351–360 of 586 posts
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> Turboprops are jet engines They are certainly turbine engines, but I thought "jet" was reserved for those engines that propel the vehicle solely by their exhaust stream and bypass air. I am willing to be told I'm wrong, though.
Turbofans are by your own definition jet engines. It's just that the bypass air is much larger.
I look forward to watching this one on Mentour Pilot
I look forward to watching this one on Mentour Pilot
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40kg of fuel per minute is a lot but airplanes carry a lot of people. Web searches suggest a 737-800 gets about 0.5mpg at cruise. With 189 passengers in a one-class layout that’s 95mpg per passenger. With 162 in a two-class layout that’s 81mpg per passenger. This is better than a single person in a car but four people in a Prius gets 50mpg * 4 = 200 mpg.
This is what vexes me about the lack of emphasis on highway self-driving. Everyone's obsessed with robo taxis. An overnight trip that's automated could go at 40 mph and get seriously good gas mileage. I mean man with four people would probably get almost 100 miles per gallon. And this would eliminate a lot of short-range flights It should be a lot easier to implement than having to worry about a whole class of proble…
The robo taxi links the last few miles to transit.
I recently travelled from my house in Seattle to my office in SF without ever getting in a car. I walked more in the airport than I did anywhere else.
Home -> Walk 11 min -> Metro Bus -> light rail -> SEA -> SF -> BART -> Walk 2 min to Hotel.
Next time I go down I’m going to take Amtrak. I couldn’t this time because it was full. In 2024 360,000 people rode that route on 730 trips for an average of about 500 people per trip. Looks like Amtrak gets between 0.6 and 2mpg. That’s 300mpg to 1000mpg per person which is better than a Prius’ 200mpg at 40mph.
Seattle to SF is 1019 miles. At 40mph that’s 25 hours, which is an hour slower than the Amtrak schedule.
Waiting on full flight in Europe, good airport, for take off. Pilot says over speaker : " We are delayed becuase FUEL guy got UPSET on tarmac and has QUIT. We know need someone ELSE to fill the plane with FUEL. " Said in a COMPLETELY nonchalant voice.
Immediately I get concerned, try not to think what cause a FUEL TECH to QUIT regarding THIS PLANE and fuel issue. Just close my eyes, relax.
2 minutes later pilot comes on intercom again "For some WEIRD reason, someone wants to get off the plane. Now we have to wait for ground crew to find his suitcasebecause of rules. How annoying.."
Plane waits for an hour on tarmac for BOTH passenger to get off and for FUEL to be finally "resolved".
Arrive eventually at destination.
Most of the trouble would have been avoided if the pilot had not sounded nonchalant about a "NON ISSUE about FUEL that a technician just QUIT OVER". I swear i even rememebr saying the statement with a hint of humour, like what on earth is the problem.
This is a true story, and the fact this incompetence happened to me, well I wouldnt have believed it otherwise.
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Correct, article says they landed with 220kg which is around 6 minutes of average fuel burn over an entire flight - bit less at cruise, a hell of a lot more at takeoff/climb. So I don't think 220kg is enough to do a go-around in a 737 (well, a go-around would've been initiated with a bit more than 220kg in the tank - they burned some taxing to the gate - but you get my point.) I've read around 2,300kg for takeoff and…
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Yeah, when people say "flying has a high carbon footprint", they're not kidding . It's really quite massive. I don't fly any more.
Don't look up the carbon footprint of driving then. That is even higher in comparison to most passenger flights.
As a naive person, I have a simple question - why would they even fly to an airport where there's 100mph winds? Wouldn't ATC know this and tell the flight way in advance to fly to a different destination?
I've been on a couple of flights like that. Once where we did two attempts and landed on the 2nd, the other where we did 3 but the had to divert. Other planes were just managing to land in the winds before and after our attempts.
The other problem is (as I found out on that flight) that mass diversions are not good. The airport I diverted to in the UK had dozens of unexpected arrivals, late at night. There wasn't the ground staff to manage this so it took forever to get people off. It then was too full to accept any more landings, so further flights had to get diverted further and further away.
So, if you did a blanket must divert you'd end up with all the diversion airports full (even to flights that could have landed at their original airport) and a much more dangerous situation as your diversions are now in different countries.
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Naively as an outsider, this situation seems like everything worked as intended? On a nominally 2h45m flight, they spent an extra 2 hours in the air, presumably doing doing fuel intensive altitude changing maneuvers, and were eventually able to land safely with their reserves almost exhausted. I’m a little confused by what there is to investigate at all. How much fuel should they have landed with?
This reminds of discussions following the Fukushima disaster where one commenter claimed that it wasn't a design flaw, because it was an extraordinary circumstance. I found this appalling, because I do not at all think that was the risk profile that was sold to the public; I think people believed that it was supposed to be designed to safely survive 1000-year earthquakes and the tsunamis that they create. Likewise, I…
* they're derived from an estimated probability of the event (independently) happening each year. It doesn't mean that it won't happen for n years. The probability is the same every year.
* the probabilities are estimates, trying to predict extreme outliers. Usually from less than 100s of years of data, using sparse records that may have never recorded a single outlier.
* years = 1/annual_probability ends up giving large time spans for small probabilities. It means that uncertainty between 0.00001% and 0.00002% looks "off by 500 years".
https://practical.engineering/blog/2025/9/16/an-engineers-pe...
That is very exceptional. I've written fuel estimation software for airliners (cargo, fortunately), and the number of rules regarding go-arounds, alternates and holding time resulted in there usually being quite a bit of fuel in the tanks on landing, by design. I've never heard of '6 minutes left' in practice where it wasn't a massive issue and the investigation into how this could have happened will make for interes…
I have known former air traffic controllers that won't fly certain airlines because of a notorious habit some have for queue jumping by claiming they're low on fuel. If they are low on fuel is something else, but in any case when the ATCs have noticed a pattern then something is up. This situation sounds a lot less nefarious, but it does also sound like they should have rerouted earlier.