I hope someone is writing some code that'll automatically integrate winds aloft forecasts into flight plans!
The fuel savings (and time in the air) ROI across the entire air travel industry would by yuuuuge, and the only cost is development time (I say "only" as you're not having to build any new physical machinery).
Every airline does this. A fuel estimation program I re-wrote in 1991 or so had a whole bunch of tables and formulas related to correcting for the effect of the jetstream on fuel estimates, you'd have to do this otherwise when you're going against the jetstream you're going to simply run out of fuel before you reach your primary.
United gained a fleet of long-range 757s from the merger with Continental Airlines. These are smaller planes (but ETOPS certified) with smaller crews, which is good for United's bottom line.
757s can make it across the Atlantic, as long as conditions are good and there are easy winds.
On the westbound return flights, and this happens more than United will care to admit, the headwinds can be too strong and the flight needs to refuel in Goose Bay before continuing to the United States.
This typically adds an unexpected 90 minutes to the flight, which can really screw you up if you're trying to clear immigration and make your connecting flight. You usually don't learn of this fate until you arrive at the terminal for boarding.
Goose Bay in Labrador and Gander in Newfoundland are the old refueling stations between the US and Europe (originally Shannon Ireland). They're still capable of handling large jets so they're typically the landing spots if there are fuel or other issues such as medical emergencies with planes flying over the North Atlantic.
I am not following you. Why is visiting Goose Bay relevant? Going over Greenland is usually part of the Great Circle route used between the East Coast in the US and UK/EU but I'm not familiar with Goose Bay.
Another reply in thread explained it. Goose Bay is the United refueling destination when unexpectedly strong headwinds prevent a continuous flight to the US.
Fascinating. I had no idea. I'm surprised they don't use Gander International in Newfoundland. This used to be where nearly all trans-atlantic flights refueled before the arrival of the "jet age." Its a pretty important place still. In fact Gandar is still responsible for all air traffic control over the Western North Atlantic airspace. In fact your plane talks to them until it switches over to Shannon on the West coast of Ireland.
I've heard there's a cocktail lounge there and the pictures on wall of the visitors that passed through Gander are a cultural "who's who" of the 20th century - everyone from the Beatles, to Nehru, Kennedy, Elvis, Castro, Garbo etc, have their pictures on the wall. You basically had to pass through Gander to take a transatlantic flight.
Depending on the time of year the flights from SFO to HKG will fly north along the coast to Alaska, then over to Siberia and down the Asia coast. This is a 15hr+ flight to avoid the Jet Stream. The flight back is 4+ hours shorter!
Keep in mind the route you described is basically the great circle route so it's the route you would take in no winds. http://www.gcmap.com/mapui?P=sfo+-+hkg
Alaska and Siberia are still a bit off from the SFO-HKG great circle route. From closest point there is about 1500 km to the Siberian mainland (unless you count Kamchatka as Siberia, and even that is still some 500 km off so you don't really come "over" Siberia.).
But yes, it wouldn't be that much a detour to go nearer Alaska and over Kamchatka.
Computing fuel cost of a specific route is not the same as finding an optimal route. Route finding in the jetstream is like a continuous and constantly changing traveling salesman problem in 3D.
Right. I stand corrected. It could be thought of as a vector space of wind velocities. Simple gradient decent would not yield optimal solutions in many cases.
I wonder if the jetstream is constant enough to consider it as a static field for the flight duration. Probably not. Wind likes to change.
Airline flight path scheduling is a complicated process where wind and weather patterns are only one aspect of the route taken. Most trans atlantic and trans pacific routes operates with well known "highways" that are strictly adhered to. Apart from weather/wind, load factors, crew certification, craft certification, traffic congestion are some of the factors that existing automated flight route programs already factor. There is a youtube documentary that details the flight scheduling process. Additionally, for the more interested airliners.net's forums has a large trove of information talking about the same topic.
I'm stunned that they don't do that already. They've had specialized weather codes that give more accurate jet stream forecasts for a couple of decades now...
We mainly get data from where planes and weather balloons travel -- there's no way to get detailed data about the entire volume of the atmosphere (although it's being worked on.)
As a result, models get initialized by the output of previous models, and the main thing that keeps them somewhat close to reality is the data we collect on the surface.
Also, since a plane flight takes several hours, you really need a prediction to pick the correct path, not just the data right now.
Back in the 1930s the rigid airships plying the Atlantic used 'pressure ridge' techniques.
During the flight the navigator would use the later weather reports to plot a course that would follow the ridges between high- and low-pressure regions, either to find a corridor of minimal wind or to ride a favorable wind like a slingshot. Without that, they couldn't hope to reach the other side if they hit a headwind.
I wish I could remember more but the only reference I've found to it is in an old library copy of 'Giants in the Sky' by Douglas Robinson.
