Flights grounded in Phoenix

[paiken]

Gonna be a scorcher. Around 40 flights cancelled because of the heat. Forecast for today is 120 F. Seems the CRJ's can't handle the temps...
http://www.bbc.com/news/world-us-can...ource=facebook

[Daveroo]

My local news said tonight that one flight from Phoenix was canceled today.guess its got to be pretty hot for that to happen?..does the heat effect the performance of the engines? or maybe is it soft pavement?..


oops to Sacramento i mean

[johannesl]

The airplanes have only been certified to operate up to 118 degrees, beyond that you become a test pilot with 150+ passengers. No legal department anywhere will allow that.

[PhantomTweak]

And yet, having lived there for nearly 30 years, and hating every second of it, I seem to recall many many 120°+ days. Miserable place. Dessicated, everything the color of sand, dust everywhere, inside or out, hardly anything but small shrubs, and everything there has spikes, spines, poison fangs, or a combination of the above. Plants, animals, insects...
Miserable place.
And people keep moving there, trying to convince themselves that "the desert has a beauty all it's own". No, it doesn't. You want to go for a walk? Better take a couple gallons of water! Watch out for snakes, scorpions, Gila Monsters, solifugids, black-widow spiders...

Anyway, 120° isn't that bad, for the area. I've seen over 110° on Christmas Day. Welcome to Arizona!
Pat☺

[txnetcop]

I used to fly every week sometimes two and three times a week. Phoenix/Scottsdale was one place I always loved to travel to. I remember landing in Phoenix in November and the temp was 105...sheesh! The night sky was so spectacular...
Ted

[Rami]

Good morning,

Not to be simplistic here, but it's also basic aerodynamics. The hotter the air is, the less dense it is. Less dense air = less lift. If there's too little lift, given the weight of the aircraft and the length of the runway to exceed safety limits, it's unsafe or impossible to take off. Also, remember that same principle applies to rate of climb, so if there are obstacles around the airport or other restrictions, that also comes into play.

It is unusual at an airport like Sky Harbor because it's relatively close to sea level, only about 1,100 feet. This is more common on a really hot day in a place like Denver, for example.

In fact, there's an airport here in Massachusetts that's like Hotel California on hot summer days. When the summer days get warm, some planes can't take off again until the air cools in the evening.

https://en.wikipedia.org/wiki/Marlboro_Airport

[johannesl]

The accident in this video was captured by a news crew on a very hot day covering an accident earlier in the day. Notice the plane doesn't leave ground effect, about one wing span.
https://www.youtube.com/watch?v=jjRPY4_XKy0

[Motormouse]

My local news said tonight that one flight from Phoenix was canceled today.guess its got to be pretty hot for that to happen?..does the heat effect the performance of the engines? or maybe is it soft pavement?..


oops to Sacramento i mean

Basically it is because of the air density associated with the air temperature, to add to what Rami said above about aerodynamics and less lift, same applies to the engine. Hotter the air going in, the less efficient the combustion inside engine, and therefore less thrust.

Now, in simple terms, when aeroplanes are test flown for hot (air temp) and high (field elevations) the certified limits in the flight manuals are average temp of the ambient conditions at test time. So if the average was 48c then that is what goes in. The flight manual is master document, limits are limits.


Ttfn

Pete