Living in Australia, and travelling to Europe last Christmas as a family of 4, I really wanted to get the direct London to Perth flight, but connecting flights didn't line up. Being able to do Melbourne or Sydney would be great. Not needing to deal with connections, and cutting 6+ hours off the total travel time sounds amazing, possibly getting us there a day earlier, meaning more time for Greggs vegan sausage rolls.
Also bad for fuel economy (and/or take a hit on cargo/pax/luggage carrying capacity): You have to take off with all that fuel even though you only need X / hr. Increased weight = more flying at a lower altitude (+ air resistance) until the fuel burn makes it safe to fly higher.
On shorter flights, you still have the weight impact from that empty tank and its infra. If they had to make a bump out on the fuselage, you have a permanent aerodynamics hit.
It's like permanently attaching a cargo carrier to your vehicle to carry more fuel. Fewer fuel stops, but more burn per mile. Can make sense in some situations.
The study of breaking up long-haul flights for reduced fuel burn is usually called: "Intermediate Stop Operations"
A compromise option is a technical stop[0] where the plane lands to refuel but passengers don't have to transfer to another aircraft (and often don't even have to deplane). I've never experienced one of these but it sounds way less annoying/stress-inducing than a connecting flight.
Not only do take-offs spend large amounts of fuel; the fact of a landing and the servicing and refueling in the airport also cost the airlines.
Not having to land but instead having to carry some extra fuel while the engines work in their most efficient mode, and the air drag is low at a high altitude, should make airlines money. Else they won't try that :)
It's basically the business model for some airlines like the Icelandic and middle eastern ones. Hub in the middle so you're not paying (potentially extra) staff to rest on an aircraft and/or hotels at each end. Be at home more rather than an out-station. Fuel up more where its cheaper. Do some "scissor" routing. Fly cheaper/less specialized aircraft. Not as easy for Qantas to get all those advantages. Cargo airlines do the same to carry more cargo.
It's okay that different businesses specialise differently. Icelandic Air can do the two short hops and Qantas can focus on the super long nonstop routes, they're both valid.
But it may allow operation of more routes without the need to refuel at both ends. That can be logistically interesting, paticularly going forward in a world of fuel crisis and uncertainty. Being able to deliver people in and out of Cuba without having to refuel in that country would be a market niche.
Assuming you can regularly land with your fuel tanks half-full. You could overbuild everything to support that, but usually airlines don't want to pay for a niche design to support that. I'd bet military aircraft do get that treatment though.
It is actually rather common. Many airlines running shorter flights will not refuel at every stop. It saves time on the ground, which can be more valuable then fuel.
New A350's has better air quality, higher humidity and cabin pressure, and these long haul flits have less seats to reduce weight .. but it's still brutal.
22 hours is a very long time to be in a plane. But, being able to skip a stop in a 3rd nation is likely worthwhile for many. Depending on the routes, it will likely reduce the overall travel time significantly and a meaningful amount of time in the air.
Seattle to Joburg is brutal. It's ~23 hours of flying with a lay over somewhere like Dubai. As much as a 23 hour flight sounds terrible, it's hard for me to express how much dread I felt getting back onto a plane right after a 13 hour flight. I'd rather just hunker down for the full day I think.
I'd love to visit Australia and SE Asia but am hesitant with those long flights. I'd probably be fine with layflat seats but those are well beyond what I'd ever consider paying for an airline ticket.
I've traveled UK to Australia a few times. Not nonstop, but with stops in SE Asia, basically 2x13 hours plus a few hours airport time.
It sucks, but you get over it because how else are you going to get there? If you don't suffer blood clots or something, it isn't really actively dangerous.
Many of colleagues do this all the time, usually via the Middle East. I did it before; it sucks but with enough gin tonic and melatonin it goes by in with too much pain.
You just know this is going to be 2-3 times the price of an economy seat, which means you're going to buy the economy seat anyway. In flights, price beats everything else.
