[AATW]

I think you mean that there is technology to get your coordinate position. Actually physically measuring distances over long distances is a lot harder.

And how, pray tell, do you think that technically works if it doesn’t know where all those coordinate positions are and how far apart they are? Your claims are getting increasingly ridiculous.

[RonJ]

The only reliable distance measurement method is an odometer, and people haven't measured large portions of the earth with it.

Incorrect. The technology is there today to make accurate distance measurements even in the middle of the worlds oceans.

I think you mean that there is technology to get your coordinate position. Actually physically measuring distances over long distances is a lot harder.

There are other technologies I’ve seen used on military ships (I can’t discuss) that can be used to measure the physical distances of the underlying land in the world’s oceans.  It doesn’t matter much to anyone because GPS is available, and it’s been shown that the two methods of measurement correlate exactly.  These days all you really need are the coordinates of two points on the earth and an accurate distance measurement can be determined.     
   

[stack]

There are winds which travel both Eastwards and Westwards in both the North and the South. There is no such thing as not taking advantage of any winds for a control flight. The planes always try to take advantage of the winds when they fly. When traveling from New York to Europe the planes fly North along the track and when they fly from Europe to New York they fly over a thousand miles south to take advantage of the opposite winds.

I'm not sure where you got that notion, but it's absolutely incorrect. In reality, it's literally the exact opposite of what you claim. Or, apparently, BA did not get your memo. Here is a BA flight from JFK (NY) to LHR (London):



Here is a return flight from LHR (London) to JFK (NY):



Bottom line, East to West. Top line, West to East. The exact opposite of what you claim:

[Tom Bishop]

There are winds which travel both Eastwards and Westwards in both the North and the South. There is no such thing as not taking advantage of any winds for a control flight. The planes always try to take advantage of the winds when they fly. When traveling from New York to Europe the planes fly North along the track and when they fly from Europe to New York they fly over a thousand miles south to take advantage of the opposite winds.

(my bold); Why do you invent these things?  That, sir, is complete fabrication, and obvious to anyone who flies or watches a flight-tracking service. 

Currently; ETH552, UAE9249, PLM999, MPH6161 for example; all travelling Europe-North America, and all mixed in with West-East traffic.

Incorrect. While the winds can shift around, there is generally a separation from the West-East traffic on the return flight.

See:

https://aviation.stackexchange.com/questions/29729/why-are-westbound-transatlantic-routes-located-hundreds-of-km-away-from-eastboun

Why are westbound transatlantic routes located hundreds of km away from eastbound routes?

Looking at flights between NY and London (click to see route):

BA 185 (EGLL - KEWR)
United 941 (EGLL - KEWR)
United 16 (KEWR - EGLL)

The FlightAware anticipated routes are quite similar in both directions, but the actual routes for past flights are really remote from each other:



The two westbound routes are either 800 km north or 1,000 km south of the eastbound route (the dotted line shows the shortest path).

Why are the two westbound routes different and so remote from each other? Why this difference of about 1,800 km?

Why BA 185 route seems to be composed of two arcs?

Did the pilots changed their mind in flight because of the jet streams? Is it related to ETOPS constraints, or alternate airport at Santa Maria? or something else?

Top Answer from the thread:

The reason this is done is due to the winds aloft. The Jet Stream is a powerful current of air that blows in a west to east direction. Airplanes crossing the Atlantic from west to east take advantage of the jet stream to get there faster and save fuel, so a course is chosen to stay in the stream as much as possible. Airplanes going from east to west will be slowed by the jet stream, using more fuel and taking longer to get across, so a course is chosen to avoid the strongest winds.

The difference can be very significant, I've been on flights from NYC to London which take 6h 30m, and ones from London to NYC that take almost 9 hours.

We can clearly see that the return flights on those routes do not follow the same path.

Bottom line, East to West. Top line, West to East. The exact opposite of what you claim:

What were the winds like on that day? Flights regularly optimize their routes on a daily basis, even multiple times a day, depending on conditions. In the graphic I provided above there was one plane which took a far +800km northern route from London to NYC and another plane which took a southern route over 1000 km below the middle route. The routes are clearly not overlapping. They are finding a route optimal for the journey and veer significantly away from the East-West traffic, and can span hundreds of km southward.

