7 ms·
Rear center fuel tank adds roughly 20k liters and extends range by 1k NM
- r2sk5t 2mo ago[flagged]
- netsharc 2mo ago> 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?
- lazide 2mo agoOr just… computer controlled air vents?
- Scoundreller 2mo agomay not be worth the aero hit. Kinda like running a/c in a car at high speeds instead of opening the windows. Not sure where the crossover point is. In my dreams, my ultra-advanced car would open the windows when braking to get two benefits in one.
- schiffern 2mo ago>In my dreams, my ultra-advanced car would open the windows when braking to get two benefits in one. Or use those triangular vent windows / wing windows, as seen on old trucks and classic cars. https://www.fastlanecars.com/blog/wing-windows-history-and-classic-car-design https://www.fastlanecars.com/blog/wing-windows-history-and-c... https://www.ccjdigital.com/trucks/article/15749837/the-story-of-truck-wing-windows-the-end-of-the-traditional-truck 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...
- inigyou 2mo agoPlanes 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).
- gosub100 2mo agoMaybe the refrigeration is shared with the galley (food storage), and/or is only needed when the plane is on the ground?
- tecleandor 2mo agoSeems 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-optimizing-comfort-aboard/ https://aviateai.com/efficient-galley-cooling-system-optimiz...
- r2sk5t 2mo agoAt 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.
- AYoung010 2mo agoPresenting raw LLM output as your own writing in a human-to-human context is rude and antisocial, not to mention incredibly transparent.
- inigyou 2mo agoWas 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.
- t0mas88 2mo ago[dead]
- inigyou 2mo agoI think once bleed air is compressed to a suitable pressure it's hotter than room temperature, and has to be cooled down.
- beaviskhan 2mo ago> flight times of up to 22 hours Making flight connections is never fun, but this sounds absolutely brutal.
- wildzzz 2mo agoI'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.
- Scoundreller 2mo agoWould make sense to offer packages with lay-flat seats in shifts (possibly formally/informally for people on the same ticket).
- 27183 2mo agoYou 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.
- throwaway173738 2mo agoNext stop Phlosten Paradise.
- 27183 2mo agoThis is exactly what I was thinking of when I wrote it down ;)
- post-it 2mo agoJust like The Jaunt by Stephen King. "It's longer than you think, dad! ...about 22 hours."
- throwaway270925 2mo ago
- WinstonSmith84 2mo agoThe 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.
- cobolcomesback 2mo agoThe 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.
- u1hcw9nx 2mo ago[dead]
- bilsbie 2mo agoI like stop overs but I wish they counted toward flying time.