brunswick, Pennsylvania, Kentucky,Tennessee and northern Louisiana into Houston. A third is over Glasgow, Iceland, central Greenland, Hudson Bay, Chicago, St Louis and into Houston. In the summer you can go out over central Ireland, Gander, just west of Boston then west of New York, Washington DC, over Georgia and across to Houston. There are other variations and the reverse journey can also be as variable. The only constants are the departure and arrival points and the flight number.
Shorter flights in Europe are often to a standard routing but will vary for weather, time of day and traffic. Manchester to Amsterdam and vice versa is usually over Hull then direct to the Dutch coast just outside Amsterdam. From time to time, in either direction, I've flown over central Lincolnshire with the UK entry/exit point being just north of Kings Lynn.
Stansted to Shannon and vice versa is normally over Dublin and Wallasey but if traffic in the London area is light a routing over Bristol and south of Wexford is used.
By the way, there are dozens of flights by western airlines over Russia every day. Treat yourself to a flight tracking program.
To give you an example I regularly fly from London to Houston. The routing can vary a great deal. From Heathrow over southern Ireland, leaving the coast around Galway then arriving on the North American continent over northern Labrador, down over Green Bay in Wisconsin, then over St Louis and into Houston. An alternative is out over Liverpool, Belfast, south of Iceland, just over the southern tip of Greenland, then Labrador, New Brunswick, Pennsylvania, Kentucky,Tennessee and northern Louisiana into Houston. A third is over Glasgow, Iceland, central Greenland, Hudson Bay, Chicago, St Louis and into Houston. In the summer you can go out over central Ireland, Gander, just west of Boston then west of New York, Washington DC, over Georgia and across to Houston. There are other variations and the reverse journey can also be as variable. The only constants are the departure and arrival points and the flight number.
Shorter flights in Europe are often to a standard routing but will vary for weather, time of day and traffic. Manchester to Amsterdam and vice versa is usually over Hull then direct to the Dutch coast just outside Amsterdam. From time to time, in either direction, I've flown over central Lincolnshire with the UK entry/exit point being just north of Kings Lynn.
Stansted to Shannon and vice versa is normally over Dublin and Wallasey but if traffic in the London area is light a routing over Bristol and south of Wexford is used.
By the way, there are dozens of flights by western airlines over Russia every day. Treat yourself to a flight tracking program.
Last edited by philbky; 20th Feb 2015 at 18:46. Reason: Additional info
PomPax, there is no way in flight magazines can show anything other than a basic representation of a route between two points on flights longer than a few miles.
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I understand that the mapping companies who provide the maps for the inflight magazine, websites and IFE have constant battle to try and retain ANY resemblance to the real world below
the airlines want it as simple (and cheap) as possible
the airlines want it as simple (and cheap) as possible
I understand that the mapping companies who provide the maps for the inflight magazine, websites and IFE have constant battle to try and retain ANY resemblance to the real world below