[stack]

Bottom line, East to West. Top line, West to East. The exact opposite of what you claim:

What were the winds like on that day? Flights regularly optimize their routes on a daily basis. In the graphic I provided above there was one plane which took a far +800km northern route from London to NYC and another plane which took a southern route over 1000 km below the middle route. The routes are clearly not overlapping. They are finding a route optimal for the journey and veer significantly away from the East-West traffic, and can span hundreds of km southward.

I don't know what the winds were like that day. Sure, they can divert from a typical great circle due to winds, traffic too. You said, "When traveling from New York to Europe the planes fly North along the track and when they fly from Europe to New York they fly over a thousand miles south to take advantage of the opposite winds."

They can do that due to the aforementioned headwind issue, but you make it seem like that's the only way they can fly, which is not true.

You also said, "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." How is this true when flights from say LHR to JFK avoid jetstreams, so they are obviously able to fly long distances without a jetstream?

I guess, what's the point you are trying to make? That planes flying from JFK to LHR take advantage of the jetstream and flights from LHR to JFK try to avoid the jetstream? I would agree with that. It makes sense.

[Tom Bishop]

I don't know what the winds were like that day. Sure, they can divert from a typical great circle due to winds, traffic too. You said, "When traveling from New York to Europe the planes fly North along the track and when they fly from Europe to New York they fly over a thousand miles south to take advantage of the opposite winds."

They can do that due to the aforementioned headwind issue, but you make it seem like that's the only way they can fly, which is not true.

Actually the last graphic I provided shows a returning flight which did veer off significantly to the South. If you were expecting such a statement describing that planes fly significantly to the south to account for all possible wind conditions in the North which might provide a Northern path, you are mistaken. I said that planes take that longer southern way around, and they do.

The fact that two planes flying from London to NYC, with the same point of origin, can take wildly different paths to reach the same destination clearly demonstrates that the planes are flying an optimal route based on wind conditions and it is not a route primarily based on closest geometrical points. The dotted line in the image is the most optimal geometrical route for an RE and the planes fly nowhere near that. The fact is that the planes are highly reliant on the winds and there is no "control flight".

[stack]

I don't know what the winds were like that day. Sure, they can divert from a typical great circle due to winds, traffic too. You said, "When traveling from New York to Europe the planes fly North along the track and when they fly from Europe to New York they fly over a thousand miles south to take advantage of the opposite winds."

They can do that due to the aforementioned headwind issue, but you make it seem like that's the only way they can fly, which is not true.

Actually the last graphic I provided shows a returning flight which did veer off significantly to the South. If you were expecting such a statement describing that planes fly significantly to the south to account for all possible wind conditions in the North which might provide a Northern path, you are mistaken. I said that planes that that long southern way around, and they do.

The fact that two planes flying from London to NYC, with the same destination and point of origin, can take wildly different paths clearly demonstrated that the planes are flying an optimal route based on wind conditions and it is not a set path based on closest geometrical points. The fact is the planes are highly reliant on the winds and that there is no "control flight".

I guess it depends on how you define "wildly". And there are many factors in addition to wind that are accounted for in route planning and execution.

The fact of the matter is, your statement, "Most of the long distance flights typically pointed out wouldn't be possible without jet streams.", is incorrect as flights avoid jetstreams when possible on these East to west routes.

I'm not sure what you mean by "control flight". What is that?

As far as these trans-Atlantic flights, here's an explainer on the routes generally used. 80% pass through a specific northerly airspace zone:



Every day, between two and three thousand aircraft fly across the North Atlantic between Canada, the United States and Europe. Airspace across the North Atlantic is divided into six Oceanic Control Areas (or OCAs). These OCAs are controlled by Air Navigation Service Providers (ANSPs) working at different locations in different Countries.

NATS, working with the IAA (Irish Aviation Authority), is responsible for providing the air traffic control service to the Shanwick OCA. The IAA service is provided from Shannon in Ireland, and the NATS service provided from Prestwick in Scotland (hence 'Shanwick').