You could pack a lot more in if you sedate them and put them in racks like they have at the morgue. TBH I'd sign up for that on a long flight if the sedative recovery wasn't bad.
What are the economics of connecting flights? I'd imagine that max flight time isn't the only factor; hubs allow people to move around via connecting flights in a way that might not be economically acceptable if all flights were direct.
These ultralong flights will surely only be used regularly on routes with enough traffic, like London/Sydney.
Although they could also run intermittently to different places. Like London/Sydney on Monday, London/Melbourne on Tuesday... Which one brings in more money? I really have no idea. If you do it like this you can serve more people with direct flights, but they can't pick any day they want. I was once on a scenic long-distance train for some reason that didn't run every day due to low usage — Wellington to Auckland, I think? Normally you'd fly.
The Sydney / London flight most direct path cross Russia and that's already 17000km so probably it has to go south of Iran and that's another 1000km thus 18000km total.
The route Qantas has stated they will use (at least for part of the year due to weather and winds) actually goes northeast over the Pacific Ocean, over the central US/Canada, over the North Pole, and then into the UK from the north. It doesn’t go over Asia at all.
> In addition, a new galley air cooling system will also be certified, which features lighter and more efficient refrigeration units for very long flights.
I wonder how they work.. considering outside air is way below freezing ar cruising altitude, I guess radiators?
Could the refrigerant be brought close to the plane's skin to cool it?
You could quickly flip it open with a servo when braking, controlled by a
differential thermostat so it only pulls in air when the outside isn't too much hotter than inside. I think you actually want a negative thermostat offset, because even if it's a couple degrees warmer you still get moving air.
Compared to rolling down the window you don't get the loud buffeting sound, it acts as a really good aero-brake, and it pulls in huge amounts of air. There's the downside that it will preferentially pull in air around intersections, where traffic pollution tends to peak due to braking and accelerating (EVs help but there's still brake and tire dust).
Love this honestly. It has definite "shitty project" potential...
Planes generally avoid braking. Many are equipped with explicit "speed brakes" and all can use their control surfaces to create inefficient aerodynamic configurations, but fuel is expensive so they avoid it unless there's a situation like getting cleared for a shorter approach than expected. Ordinarily, they plan a descent path which can be accomplished naturally with a lower than normal thrust. The standard is three degrees below horizontal. Of course they also activate all braking possibilities upon touching down, but you can't keep the fridge cold by cooling it only upon landing.
When cruising (most of the flight), smooth aerodynamics are extremely important, and you wouldn't mess them up just to keep the galley fridge cold. Example: whenever a plane has the landing gear out it burns 2-3 times as much fuel, because that's just how much it costs to not be smooth. That's why they retract the landing gear almost the moment the plane leaves the ground, and why a plane with its landing gear stuck has to return home (despite not being a serious emergency).
At altitude you can reject heat straight to the aircraft skin. Some designs run an internal heat sink on the ground and during climb, watch altitude, and only switch on the skin-exchanger coolant pump once outside is cold enough to cool the loop for free.
The reason it stays a refrigeration unit and not just vents is the ground case. Gate on a hot day, doors open, no ram air, warm soak: that's the worst case, and where the compressor has to work. One published point-of-use chiller design specs roughly double the load on the ground vs in cruise (order of 700 W vs 300 to 400 W per unit). So the vapor cycle is sized for the ground, and most of a 20 hour flight is spent in the regime where you barely need it.
And these aren't fridge boxes at each cart. It's a central vapor-cycle chiller cooling a glycol/water loop piped to air chillers at the galleys; the carts get chilled air. The heat comes off the condenser and goes to ram air, a skin exchanger, the cargo hold, or back into the ECS, depending on the aircraft. Which one the new ULR units use, Airbus hasn't said. For a 22 hour flight the interesting number isn't peak capacity, it's efficiency and weight in cruise, which is probably what "lighter and more efficient for very long flights" is pointing at.
