-40 C

[jagabom 21]

Well it was -40C at CYWG today. Winnipeg, Manitoba, CANADA.That is the same temp as F. A jet flew over today going north west to somewhere in ASIA. At that temp, the plane sounds like it is landing here. There is no sound so unique as the sound of a jet flying over in -40 temp. For those of you in the south, there is nothing to compare it to.JimCYWG

[Guest christianholmes]

Wow- I have never, ever been in air that cold.Is that on the ground? If so, at altitude that would be -164C. That can't be right?

[Guest Rockcliffe]

>Well it was -40C at CYWG today. Winnipeg, Manitoba, CANADA.>That is the same temp as F. A jet flew over today going north>west to somewhere in ASIA. At that temp, the plane sounds>like it is landing here. There is no sound so unique as the>sound of a jet flying over in -40 temp. For those of you in>the south, there is nothing to compare it to.>Jim>CYWGFunny you mention that. I took my daughter to school yesterday when it was balmy (by 'Peg standards) -29C and a 737 out of Ottawa passed overhead at a couple of thousand feet. I just about ducked it was so loud.BlairCYOW

[KevinAu 441]

>Wow- I have never, ever been in air that cold.>>>Is that on the ground? If so, at altitude that would be>-164C. That can't be right?>>No, it doesn't work that way because of the nature of the atmosphere layers. It will be colder than standard up there, but it is not so linear that you are going to get something outrageously low like that. The lowest you would probably see at the airliner cruising altitudes would be in the -60C'ish range. The stratosphere, which begins at about -54C prevents temperatures getting much lower than that. In fact, it stabilizes there and then even gets warmer as you go higher until you reach the mesosphere. The actual effect of such cold weather is that the atmosphere itself shrinks and the top of the Earth's atomosphere will be closer to the surface.

[Mace 1,927]

Help a southern boy out. Why is a jet so loud in cold weather?Does sound travel farther in cold air? One thing I have noticed--when it is cold here, or there is some snow around, every sound seems magnified...but I always thought that was because it was so still.RhettAMD 3700+ (@2310 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2 GB Corsair XMS 2.5-3-3-8 (1T), WD 250 gig 7200 rpm SATA2, CoolerMaster Praetorian case

[Guest HaroldP]

Rhett,I am no expert by ANY stretch of ANY imagination but I wonder if it may be due to less moisture in the air to absorb/deflect sound?I may not understand the theory but have lots of experience. I have an uncle that used to live along an approach but still 15-20 miles out. When the 747's go over, I too want to duck.Harold

[Guest christianholmes]

>>Wow- I have never, ever been in air that cold.>>>>>>Is that on the ground? If so, at altitude that would be>>-164C. That can't be right?>>>>>>No, it doesn't work that way because of the nature of the>atmosphere layers. It will be colder than standard up there,>but it is not so linear that you are going to get something>outrageously low like that. The lowest you would probably see>at the airliner cruising altitudes would be in the -60C'ish>range. The stratosphere, which begins at about -54C prevents>temperatures getting much lower than that. In fact, it>stabilizes there and then even gets warmer as you go higher>until you reach the mesosphere. The actual effect of such>cold weather is that the atmosphere itself shrinks and the top>of the Earth's atomosphere will be closer to the surface.Thanks for clearing that up. The Jepp PPL books don't really go that into it :) I'm not sure there are many metals (if any) that would not break at that temperature!It's actually comforting to know that the airframes hold up in that temperature- I get a little squirrely flying in 20 degree weather here in the Warrior. I'm always afraid I'm going to do a steep turn and have the wings shear off :)

[MarkW 1,493]

They don't call it Winterpeg for nothing!!!!Mark.

[Geofa 108]

I did my night commercial xcountry at 15 below zero on the ground level.I never worried about the wings coming off-but I did worry about if the engine quite and we had an off airport landing.From being in the Civil Air Patrol-you might be spending 12-18 hours in those conditions before being rescued even if on an ifr plan!Always dress for the worst!http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg