231–240 of 251 posts
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My understanding is that pilots frequently fly parts of the cruise so that they have adequate "stick time" to stay fresh and familiar with the machine.
Probably not the actual cruise (30k+ feet at M0.7+), but definitely some of the nicer approaches and departures. Hand flying an airliner in cruise within the tiny strip of air it’s allowed to fly in (google Reduced vertical separation minima) is no fun.
Earlier quoted context omitted.
My understanding is that pilots frequently fly parts of the cruise so that they have adequate "stick time" to stay fresh and familiar with the machine.
Probably not the actual cruise (30k+ feet at M0.7+), but definitely some of the nicer approaches and departures. Hand flying an airliner in cruise within the tiny strip of air it’s allowed to fly in (google Reduced vertical separation minima) is no fun.
Earlier quoted context omitted.
Probably not the actual cruise (30k+ feet at M0.7+), but definitely some of the nicer approaches and departures. Hand flying an airliner in cruise within the tiny strip of air it’s allowed to fly in (google Reduced vertical separation minima) is no fun.
Pilots are still doing a job, and sometimes that job involves keeping their skills fresh and honed, or working around a partially non-functional or degraded autopilot. Sometimes it's even a matter of personal preference, with some pilots preferring more hands on time than others.
There are parts of the flight where hand flying is allowed, but those are the parts closer to the ground (or on very short hops where the cruise altitude is significantly lower than usual).
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Yup. I'm in Sydney and it's one of the most disappointing things about Australians. The inability or unwillingness to understand things like this.
What is there to understand? Person A does not like Australia, and leave. Good for him/her and good for Australia. If you don't like , you don't like.
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Oh, I thought it was just me! All the Airbus planes have horrible autopilots that gradually rise and fall, in a barely noticeable way. I found myself feeling irritated and wished the source code was opensource so I could have a look at it.
Are you telling us this as a pilot or a coder? Calling it's autopilot is horrible is a lot of stretch.
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Sure. But the conversation here is about biofuel. Leet's say I want to fly to London because I'm sick of the gorgeous weather in California. In order for aviation to exist, we need energy storage substantially denser than what batteries can currently provide. Our options are A) Biofuel, which captured CO2 in its development, or B) Fossil Fuels, which did not. A) is objectively the superior option, because buying said…
Burning a log you just cut is no different from burning a log you dug up. You've accomplished nothing whatsoever in reducing CO2 emissions.
Maybe this will help you think about it:
If I drove over to the supermarket and back, and then planted a tree that would sequester an equal amount of carbon to the amount I released driving to the supermarket, would you agree that I am offsetting/reducing my emissions?
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It’s not just about hubs but about frequency as well. If given the choice flyers often prefer the airline flying 3 or 4 737s at varying times of day over the one big airplane.
which flyers ? I'm not sure they spread evenly tourists all want the earliest and last flights to arrive early and leave late, and not waste a day of vacation ppl who go on a weekend want the last trip on sunday that arrives not so late so that they can sleep, or the earliest trip on monday And when you're going on a journey in the middle of the day, you're sometimes feeling alone in there. Beyond offering more trips…
A young single person, is different from a family with kids, which is different from a group of young people on a party trip. A young single person can often have a bag ready and depart directly from work; a family with kids may want to depart in the morning to be there super early; a group of young people hungover from last night's bender may want an afternoon flight.
Not to mention, often you are picking between an optimal departure time and an optimal arrival time. For instance, I know people who love redeye flights to fly across the continental US, but I hate them because they mess up my sleep.
The A380 is essentially a really big bet on a one-size-fits-all plane, for travel segments that rarely are.
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None of the engine manufacturers are interested. That's what killed the A380--Rolls Royce pulled out of a re-engine deal that would've brought A380 engines into the 21st century. "Green" concept showcases notwithstanding, all the engine manufactures seem to have decided to cut back on investment and coast for awhile. Something will need to change to spur competition in the engine space, and then we might see hungrier…
The latest and greatest engines are not that far from the theoretical thermodynamic efficiency limit. So future designs are running into the hard part of the asymptote. I doubt airlines are actually interested in committing tens of billions of capital, today, to get a dozen % improvement in fuel efficiency a decade from now. And why would a private investor take such a huge risk without guarantees of making it back s…
No. Even if an engine got to the Carnot efficiency, you can still improve it. Massively. You can push a certain quantity of air with a velocity v or 4 times that quantity with half the velocity. The second option produces twice the thrust, for the same fuel consumption. That's the reason engines are getting larger and larger, and going for higher and higher bypass ratios.
Separately, the maximum theoretical (Carnot) efficiency depends on how hot the engine runs. GE has introduced turbines made of silicon carbide, which can withstand absurdly high temperatures. Silicon carbide melts at more than 2800 Celsius, but they don't push it to such limits. But they push it to more than 1300 Celsius [1]. Military jet engines run much hotter though. Exact numbers are classified, but according to [2] the temperature inside F35's engine might reach 2000 Celsius (the actual number is obviously classified). Of course, military jet engines are many times more expensive than civilian ones, with higher maintenance costs, and lifespan about 2 orders of magnitude shorter.
Still the fact that they can run this hot means improvements for the civilian jet engines are possible. And they will happen.
[1] https://www.ornl.gov/news/ceramic-matrix-composites-take-fli... [2] https://www.researchgate.net/publication/285727346_Fahrenhei...
Having escaped Australia during the middle of the pandemic, I'd like to correct this article: Australia's only long-haul carrier during the pandemic was United. Thanks United for getting me out of Australia!
Qantas basically ceased all international operations except when underwritten by the government.