AICs flight planning software (Sabre Flight Plan Manager) has had this capability for ages. This was simply a regulatory restriction for them that was also mapped inside the software.
I was under the impression that carriers and captains have taken the jetstreams into account when planning their routes for decades and it is systematic.
Cabin announcements have mentioned this already in 1990's: "Ladies and gentlemen, our flight path takes us today further to the north so we'll be passing Vorkuta and approach the Lake Baikal from north before entering Mongolian airspace. This way we can utilize tailwinds and our estimated time of arrival in Beijing is about half an hour ahead of the schedule."
Yes, "Air India made the change after receiving approval from India’s Director General of Civil Aviation to operate on the NOPAC and PACOTS tracks that cross the Pacific Ocean."
I don't know why, and even though the net effect is the same, I think it's really cool that instead of going back and forth, like most flights, this plane (and its passengers) keeps going in the same direction and goes once around the earth on each "return" flight.
Then why other operators are not doing this long-haul nonstop route? This flight plan has been proven successful for Air India, they run it thrice a week at 88% occupancy. Now, they'll be flying this route daily[1].
Air India DEL to SFO nonstop flight was launched in December 2015[1]. So, it's a relatively new route for Air India, and it has been very successful due to its non-stop nature. This change in route (flying over Pacific) was announced back in August 2016[2] itself. They're doing incremental optimization of route plan, nothing wrong in it. There might be permits/permissions required to fly over Chinese air space too, which might have been resolved by now[3].
I dont think there is any greater lesson or theme here about lost chance of BRICS of anything. I think the world is ever changing and there is always newer opportunities that show up to capitalize from.
India is a big country/ship and is harder to steer quickly. In the last 25 yrs, India's GDP growth rate has not fallen much below 4% (averaging more than 6%). India is achieving near 100% literacy rate below a certain age demographic, it has a good space program, there is good encouragement for education and free enterprise, I reckon India is doing many things right.
Additionally, most of the stress on an aircraft is from pressurisation/depressurisation. So most flights cause similar amounts of wear on the aircraft regardless of flight time.
Kudos for ingenuity but from my understanding, flying over land is preferred than over an ocean as there are options available in case of emergency. So isn't this jeopardizing flights for fuel savings?
Land routes also tends to have certain hazards that generally don't exist in the open sea, such as 8km+ mountains, idiots with missiles, and much busier air corridors around major cities. That might balance out the risk of an ocean crossing.
Just came back to look at this, and saw that parent had basically replaced his original comment with a new one. The original parent said that all over-water flights were within gliding range of an emergency airport at all times -- this is obviously not true, which was what I was pointing out.
Given modern aircraft design, flying over open water makes good sense.
Yes, but flying within the gliding distance of emergency airports is acceptable (unless of course there is an emergency during early stages of climb or late stages of descent).
Nope. ETOPS allows planes to operate up to 180 minutes away from an emergency landing field, almost 10x the world-record glide distance quoted in this article.
Multi-engine failures on a twin engine aircraft are the rarest of the rare events and so far there have been less than a handful such events in record and as such, in my comment I assumed that gliding would imply a single engine failure as is implied by ETOPS which you failed to note.
The quoted flight as a result of a massive fuel leak and ignorance on the captain's part to notice fuel imbalance led to dual engine failure.
Also, ETOPS itself has multiple ratings and the A330-200 (in the quoted flight) was certified for ETOPS120 or 120 minutes away from an emergency field on the flight plan and not 180. The new 300+ series rated with ETOPS180 and beyond have a higher composite content to reduce weight and perhaps more fuel efficient engines (ETOPS implies single engine failure).
This being a post about airliners crossing oceans, and ETOPS being thrown about - you'd expect people would know.
Without any power, airliners can't really glide much. Of the few cases of all-out engine failures, even fewer make it safely to land or water - most of which that did were at their cruising altitude at the time of failure. With only memorable exception being the hudson river ditch.
In-fact, during the landing or take-off, even a single engine failure can catch the crew off guard and is among the worst case scenarios pilots are "trained" for.
Doesn't this sort-of imply that they could do the same thing the other way also? Or are they already doing that by catching the polar jetstream at the top of the polar route?
I was on a BOS-LHR flight once that picked up a good tailwind and we arrived well ahead of schedule, only to sit in a holding pattern for 30-ish minutes so we could land after the airport noise restrictions were loosened at 6am.
Super frustrating to fly over your house repeatedly when all you want to do is get home!
I fly SFO-LHR often. Sometimes the flights do actually take a southerly route (overflying New York) to take advantage of the wind. It's all a tradeoff of increased distance vs increased speed, depending on wind patterns on that day.
The airplane works by pushing the air and gets a speed relative to the air. If the air is moving, the ground speed will need that speed added.