The Shanwick OCA is the busiest of all North Atlantic Airspace regions. It is often referred to as 'the gateway to Europe' and around 80% of all North Atlantic Air Traffic passes through it, demonstrating the strategic importance of our Prestwick Centre and UK airspace.
This visualization shows Transatlantic traffic over a 24 hour period taken from a day in August last year and shows 2,524 flights crossing the North Atlantic, of which 1,273 pass through the Shanwick OCA. At its busiest traffic can peak at 1,500 flights a day in the Summer.

[Tom Bishop]

Irrelevant. The green diverging southern path in my last image is still in the North Atlantic and moves through that area.

And no, the return flights take much longer between London and NYC. The faster NYC to London flight is only possible because of the jetstream which has the quickest winds.

If you get on the wrong plane with insufficient fuel sometimes those "nonstop" return flights even have to stop for fuel:

https://www.wsj.com/articles/SB10001424052970203436904577152974098241982

Dozens of Continental Airlines flights to the East Coast from Europe have been forced to make unexpected stops in Canada and elsewhere to take on fuel after running into unusually strong headwinds over the Atlantic Ocean.

The stops, which have caused delays and inconvenience for thousands of passengers in recent weeks, are partly the result of a decision by United Continental Holdings Inc., the world's largest airline, to use smaller jets on a growing number of long, trans-Atlantic routes.

A "control flight" is in reference the the claim that pilots know how fast they are flying because sometimes they are not flying on the fastest route. They are always using winds to reach their destination, which is why there are two paths to the same destination in the previous image I provided despite significant differences from the optimal dotted line RE geographical route.

[stack]

Irrelevant. The green diverging southern path in my last image is still in the North Atlantic.

It is at that. I still don't know what your point is.

And no, the return flights take much longer between London and NYC. The faster NYC to London flight is only possible because of the jetstream which has the quickest winds.

Yeah, we know the jestream makes east to west flights faster. So what?

Much longer? Looks about on average to be about an hour, hour and half difference - Is that "Much longer"?:




Still, you said, "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." But of course they are possible because most flights don't use and try to avoid the jetstream east to west. They are doing so without the jetstream. So I don't know why you made that statement.

Sometimes those "nonstop" flights even have to stop for fuel:

Flights Stop for Fuel
By SUSAN CAREY And ANDY PASZTOR
January 11, 2012

From your article:



It seems Continental was using 757's back in 2012 for trans-atlantic flights. So what?

Perhaps a bad choice on their part. All of the BA flights listed above use 777's...In 2021.
- The 757-200's maximum range is 3,900 nautical miles (7,220 km)
- The 777-200's maximum range is 9,420 nautical miles (17,446 km)

A "control flight" is in reference the the claim that pilots know how fast they are flying because sometimes they are flying against the fastest route. They are always using winds to reach their destination, which is why there are two paths to the same destination in the previous image I provided despite significant differences from the optimal dotted line RE geographical route.

So flight planners use the jetstream to their advantage and avoid it when it's not their advantage. So what? What's your point?

[RonJ]

Pilots always know exactly how fast over the ground they are flying.  They also know the exact distance between the two airports they are flying between.  What isn’t known is the exact optimal route they need to fly when winds are taken into consideration.  Airline companies have, or hire, flight planning personnel to design the optimal flight route.  Computers are used along with all the available wind & temperature data to plan the best route to minimize the flight times and/or fuel burn for the individual aircraft.  Once an aircraft departs conditions can change.  On a short flight the differences are insignificant.  If a flight is 15 hours long, then obviously things can change a lot while enroute.  New flight plans can be sent to the airplane and/or the pilot in command can make some alterations in the route.  An airliner flying at 40,000 feet on a 5000-mile flight would also need to fly an additional 9.5 miles more than the exact distance on the ground between the two airports.  When you add an additional 7.5 miles to the radius of the curve you will have a longer path.       

[Tom Bishop]

Yeah, we know the jestream makes east to west flights faster. So what?

Much longer? Looks about on average to be about an hour, hour and half difference - Is that "Much longer"?:

If you found recent flights between London and NYC taking under 7 hours, it is just more evidence that the particular nature of the winds and nature of the weather is to blame. The hour difference from the main jet stream route that you found is also evidence that the return winds can be going almost as fast as the main jet stream.

