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- Hacker News
- I like stop overs but I wish they counted toward flying time.by bilsbie
- 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?
by netsharc - 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.
by r2sk5t - Or just… computer controlled air vents?by lazide
- I think once bleed air is compressed to a suitable pressure it's hotter than room temperature, and has to be cooled down.by inigyou
- Maybe the refrigeration is shared with the galley (food storage), and/or is only needed when the plane is on the ground?by gosub100
- Seems like the galley air cooling system is designed for cooling the equipment and food in the galley, not the general air supply for the passengers.
https://aviateai.com/efficient-galley-cooling-system-optimiz...
by tecleandor - > flight times of up to 22 hours
Making flight connections is never fun, but this sounds absolutely brutal.
by beaviskhan - Does it actually take 22 hours for a commercial airplane to get to the diametrically opposite point on the globe?by zahlman
- 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.by u1hcw9nx
- 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.
- 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.by darknavi
- 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.by wildzzz
- 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.by toast0
- 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"
by Scoundreller - 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.by EspadaV9