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It's Too Hot For Some Planes To Fly In Phoenix (npr.org)
In Phoenix on Tuesday, temperatures were forecast to climb as high as 120 degrees Fahrenheit, causing more than 40 American Eagle regional flights out of Phoenix's international airport to be canceled. NPR reports: American Airlines said in a statement that the Bombardier CRJ aircraft used on some shorter routes have a maximum operating temperature of 118 degrees. For bigger jets, the threshold is higher. The carrier says that, for example, Airbus aircraft have a maximum operating temperature of 127 degrees and that for Boeing, it is 126 degrees. As USA Today reports: "Extreme heat affects a plane's ability to take off. Hot air is less dense than cold air, and the hotter the temperature, the more speed a plane needs to lift off. A runway might not be long enough to allow a plane to achieve the necessary extra speed." Bianca Hernandez, a meteorologist with the National Oceanic and Atmospheric Administration, tells NPR that Phoenix is seeing an unusually strong high-pressure system, which is causing the soaring temperatures.
This is one effect of global warming no one foresaw.
Uh, it's actually a pretty well-known issue. Lots of flights in the Middle East tend to be scheduled at night or in cooler parts of the day to avoid such problems. Larger planes with more powerful engines can often cope with higher temperatures, but it's a problem for less powerful planes that can't accelerate enough to get off the ground with a short runway.
It's a known issue. But so far not a common-enough one to extend runways or do expensive plane redesigns.
https://en.wikipedia.org/wiki/...
Nothing new or myterious. High altitude airports (i.e. Denver) struggle with it all the time. Helicopters, in particular, have to pay close attention to DAlt. A friend told me an entertaining story of spending a week trying to get a chopper to take off from a plateau in Nairobi... combination of a weird pressure change and a heat wave.
Log in or piss off.
And this is why we need better passenger rail,
Yeah. Good luck with that in the heat.
Have gnu, will travel.
I have a few guesses as to why they don't have this problem in Denver but they do in Phoenix. One you point out is that Denver likely has longer runways. Why not extend the runways in Phoenix then? Likely because this happens so infrequently that they did not want to go through the expense of extending the runway. I got to talking to an engineer that works on airports. As I recall the runways are dug something like 30 feet into the dirt and filled with concrete. That's a lot of concrete to make up for a few hours of inconvenience every few years. This is not your typical concrete and the surface is engineered for keeping traction in all kinds of weather. Every extra foot of that runway must be very expensive.
Another possibility is that airports in Phoenix are older and with improvements in optimizing airframes over the years for some norm the margins got slimmer. This means that over time the airplanes needed longer runways but the airport couldn't extend the runway even if they wanted to. Old airports tend to have the city build up around it and pen it in from expanding.
It could also be that nothing changed physically but the rules under which they operate did. It could be that somewhere in the world an airplane didn't quite make it off the runway in the heat so the FAA decided that the rules on the safety margins had to be changed. It's quite possible every aircraft that wanted to take off could do so, and in the recent past the FAA would have allowed it. But because of a desire to maintain an abundance of caution the FAA grounded those flights.
I recall someone pointing out that we have not seen a commercial jet crash that resulted in fatalities since 2001. We've seen big planes crash since then but no deaths. We've seen people die in plane crashes but not on a major airline on a regularly scheduled flight. I think the FAA would like to keep it that way as long as possible.
I am armed because I am free. I am free because I am armed.
One admittedly minor advantage of Celsius is that most of the temperatures humans are interested in only need two digits. So your air-con can save on an extra 7-segment LED module, or you can have 3 and go to 0.1C precision which is over 5x better than a 3 digit Fahrenheit scale.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
The Urban Heat Island effect is most of that - up until 1965, Phoenix was a minor city, and didn't get much past 100,000 until 1950 or so.
Adding people and buildings makes areas a LOT hotter.