Computer failure in this case = systems switched off (automatic) as designed. Crew flying manual to keep ahead of the problem. Final result = professional crew handled the situation and landed at the next available airport just in case there were serious injuries. The only big deal is what the press is making of it!!!!!

And of course those injured are now released from hospital as they only had "soft tissue" injuries (bruises). And if they had kept their seat belts on they too would not have suffered any injury. Among those treated were two crew members who did not enjoy the luxury of keeping their seat belts on while providing cabin service.

This below is a better reading than any forum discussion or "news reports"

Extract from the CADORS (Civil Aviation Daily Occurrence Reporting System)

http://www.tc.gc.ca/aviation/applica...ors/splash.htm
-"Enter"
-"National report"
-"Reporting date: 2008/01/10" -->"Search"
-Scroll down to Record #14
(I tried a direct link but it didn't worked)

Latest from CBC is that all injured pax released from hospital. Pax interviews suggest that the aircraft rolled about 60 deg left and then pulled negative g. Possibly there was additional rolling. Duration of event about 15 sec. Very unclear as to whether CAT or electronic problems initiated the event.

I'll be interested in the report.

After an excellent landing you can use the airplane again!

White Knight - you beat me to it.
 

Having grown up in England and spent many years in Calgary, it always amuses me how little knowledge people in Europe have of the sheer size of Canada.

Saying that CAT over Ontario and Quebec affected this flight, is like saying CAT over Beirut affected a London to Paris flight.

For the benefit of the geographically challenged :), I have annotated the turbulence map that GM posted. I see from ehwhatezedoing's post, that the flight was 65nm SW of Cranbrook, just south of the border in Washinton, when the incident occurred. This is just about the beginning of the higher mountains, which extend all the way to the Alberta-BC border, so if it was a CAT event, this is a likely area. This forecast was issued 8 hours after the event, but I couldn't find the previous forecast.

http://i30.photobucket.com/albums/c3...rbulence-1.jpg

Just east of the BC border, the mountains stop abruptly, like this:

http://i30.photobucket.com/albums/c3...cowleycamp.jpg

The Livingstone Range in the picture routinely generates lee waves up to at least 40,000' and you often have wave activity further west, which will be less organized than the front range waves and therefore probably more turbulent.

Note: It is not a coincidence that there are gliders in the picture (Cowley Airport).

The current data (14 hours later) shows strong westerly winds aloft and gusty surface winds from the west at Lethbridge, plus bars of cloud on the satellite images downwind of the Rockies all through Alberta and Montana, all of which point to wave activity. Can anyone find the METARs and Winds Aloft for Lethbridge and Cranbrook for 10 Jan 1200 - 1600Z?

And I've just noticed, what a suitable name for the intersection where the event occurred - ONSET.

On the last long haul flight I took there were frequently at least 9 people queuing for the toilets (not the same toilet, I mean in total). Perhaps manufacturers should consider increasing the number or provide a safe means of queuing? Will be interesting to read the report on who was injured, where etc. I allways fasten belt while seated.

As a frequent flyer and industry insider, i am constantly amazed by the actions of some pax, from the moment the arrive at the terminal its as if the rules apply to every one but themselve's.

If it was not so B***dy dangerous it would be amusing!

Safety brief followed by CC taking to there seats and belting up = pax standing and rummageing in the overhead bin, whilst in selective hearing mode ie only recieving orders from the wife/hubby/partner.

Capt... we will shortly be starting our decent into....... followed by seat belt signs = que for the toilets.

My particular favorite was pax, yes more than one, standing up and retrieving duty free ect whilst still decelerating after touchdown.

The total disregard for there own personell safety yet alone anyone elses beggers belief.
I am not saying that was the case mentioned in this thread, but sometimes you wonder what goes throught the heads when travelling by aircraft.

for this situation , landed at the next available airport just in case there were serious injuries, and the crew did that nice

An autopilot failure which would produce erratic roll as reported by passengers on this flight is extremely unlikely. It is more likely that the autopilot disengaged as a result of extreme attitude changes caused by turbulence. The autopilot on this type of aircraft will automatically disengage when the bank angle exceeds 45 degrees or the pitch attitude exceeds 25 degrees nose up or 13 degrees nose down.

