What, Exactly, is Turbulence?
May 17, 2005 | 4:13 pm
#1
Original Poster
Join Date: Jun 2004
Location: STL
Programs: WN, DL, AA; Hyatt or Wyndham
Posts: 1,105
What, Exactly, is Turbulence?
With the Midwest and Southwest incidents in the news recently, it got me to thinking I really don't understand the science of turbulence.
So when you're bopping along at 35,000 feet, and you suddenly drop, oh, 3000 feet, is that caused by the upper-level equivalent of a wind shear -- essentially, a downdraft of air that pushes the plane down at a greater force than the engines are propelling it forward?
Similarly, a sudden rise -- is that caused by a powerful updraft of air?
Or, am I completely missing it and some other force is at play?
So when you're bopping along at 35,000 feet, and you suddenly drop, oh, 3000 feet, is that caused by the upper-level equivalent of a wind shear -- essentially, a downdraft of air that pushes the plane down at a greater force than the engines are propelling it forward?
Similarly, a sudden rise -- is that caused by a powerful updraft of air?
Or, am I completely missing it and some other force is at play?
May 17, 2005 | 6:18 pm
#3
Join Date: May 2003
Location: GEG
Programs: Motel 6 Club Avoir Le Cafard
Posts: 5,027
Originally Posted by Delta Hog
With the Midwest and Southwest incidents in the news recently, it got me to thinking I really don't understand the science of turbulence.
So when you're bopping along at 35,000 feet, and you suddenly drop, oh, 3000 feet, is that caused by the upper-level equivalent of a wind shear -- essentially, a downdraft of air that pushes the plane down at a greater force than the engines are propelling it forward?
Similarly, a sudden rise -- is that caused by a powerful updraft of air?
Or, am I completely missing it and some other force is at play?
So when you're bopping along at 35,000 feet, and you suddenly drop, oh, 3000 feet, is that caused by the upper-level equivalent of a wind shear -- essentially, a downdraft of air that pushes the plane down at a greater force than the engines are propelling it forward?
Similarly, a sudden rise -- is that caused by a powerful updraft of air?
Or, am I completely missing it and some other force is at play?
May 17, 2005 | 7:08 pm
#4
Join Date: Apr 2005
Location: PHX
Posts: 3,794
Up and downdrafts are a factor, and head and tailwinds (affecting airspeed) are too. The wings produce lift based on the speed of the air passing over them. If you fly through a rotating column of air, you'll get abrupt changes in lift, causing the aircraft to rise or fall.
May 18, 2005 | 7:35 am
#5
Original Poster
Join Date: Jun 2004
Location: STL
Programs: WN, DL, AA; Hyatt or Wyndham
Posts: 1,105
Originally Posted by gt_croz
Not to ignore your questions (I don't know the answer) but what incidents do you speak of?
http://www.flyertalk.com/forum/showthread.php?t=433460
http://www.flyertalk.com/forum/showthread.php?t=432757
May 18, 2005 | 9:43 am
#6
Join Date: Sep 2004
Location: (not Montana. Nor is my name really Helena, nor am I female)
Programs: Delta, USAirways, Starwood, Priority Club, Marriott, Amex
Posts: 2,557
Originally Posted by mbstone
Air routes are just like other roads. In some localities they are poorly paved.
May 18, 2005 | 8:21 pm
#7
Join Date: Dec 2004
Location: Naples Island, CA
Programs: 1K
Posts: 108
The overwhelming majority of the time, potential turbulence is easy to forecast and visualize on a flight route (cumulous clouds for example). Clear air turbulence is the kicker, as it rears its ugly head with no visual indicators. Check this site out for some educational reading :
http://www.casa.gov.au/airsafe/trip/turbulen.htm
The best people to talk with about air movement, turbulence, clouds and thermals are guys and gals who fly without engines - like sailplane, hangglider and paraglider pilots. They use air currents and thermals to get from place to place, and in some cases turbulence is something they seek as it indicates rising air. Of course, they also have a saying that goes something like " If you could see what the air was doing around you, you'd never fly in it!"
http://www.casa.gov.au/airsafe/trip/turbulen.htm
The best people to talk with about air movement, turbulence, clouds and thermals are guys and gals who fly without engines - like sailplane, hangglider and paraglider pilots. They use air currents and thermals to get from place to place, and in some cases turbulence is something they seek as it indicates rising air. Of course, they also have a saying that goes something like " If you could see what the air was doing around you, you'd never fly in it!"
May 18, 2005 | 9:44 pm
#9
FlyerTalk Evangelist
Join Date: May 2001
Location: LAX; AA EXP, MM; HH Gold
Posts: 31,789
Originally Posted by flymrpuffy
Of course, they also have a saying that goes something like " If you could see what the air was doing around you, you'd never fly in it!"
May 20, 2005 | 11:34 am
#10
Join Date: Feb 2002
Location: BNA
Programs: HH Silver. (Former UA PP, DL PM, PC Plat)
Posts: 9,554
Originally Posted by Delta Hog
So when you're bopping along at 35,000 feet, and you suddenly drop, oh, 3000 feet
Turbulance is caused by flying through parcels of air which are moving in different directors or at different speeds.