Ignoring the airplane pushing the air, an airplane can be pushed by wind too.
An airplane on the ground would not be pushed by air, because of friction. If you somehow managed to make an airplane float (without using the engines), this is no longer a factor; quite the reverse. The airplane will be dragged along by the air. "big things can't be pushed by air" is ground-logic, due to friction against the ground.
Not a physicist, but if a plane is flying by 900 km/h compared to the air, and the air is moving by 100 km/h relative to Earth, it can make the plane fly 800 or 1000 km/h relative to Earth, can't it?
No trolling, It seems to me the airplane does not have enough surface area (sail) to be pushed by the wind.
My final conclusion is relative movement, the jet stream is moving at speed X vs the ground and the airplane at speed Y vs the surrounding wind, the airplane moves then at speed X+Y vs the ground.
My question is now, a GPS based speedometer will read X+Y speed. A wind based one will read just X.
I should have asked if the airplane is moving faster vs the surrounding wind.
15+ hours in the air. In economy. That isn't healthy. I'm wondering if we eventually get to the point that health agencies speak up, that there is too much risk in having people sit in tiny chairs for such periods.
When I was a kid I did lots of 8+ hour flights (YVR-London, London-middle east). Seats were bigger then. Now I see old people sitting in tiny seats and wonder how many will leave the flight with a DVT injury? How many will be in hospital with flu the next day? If sitting is the new smoking, these flights are like sleeping inside a chimney.
People have spoken with their wallets. The legacy carriers that traditionally had larger seats and more varied classes of service were eaten alive by budget carriers on Price.
I've never in my life seen a human-sized seat in Coach (in terms of width). I'd love to speak with my wallet for 2x2 seating on narrowbodies, but the asking price isn't reasonable -- typically 5x the price for business class, for less than double the space.
I still can't believe we don't have a "get your own armrest class" option with minimal additional legroom for (say) 50-75% extra cost.
Orders of magnitude increases in cost will never be acceptable to the average person, or even the spending-their-own-money 5%.
I travel for a profitable business, and there's no way in hell they're paying 5x extra for us plebes to have a little extra comfort. I imagine only executives and the consultant class get away with it.
I find Delta's Comfort+, Virgin's Premium Economy, and JetBlue's EvenMoreSpace to be quite a good compromise of price vs space. None are "private arm rest", but all are quite good fore and aft and my weight in lbs nearly overflows a uint8 and I'm comfortable side-to-side.
Comfort+ seems to be $99/way on trans-Atlantic and JetBlue's are $30-60 per leg on most flights.
I'm a (low) executive who probably could fly business class more (in the sense that our travel policy doesn't prevent it), but I choose not to as it's not a good use of shareholder funds. I only do it if it's <~$200 more or if I'm flying and going directly from the airport into a critical meeting. Routine travel and I'm fine in coach.
Can confirm, Delta's Comfort+ is "good enough" and depending on the aircraft United's EconomyPlus can be good enough, although I feel really sorry for the people who pay extra for EconomyPlus on those ERJ's. LOL. What a rip off.
6'5" @ 230 EconomyPlus on an ERJ gets you access to the bulkhead rows. Just wrapped 40 weeks of IAH-DSM on ancient ERJ's still sporting Continental cabin parts.
Yeah, have absolutely no need for a lie flat bed. Just "your own armrest" which I haven't really seen on many carriers, at least not domestic. I'm trying to swing Premium Economy on Lufthansa which looks nice, except I made the mistake of booking through United, so neither airline will take my money for an upgrade. sigh. Air NZ also has a good premium economy. That's all I ask. Sadly most domestic carriers only offer more legroom, which I don't much care about.
I have done SFO-DEL 3 times in last 6 months and on all 6 journeys, the plane was completely full - only one or two seats empty in economy. Half of the in-seat entertainment was broken (bad remotes/hung screens/broken USB ports) still people preferred a 15 hour journey over a connection, so I can attest to this first-hand
> Now I see old people sitting in tiny seats and wonder how many will leave the flight with a DVT injury?
I think especially old people should already know to wear compression socks when sitting for long times. And the airlines AFAIK also hint people to use them, even for short flights.
In fact Air India is one of the most generous in terms of legroom and seat width (An artefact of it being a govt owned entity). They have been slow to adopt the 10 seat across(in Y) that has become standard with the 777. Try flying in EK or UA and see the difference. Trading seat comfort to entertainment choice (among other factors) is an individual choice.
I regularly fly this route and also SFO<->NYC every other week, and often in economy as a result of last minute bookings.
You have some big claims without any backing. As from my experience, the only issue is fatigue and discomfort through the flight. Air India actually has some really good seat pitch on the 773s
I do multiple 12/13 hour flights per year. It's not a big deal once you get used to it. The hardest part is just preparing yourself to be able to shut down properly. We spend too much time constantly stimulated that sitting still for a while freaks people out.