@Eboy:

Great, so those passengers using overhead bins with seatbelt signs on and CAT, what happens when something fall out and injures someone who is actually taking heed of the Captain's recommendations?!

I suggest the term "loosely" fastened was coined by cabin crew when making the initial welcoming PA in order to play down the fact that turbulence can hurt you if you are not properly strapped in. They want to avoid scaring passengers with warnings of the inherent danger of flight. Severe turbulence against a loosely fastened seat belt can damage your internal organs due to the rebound effect not present with a firmly tightened seat belt.

Re "sudden" encounters with turbulence. if it happens in cloud it is sometimes caused by incorrect use of the airborne weather radar. The aircraft flies into the top of a storm cell unseen on radar simply because the crew were paying insufficient attention to the tilt or gain setting on their radar. I have observed crews reading a newspaper on the flight deck while at night in IMC and no one evaluating storm cells in the distance until a huge jolt throws unsuspecting occupants in the cabin off their feet. The captain expressed surprise at the sudden appearance of a storm by saying where did that bastard come from when blind Freddy ccould have seen the tilt control was way to high to pick up nearby storm tops. I always first suspect crew incompetency when someone gets hurt by "unexpected" turbulence.

A3757,

I believe the term they use is "comfortably fastened".:)

That seems like a pretty sensible thing to do. It's not as obstructive as a car seatbelt. Once you have it fastened, you pretty much forget it's there IMO.

RON "Can anyone in this forum suggest what might have caused them to manually land the plane; autopilot failure due to turbulence?"

While this may have been an autopilot failure, it may interest you to know that 9 out ot 10 landings are done manually all the time.

I think it is more like 99 out of 100 landings are flown manually.

check!

Agreed, it was just a figure of speach. Nowadays people seem to think that everything is done on automatics and on automatics only.

For the uninformed:
As far as I know there is no commercial aircraft for which an automatic take off is even possible.

The predicted turbulence for around the time it happened was for moderate turbulence with some severe nearby.

You can see the stored chart at:

http://www.airdisaster.com/forums/sh...3&postcount=12

.

from the http://www.avcanada.caforum....

Hey Guys,

I was on AC 190 yesterday. I just wanted to say that from my point of view the crew did a awesome job. Two of the Three flight attendants were injured and continued to assist the passengers and prepare the cabin for landing. The Pilots kept us informed as to what happened and what we were doing. All I know is that we were in smooth air in cruise when the plane rolled abruptly to the left followed by a roll reversal to the right. There were then about 3 more roll reversal that were getting small in intensity. It seemed to me that after the first roll upset the crew was getting the Plane back under control. The first roll reversal was a very rapid movement. It was nothing that I have ever experienced before. It was a very violent disruption. As you can imagine anything that was not strapped down was airborne. I was lucky that my neither I nor my family was hurt. After the crew had the Plane back under control the Captain
made a PA and said that then had had a computer malfunction and that the problem had been isolated and that they were manually flying the Plane. The rest of the flight was smooth with a nice landing in YYC. I just wanted to say thank you to the crew for getting us on the ground safely.

Sean Atkinson
B757 FO

Reports say that the A-319 arrived in CYYC under "Direct Law".

The Internet give this definition of Direct Law....

DIRECT LAW
Direct law is the lowest level of computer flight control and occurs with certain multiple failures.
Pilot control inputs are transmitted unmodified to the control surfaces, providing a direct relationship between sidestick and control surface.
Control sensitivity depends on airspeed and NO autotrimming is available.
An amber message USE MAN PITCH TRIM appears on the PFD.
If the flight controls degrade to Alternate Law, Direct Law automatically becomes active when the landing gear is extended if no autopilots are engaged. If an autopilot is engaged, the airplane will remain in Alternate Law until the autopilot is disconnected.
There are no protections provided in Direct Law, however overspeed and stall aural warnings are provided.
The PFD airspeed scale remains the same as in Alternate Law.

In my humble opinion...it seems as if there is more information pointing to a massive comuter glitch over any turbulence issue? Why are the other 100's of trans canadian flight not also reporting some degree of turbulence??

