Jan 27, 2008

A319 upset - the investigation continues...

Another possible explanation focuses on wake turbulence as the cause of Air Canada 190's upset earlier in the month, according to this article and reported here:

To help you visualilze wing tip vortices and wake turbulence I found these videos on Youtube:

Early research - note how long vortices persist...

Altitude research - note the sudden rolling movement induced on the B737

The size of the vortices increases with the size of the airplane. So it is routine for smaller aircraft to be spaced further behind larger aircraft. If a B-747 was flying ahead and above Air Canada 190 on this route, there is certainly a possibility that the vortices may have been the cause. Unhappily in most weather conditions, there is no way for pilots to see these air currents, nor do we have any instruments to detect them.

Here's a link to more information on vortices at Wikipedia:

2 comments:

MathFox said...

I should pick up those dusty fluid mechanics tomes from the bookshelf and take a look at some alternative formulations of the Navier-Stokes equation. At a first glance it looks like it's possible to get a good first-order approximation of how the pair of wing tip vortices decays over time.

However there is one twist, the stability of the air influences the decay of the vortices: if the air mass is stable (a small pocket of air feels comfortable at its current altitude) it will help damping a vortex. However if the air mass is unstable, the air particles will like to go up and down with the vortex and amplify it.

On a different, but related topic: could planes act as "flying weather stations" and (automatically) send information like air pressure, temperature (and wind) to a ground station? It may help both weather prediction and study of clear air turbulence.

Aluwings said...

Development of wake turbulence detection systems is ongoing but frustratingly slow.

One article on acoustic detection

Another project to develop onboard detection.

As for the concept of flying weather stations, this is certainly possible and I've wondered for years why the airlines aren't actively promoting this idea as a means of improving forecasting accuracy. Perhaps this data would even be an attractive commercial product to be sold to weather agencies and research projects?