It is easy to find that airliners have reported the duration from London to NYC to be nine and a half hours:

https://www.prokerala.com/travel/flight-time/from-LCY/to-JFK/



Meanwhile flights from New York to London have been achieved in under five and a half hours. This is a rather significant difference.

It seems Continental was using 757's back in 2012 for trans-atlantic flights. So what?

So if your airliner is stingy and gives you the wrong plane with insufficient fuel you might find that your nonstop flight makes stops. The point again is that the planes are highly reliant on the weather to reach their destination.

Still, you said, "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." But of course they are possible because most flights don't use and try to avoid the jetstream east to west. They are doing so without the jetstream. So I don't know why you made that statement.

In these FE discussions there is heavy emphasis on flight times, and the flights pointed out are typically the fastest route in the fastest winds. They can't make the same time without the jet streams, or even the same path. If you point out any particular flight as some sort of proof you need to separate out the winds. This is another element to the assumptions.

[stack]

Yeah, we know the jestream makes east to west flights faster. So what?

Much longer? Looks about on average to be about an hour, hour and half difference - Is that "Much longer"?:

If you found recent flights between London and NYC taking under 7 hours, it is just more evidence that the particular nature of the winds and nature of the weather is to blame. It is easy to find that airliners have reported the duration from London to NYC to be 9 and a half hours:

I'm sure it happens for a multitude of reasons. It's happened to me on a long haul east to west flight. So what?

https://www.prokerala.com/travel/flight-time/from-LCY/to-JFK/

Well, your site is irrelevant because there are no non-stops between LCY and JFK currently.

Meanwhile flights from New York to London have been achieved in 5 hours and fifteen minutes. This is a rather significant difference.

Sure is fast. Obviously not the norm. Just like sometimes east to west flights are only 45 minutes slower than norm and sometimes hours slower than norm. I still don't see what point you are trying to make.

It seems Continental was using 757's back in 2012 for trans-atlantic flights. So what?

So if your airliner is stingy and gives you the wrong plane with insufficient fuel you might find that your nonstop flight makes stops. The point again is that the planes are highly reliant on the weather to reach their destination.

Sure, planes are reliant on weather. And traffic. And ATC. And Gate access. And route planning. So what? No one is disputing that wind, weather play a significant role in the airline industry.

You started out with "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." Well, it's been shown that obviously, they do. Quite often in fact. Is all this meant to be something akin to some notion you have that we don't know the distance between NYC and London? Is this the point you are trying to make?

Still, you said, "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." But of course they are possible because most flights don't use and try to avoid the jetstream east to west. They are doing so without the jetstream. So I don't know why you made that statement.

In these FE discussions there is heavy emphasis on flight times, and the flight pointed out is typically the fastest route over the fastest winds. They can't make the same time without the jet streams, or even the same path. If you point out any particular flight as some sort of proof you need to separate out the winds. This is another element to the assumptions.

Yeah, it seems that most east to west flights try to avoid the headwinds accompanying jetstreams. That doesn't mean that they don't encounter headwinds.

It's not necessarily all about flight times. You realize that fuel is the biggest cost in the industry? And that calculations are done before every flight to have the right amount of fuel for the route? Do you think the industry isn't hyper diligent about that aspect? And how do you think they calculate the fuel required for a route?

[Pete Svarrior]

Well, your site is irrelevant because there are no non-stops between LCY and JFK currently.

So, when COVID-19 led to a significant reduction of flights from LCY, did that somehow change physics? If not, pray tell, why did those flights become irrelevant?

[Tom Bishop]

You started out with "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." Well, it's been shown that obviously, they do. Quite often in fact.

Incorrect. They do not. The same flight times and flight routes are not possible for the return flight. There is a time and a path difference.

If a taxi goes directly through a city to take me to my destination and on the return trip the taxi wants to take me on a scenic route which goes around a city it is most certainly not the same route.

Well, your site is irrelevant because there are no non-stops between LCY and JFK currently.

A lot of flights are shut down right now due to Covid. This is irrelevant. Airliners have reported nine and a half hours.