Comments??

407 Driver...! I gotta go and peruse an international forum not even including helicopters to find you and your ever welcomed opinions.! Nice "seeing" you again (aka Zazu) . Back on topic though...Good job on the crew regardless of the circumstances. Hope all works out well with the Pax that were injured. Anyone who has done any amount of flying, whether pilot or Pax,will have realized that sometimes your bodily functions do not time properly with the present functions of the machine involved!!! Have patience. Given the present Times I'm sure someone will be found to blame...as always.

Fly safe all
BWB

Could it be that because of the turbulence (let us assume it was turbulence at this point in time) that the aircraft switched from normal law (I guess) to
abnormal law (abnormal alternate law) which more or less means manual flying.

As for the captain announcing to the pax about "computer failure" - is this an easy way of explaing Airbus control logic to pax?

E145 driver moving to A32x...

Hi everyone, my opinion is that a computer failure with this results is highly unlikely but not impossible.

Has anyone consider reading FCOM I 1.27.30 Page 7 ABNORMAL ATTITUDE LAWS?

Not many A32O pilots know in wich configuration they will end up after recovering from this abnormal attitude, this is:

In Pitch: Alternate law without protections with autotrim
In Roll: Ful authority direct law with yaw alternate law

There is no reversion to direct law when the gear is extended



During the abnormal attitude itself the laws are slightly different to the mentioned above.

I am not saying this is what happened but is certainly a scenario not many people are familiar with.

407

thanks for the first meaningful post in a long time on this thread.
while it may be a few days before we know the sequence of events, we now know what is meant by "landing manually"

In our sim training, direct law is initiated and the box is flown that way for awhile...some pilots prefer it to regular ops.


One does wonder if the plane is flying again...or if stress during recovery exceeded any limits?

while I know the A300 is not the A320, I am reminded of an american flight with an upset...pilots didn't advance power on leveloff and stalled.

sweker
and

407 Driver
Encountering severe turbulence on an 319 might cause the autopilot to disengage and the aircraft to revert to the so called 'Abnormal Attitude Law' (this is by design, althought turbulence must be really extreme for this to happen).

The Abnormal Attitude Law is 'direct control' with G-load protection. When control is regained, the aircraft reverts to 'alternate law', i.e.

• Roll is 'direct'
• Yaw is 'alternate'
• Pitch is 'alternate'

and stays in this condition until landing. And as far as I remember, autopilot is n/a, and a manual landing is mandatory when in Alternate Law.

Maybe this was the reason, why the crew was flying manually.
So, if this happenend, than there was no computer failure - the system worked as designed. But let's just wait for the report to be published in a couple of weeks.

Regards,
DBate
P.S. It's been a while since I flew an aircraft from the A320 family, so any current pilot who cares to correct me - go ahead.

eagle21 beat me by a couple of minutes with his post ;)

Hello, this link below gives a few more details. I just placed a section of the article for quick viewing. I like the "This is not CSI" comment

http://www.cbc.ca/canada/story/2008/...t-calgary.html

"This is not CSI," Transportation Safety Board spokesman John Cottreau told the Canadian Press. "It's not just bing, bang, boom. There's an awful lot that goes on.

"We deal in facts. We don't deal in speculation. Sure, we can hypothesize, but those need to be scientifically examined and either proven or discounted."

The board has confirmed what many passengers have already said — that Air Canada Flight 190 not only lost altitude but also pitched violently from right to left before dropping 900 feet.

"The aircraft rolled to the right to about 35 degrees of bank and rolled to the left about 50 degrees of bank and effectively the auto pilot was disconnected," said Nick Stoss of the Transportation Safety Board.

I may be repeating some of the excellent descriptions given by other Airbus pilots but for non-Airbus pilots it may be helpful to have a 'Noddy's guide' to Airbus fly-by-wire control laws. There are 4 recognised states of Airbus flight control capability depending on computer and hydraulic serviceability. They are known as Normal Law, Alternate Law, Direct Law and Mechanical Back-up.