I find there is a benefit to being alone with your thoughts for half a day or so, in a physically inactive state. How many people honestly ever spend that time 'switched off'.
It's all in how you approach it really, glass half full/empty
What is your suggested alternative.. force every plane to land half way and take a coffee break? Also, aren't they the same planes and seats as decades ago? We don't replace planes very often, neither do they just sneak in another seat on every row.
That's a comparison of various classes and other types of seating, not the same seats from some time ago.
EDIT: From within the article,
Early jet planes like Boeing's 707 had 17-inch seats, a dimension based on the width of a U.S. Air Force pilot's hips, says Airbus marketing chief Chris Emerson.
That standard for long-haul flying increased to 18-inches in the 1970s and 1980s with the 747 jumbo and the first Airbus jets. It widened to 18.5 inches with the Boeing 777 in the 1990s and A380 superjumbo[1] in the 2000s. Now, cost-conscious airlines are moving to lighter 17-inch-wide seats on their Boeing 777 and 787 Dreamliners and 18-inch seats for A350s.
Boeing is saying that airlines are ordering more planes with more cramped economy seating than they were before, even though they're the same models of plane.
"For almost 20 years, the standard setup in the back of a Boeing 777 was nine seats per row. But last year, nearly 70% of its biggest version of the plane were delivered with 10-abreast seating, up from just 15% in 2010."
So over five years, airlines were ordering more and more of these especially cramped 777s than before, which means the same class and the same model of plane has narrower seats and aisles so they can cram in one extra person in each row.
This is a discussion on new planes, but I would be surprised if airlines weren't moving to the new configuration on older planes as well whenever they do an upgrade or refurbish (or use those planes on lower-demand routes where the lower capacity doesn't impact the actual number of seats sold).
> Also, aren't they the same planes and seats as decades ago?
> Early jet planes like Boeing's 707 had 17-inch seats
> Now, cost-conscious airlines are moving to lighter 17-inch-wide seats on their Boeing 777 and 787 Dreamliners and 18-inch seats for A350s.
If anything, we're just going back to the older seat width after enjoying a few extra inches on the non-low cost carriers; Sure they're adding more rows but the seats themselves are just as wide (if not more) than what they were decades ago.
The cabin is updated more often than the plane itself. Also chairs change in order to become lighter and take less space. This allows for more rows (depending on airplane model and airline)
Certifying authorities set the limits on how many people you can put on the airplane. The JAA (essentially EU version of FAA) had a limit that was (IIRC) 5 fewer than the FAA because during their testing of evacuation that was all they could get out within the time limit.
I don't think they are the same seats - they get replaced - but they are pretty much the same size. Legroom, on the other hand, has definitely decreased.
(2) The airframes aren't new. but the seating arrangements sure are. And modern tech, big-data, means far more flights are booked solid. When I was a kid flying london-vancouver it wasn't unusual to see an entire row empty. That's not a thing anymore.
When I was a kid flying london-vancouver it wasn't unusual to see an entire row empty. That's not a thing anymore.
I've been on domestic U. S. flights that have had multiple rows empty, to the point that my rough math said the airline couldn't have been making a profit on that flight. About a quarter of the time I'd get a row to myself. Those days are long gone, of course. Now I can't even get an exit row months in advance even if I want to pay for it.
Airplanes need to be moved around. Maybe one leg is partially empty because the plane needed to be somewhere for a D check.
When I was a dispatcher for a very small regional carrier, we might cancel a flight that was too empty. More often we'd have to fly a nearly empty or empty flight so that the plane would be where it needed to be for the next day.
As for (2), exactly. Even at the start of the millennium I'd fly LAX-Melbourne and often the Sydney-Melbourne leg was a 747 with a dozen passengers on it (because there was also a non-stop that would routinely be half full).
This year I got the full row (3+4+3 seats I think?) in SFO->FRA. I was not the only one, basically everyone near me had a row each. at least a segment of a row each.
I didn't really go to the center row though; I was more comfortable resting on the window and keeping my legs on the seats -- can use a laptop comfortably, and also sleep.
Many airlines offer a Premium Economy product which offers wide seats and more legroom (think domestic First Class). They don't tend to sell well; Turkish Airlines is in fact removing them from their aircraft [0] — and many major airlines don't even have a Premium Economy cabin (United, Delta, Emirates, Etihad, Qatar, et al).
Most people just aren't willing to pay for wider, more spacious seats.
The fuel savings (and time in the air) ROI across the entire air travel industry would by yuuuuge, and the only cost is development time (I say "only" as you're not having to build any new physical machinery).
EDIT: Boeing already offers this service it appears: http://www.boeing.com/commercial/aeromagazine/articles/2011_... and the fuel savings are substantial.