Sure, planes are reliant on weather

Which inserts additional variables and requires the analyses in these discussions to know the properties of the winds.

[stack]

You started out with "Most of the long distance flights typically pointed out wouldn't be possible without jet streams." Well, it's been shown that obviously, they do. Quite often in fact.

Incorrect. They do not. The same flight times and flight routes are not possible for the return flight. There is a time and a path difference.

If a taxi goes directly through a city to take me to my destination and on the return trip the taxi wants to take me on a scenic route which goes around a city it is most certainly not the same route.

I really don’t know what you’re talking about. I never said they take the same route. Just said they don’t always route 1000 miles south like you said.

Well, your site is irrelevant because there are no non-stops between LCY and JFK currently.

A lot of flights are shut down right now due to Covid. This is irrelevant. Airliners have reported nine and a half hours.

And I agreed with you. I’ve personally been subjected to longer than average east-west trans Atlantic flights before. I still don’t know what relevance you’re trying to tease out because one way is faster than the other. That wind is involved? Yeah, I agree, wind is involved, along with other factors already mentioned.

Sure, planes are reliant on weather

Which inserts additional variables and requires the analyses in these discussions to know the properties of the winds.

Ok, so I think I see what you’re getting at. Kinda like what I mentioned before. You’re somehow using the wind thing to say that we really don’t know these distances? Even though they are logged and reported, fuel calculations are dependent on these variables, pilots need to know how far they are flying and know where they are mid flight and how far away they are from stuff and ATC needs to know and monitor all of those things as well.

[AATW]

Right.

So the OP asked where Google Maps is wrong. Pete said China. I looked that up and while he is correct it’s not really relevant to what the OP is talking about. China use a different GPS standard which means that there is an issue with Google’s data which needs some correction. But it’s not like Google think China is a completely different size of shape to reality - those are the sorts of issues the OP is talking about. Do any exist?

And then we have Tom talking about various reasons flight times may be different from average. Again, true, but irrelevant to the OP. So unusual winds may mean planes have a faster or slower ground speed than usual. Is the suggestion that planes don’t know how far or fast they’re flying and they just get there when they get there? Vaguely true in the very early days of aviation, certainly not true now and hasn’t been for decades.

The point of the OP is this, and it’s a point which has been made on here before. IF the earth is flat then it should be possible to make a map which accurately represents the entire earth. Distances between places should be accurate, land mass shapes and sizes and the relative distances between them should be accurate. Flight paths should make sense on this flat map. But none of that is true. There is no agreed FE map which accurately represents the whole earth.
There is, however, geolocation data which claims to represent a globe earth which seems to do a pretty good job of telling people where they are and how far places are apart. That data can be easily checked.

Tom agreed above that technology exists to accurately tell you your coordinates. I asked him how he thinks that technology works if the location of those coordinates and the distances between them is not known accurately. It’s notable that he ignored that and has continued his diversion about flight times.

[Gonzo]

Hi,

Air Traffic Controller from the UK here.

Using LCY - JFK flights to illustrate journey time is not ideal for a few reasons.

It used the Airbus A318 aircraft which is usually a short haul aircraft (cruising speed of around Mach 0.78 compared to 777 or 787s at Mach 0.82 etc).

The flight would fly LCY to Shannon in Ireland, where it would refuel and the passengers would disembark and clear US customs so when they’d arrive in JFK it would be as a domestic flight.

The runway length at LCY was too short to allow an A318 to depart with enough fuel to get to JFK.

The return flight from JFK to LCY was direct without stopping.

[Pete Svarrior]

Thanks for that, Gonzo, that seems to tie this loose end up nicely.

One small thing that bothers me, though - why does the plane need to refuel in Ireland for the outbound flight, but doesn't need a similar pit stop during the return flight?

[AATW]

I’m going to guess it’s because:

The runway length at LCY was too short to allow an A318 to depart with enough fuel to get to JFK.

Which wouldn’t be true at JFK.
(LCY is brilliant by the way, it’s relatively close to me and small so you can get through security quickly)

[Pete Svarrior]

Ah, yes. Apparently reading isn't my strongest suit. Personally, I'm satisfied with this explanation.