'Normal Law' is the standard flight control mode that pilots see every working day. Most pilots will go their whole professional career and never see any other mode except in the simulator. It requires that most flight control computers are operating normally and all hydraulic systems are functioning correctly. That is the mode for which the Airbus has become famous, whereby such features as limited g-loading, a maximum bank angle of 67° and the inability to stall are provided. Alternate Law is a degraded mode that still provides certain protections but will allow the aircraft to stall and to overbank, for example.

There is a further sub-mode somehwere between Normal Law and Alternate Law known as 'Abnormal Attitude Law' which caters for a scenario where the aircraft is thrown into a flight regime way outside the situations normally catered for in Normal Law. I have no idea if that is what happened in this case, but to give you a feel for what the pilots may have experienced, these are the paramaters that would have to occur for Abnormal Attitude Law to be invoked:

Pitch attitude > 50° nose up or 30° nose down
Bank angle > 125°
Angle of attack > 30° or < - 10° (- 15° for A319 and A321)
Speed > 440 knots or < 60 knots
Mach > 0.91 or < 0.1

The system applies an abnormal-attitude law in pitch and roll if the aircraft exceeds any of these limits in flight. The law in pitch is the alternate law with no protection except load-factor protection and without auto trim. In roll it is a full-authority direct law with a yaw mechanical.When the aircraft has recovered from its abnormal attitude, the flight control laws in effect are :

in pitch : alternate law without protection with autotrim.
in roll : full authority direct law with yaw alternate law.
There is no reversion to direct law when the pilot extends the landing gear.

I hope that may be helpful to non-Airbus pilots, but in no way suggests that is what occured in this case. It nonetheless gives you a feel for the severity of the situation required to enter this scenario.

@ India Four Two

METAR for Lethbridge:

http://english.wunderground.com/hist...tename=Alberta

METAR for Cranbrook:

http://english.wunderground.com/hist...q_statename=NA

Unfortunately no winds aloft history found.

Regards

Please do not jump up and shout at me. I AM NOT SAYING THIS COULD HAVE HAPPENED IN THIS CASE.

When my company first got their A320's we had similar incident. The cause was put down to the F/O sitting cross legged and his Knee pressing on to the side stick. If I remember correctly they thought either the pressure gradually increased untill the autopilot let go or that he moved and knocked the side stick hard over. Neither pilot could remember this happening but the FDR showed the side stick movement.
Again if I remember rightly the a/c went 60 deg one way then 60 the other as the other pilot grabbed his side stick to correct. Then a bit of dual stick input (it sums the inputs) untill things settled down. Luckily no one was hurt.

Anyway as a matter of interest. & be careful crossing your legs, especially with one ankle on the oposite knee in an Airbus. :eek:

Lufthansa requires passengers to wear seatbelts AT ALL TIMES when they're seated.

Cockpit also notifies SLF of any KNOWN expected turbulence, but it certainly makes sense to me.

Is there any reason NOT to comply with Jimmy Saville's "Clunk Click Every Trip" exhortation?

Many other airlines encourage this too.

However, the emphasis is "when seated". Not everyone might be seated at a given moment for a variety of valid reasons. This may have been the case here. We don't know, we weren't there.

I keep my seat belt fasten at all times when seated. I often reflect how that's not going to save me if we happen to hit unexpected turbulence as I make my way to the lavatory. Sod's Law!

I flew from ORD to CVG with AA and on approach not once were we told to 'belt up'

on the seat back in front of you on every US airliner is a small sign indicating that whenever you are seated you should fasten your seat belt.

One possible scenario could be the malfunction of both ELAC ( elevators an ailerons computer). In that case, the ailerons are lost and the autopilots as well.

what would happen if "someone" switched the elacs off then on in flight???????????????

To my knowledge, it is recommended not to reset the ELAC in flight if a not commanded roll action occurs during the flight.

Been a while since I flew any "bus", but isn't pitch alternate and roll direct the same regime as is blended in when the aircraft enters "FLARE" mode? In this regime, it's pretty much just a regular, old-fashioned airplane.

