On Wed, 23 Jan 2008 20:25:26 -0800 (PST), Phil J
wrote in
:

On Jan 23, 9:30*pm, george wrote:

CAT ?


Clear-air turbulence sounds like the most likely explanation, assuming
the computer didn't go berserk.



The official wording of the incident:

http://www.tsb.gc.ca
On January 10, 2008, an Air Canada Airbus A319, registration
C-GBHZ, flight number 190, was enroute to Toronto from Victoria,
when at 0835 mountain standard time, while climbing from FL360 to
FL370, and at about 38 nautical miles south of Penticton, BC,
Canada, the aircraft experienced a sudden upset when it rolled
uncommanded 36 degrees right and then 57 degrees left and pitched
nose-down.


Of course, CAT describes atmospheric turbulence of unknown origins, so
it's rather general.


http://www.faa.gov/airports_airtraff...pubs/PCG/C.HTM
CLEAR AIR TURBULENCE (CAT)- Turbulence encountered in air where no
clouds are present. This term is commonly applied to high-level
turbulence associated with wind shear. CAT is often encountered in
the vicinity of the jet stream.

So where was the jet stream located on January 10, 2008 at 0135Z?

0000Z:

http://virga.sfsu.edu/pub/jetstream/...m_pac_anal.gif

0600 Z:

http://virga.sfsu.edu/pub/jetstream/...m_pac_anal.gif

All:
http://virga.sfsu.edu/pub/jetstream/..._pac/big/0801/

Animation: http://squall.sfsu.edu/scripts/jet_p..._archloop.html



And where is Penticton, BC located?


http://maps.google.com/maps?f=q&hl=e...oc=addr& om=0


It looks like the jet stream was meandering through the area at the
time, and its track shows an anomalous finger jutting to the north.
Given this information, it's hard to rule it out.


Even when contemplating crossing it from different angles it's
difficult to imagine the uncommanded rolls to have been induced by
wing-tip vortices from the wake of a heavy.