Was once on a flight sitting at a gate with a faulty ground air connection or something, and they weren't allowed to run the APU at the gate due to pollution. It must've been 40 degrees (Celsius) inside, at Singapore Changi, and they were delayed at the gate too. Everyone breathed a sigh of relief when we started moving and got air conditioning from the engines.
Making flight connections is never fun, but this sounds absolutely brutal.
On shorter flights, you still have the weight impact from that empty tank and its infra. If they had to make a bump out on the fuselage, you have a permanent aerodynamics hit.
It's like permanently attaching a cargo carrier to your vehicle to carry more fuel. Fewer fuel stops, but more burn per mile. Can make sense in some situations.
The study of breaking up long-haul flights for reduced fuel burn is usually called: "Intermediate Stop Operations"
[0]: https://travel.stackexchange.com/q/1598
Not having to land but instead having to carry some extra fuel while the engines work in their most efficient mode, and the air drag is low at a high altitude, should make airlines money. Else they won't try that :)
So even if you only care about carbon emissions, it can still make sense to skip the stop even if it causes slightly more total fuel burn.
It sucks, but you get over it because how else are you going to get there? If you don't suffer blood clots or something, it isn't really actively dangerous.
That sounds like pure torture
https://www.airnewzealand.com/economy-skynest
Although they could also run intermittently to different places. Like London/Sydney on Monday, London/Melbourne on Tuesday... Which one brings in more money? I really have no idea. If you do it like this you can serve more people with direct flights, but they can't pick any day they want. I was once on a scenic long-distance train for some reason that didn't run every day due to low usage — Wellington to Auckland, I think? Normally you'd fly.
I wonder how they work.. considering outside air is way below freezing ar cruising altitude, I guess radiators?
Could the refrigerant be brought close to the plane's skin to cool it?
https://aviateai.com/efficient-galley-cooling-system-optimiz...
In my dreams, my ultra-advanced car would open the windows when braking to get two benefits in one.
https://www.fastlanecars.com/blog/wing-windows-history-and-c...
https://www.ccjdigital.com/trucks/article/15749837/the-story...
You could quickly flip it open with a servo when braking, controlled by a differential thermostat so it only pulls in air when the outside isn't too much hotter than inside. I think you actually want a negative thermostat offset, because even if it's a couple degrees warmer you still get moving air.
Compared to rolling down the window you don't get the loud buffeting sound, it acts as a really good aero-brake, and it pulls in huge amounts of air. There's the downside that it will preferentially pull in air around intersections, where traffic pollution tends to peak due to braking and accelerating (EVs help but there's still brake and tire dust).
Love this honestly. It has definite "shitty project" potential...
When cruising (most of the flight), smooth aerodynamics are extremely important, and you wouldn't mess them up just to keep the galley fridge cold. Example: whenever a plane has the landing gear out it burns 2-3 times as much fuel, because that's just how much it costs to not be smooth. That's why they retract the landing gear almost the moment the plane leaves the ground, and why a plane with its landing gear stuck has to return home (despite not being a serious emergency).
The reason it stays a refrigeration unit and not just vents is the ground case. Gate on a hot day, doors open, no ram air, warm soak: that's the worst case, and where the compressor has to work. One published point-of-use chiller design specs roughly double the load on the ground vs in cruise (order of 700 W vs 300 to 400 W per unit). So the vapor cycle is sized for the ground, and most of a 20 hour flight is spent in the regime where you barely need it.
And these aren't fridge boxes at each cart. It's a central vapor-cycle chiller cooling a glycol/water loop piped to air chillers at the galleys; the carts get chilled air. The heat comes off the condenser and goes to ram air, a skin exchanger, the cargo hold, or back into the ECS, depending on the aircraft. Which one the new ULR units use, Airbus hasn't said. For a 22 hour flight the interesting number isn't peak capacity, it's efficiency and weight in cruise, which is probably what "lighter and more efficient for very long flights" is pointing at.
There are a lot of commas.
> Gate on a hot day, doors open, no ram air, warm soak: that's the worst case, and where the compressor has to work.