I remember one morning climbing out of YYZ over west Pennsylvania out of 380 on the way to 390 in an A330...literally smooth as glass from surface to about 383...not a cloud in the sky...and then all $%^& broke loose. CAT was so severe that we couldn't even read the FCU/Instruments. A/P kicked off and A/T was disengaged in record speed with consensus rapidly achieved that a rather more expeditious return than normal to 350 would be a sound course of action.

Moral of the story: keep your seatbelts fastened! :bored:

When there is confusion...
 

From Norman Stanley Fletcher and some others :
..."to give you a feel for what the pilots may have experienced, these are the paramaters that would have to occur for Abnormal Attitude Law to be invoked:

Pitch attitude > 50° nose up or 30° nose down
Bank angle > 125°
Angle of attack > 30° or < - 10° (- 15° for A319 and A321)
Speed > 440 knots or < 60 knots
Mach > 0.91 or < 0.1..."
All the above is correct as are all the posts dealing with flight control reversions.
They, IMHO, are hardly applicable in this case as :

• They were on autopilot
• A passenger was quoted as reporting that the captain came on the PA and said that " the A/P had been knocked-out and they were flying manually".
• This points to an A/P disconnect.
  The conditions are a lot smaller than those for a reversion :
  -High speed protection is active (Vmo bust)
  -Alpha protection is active (AoA greater than Alpha prot +1° )
  -Pitch attitude over 25° nose up or 13° nose down
  -Bank angle in excess of 45°

As everybody was talking about 50 to 60° bank angles and some porpoising, one at least of these reported values could have triggered an A/P disengagement.
Please note that in this case, they could have re-connected the A/P when calm conditions were resumed. The reason why they - apparently - did not could be explained by caution and - maybe - confusion as to the causes of the upset.

it seems that the crew changed altitudes looking for smoother air prior to the "upset". if that is the case, why was anyone standing? including the fa's? I would have told the fa's to delay service if turbulence was possible.

and if the crew did look for smoother air, it should have been obvious that this was a turbulence induced event. now, has the plane been put back into service or was it overstressed?

Latest news from CBC french network is the upset would be caused by a close encounter with waqke turbulence from an american stealth aircraft.....?????:rolleyes: :rolleyes:

Here is the Anglo version:
http://www.cbc.ca/canada/calgary/sto...ght-cause.html

An Air Canada Airbus on its way from Victoria to Toronto dropped suddenly in midair likely because of the wake from a passing plane, according to a Calgary newspaper report.

The Calgary Sun quotes Real Levasseur, the chief investigator of the Transportation Safety Board, as saying there was a "high probability that an external force may have caused the incident."

Flight AC190 was diverted to Calgary on its way from Victoria to Toronto.
(CBC) The Airbus A319 had been flying for about 30 minutes on Jan. 10 when it suddenly rolled and dropped about 300 metres. Passengers said the pilots reported a computer failure onboard at the time.

Flight AC190 was diverted to Calgary, where 10 passengers and crew members were taken to hospital with mainly soft-tissue injuries. All were discharged several hours later.

The aircraft's roll of 46 degrees was described by an Air Canada pilot as an unusual occurrence. "The pitch caused by a regular turn generally ranges around 30 degrees," Serge Beaulieu, spokesman for the Air Canada Pilots Association, told the Sun. He also confirmed wake turbulence was a possible cause.

The incident happened at the edge of U.S. airspace near the B.C. Kootenay Mountains. The TSB has asked its U.S. counterpart to provide navigational recordings from the area.

Levasseur refused to speculate on the mystery aircraft, or to discuss the possibility it could have been a B-2 stealth bomber, according to the Sun report.

U.S. Air Force officials told the newspaper Tuesday that stealth bombers always leave a radar signature when they are not flying over a war zone.

This reminds me of a story a from friend of mine who was AC cabin crew. Disclaimer: (1) I am SLF; and (2) She told me this over 10 years ago, so I don't remember all the details.

She was flying out of Vancouver on a B767 and was in the cockpit when the two pilots suddenly looked concerned. Turns out, a US stealth jet was flying below them. I know she told me how many feet separated them, but I can't remember now. However, it was close enough that the two pilots were not impressed.

slinks back to steerage

Second jet may have caused plane plunge???
 

http://www.canada.com/victoriatimesc...111f0a&k=38168

Just posting the story...