Citizen Bytes

yer not cheering me up.

Wow, here come the experts. If there's one thing that irritates professional aviators, it's this speculation based on the thinnest possible amount of information every time an aircraft crashes. How about we let the investigators do some analysis and then tell us what happened in the cold light of day? Other than making you feel good as some clueless journalist defers to your expertise, what exactly has this done to help anybody come to grips with this tragedy? My take: let's all sit back, grow some patience, and let the facts do the talking.

As someone who is anxious about flying anyway, this article has pushed me over the edge. Thanks! Perhaps some perspective might be in order, like how often planes are 'torn apart' by invisible forces greater than several Hiroshima-type bombs which pilots have no way of discerning or avoiding in mid-flight???!!!! I sure hope you're never my pilot. I can just imagine your pre-flight announcement: "Good morning travelers. According to Wikipedia..."

I'm an aerospace/electrical engineer with about 20 years of flight operations experience. CAT could certainly have been responsible, and CAT is often found around severe storms.

What troubles me is the report of a number (12?) failure messages sent from the aircraft just prior to the suspected impact, relating to a number of electrical system failures.

The CEO of Air France characterised these failures as a "totally unprecedented situation in the plane". That type of language makes me suspect a novel system-wide electrical failure may have occured. Unprecedented leads me to think that may equal 'beyond design considerations'. Time will tell.

The A330 is a digital fly-by-wire (FBW) aircraft, which means there is no direct mechanical connection between the side-stick controller and the flight controls. There are numberous degraded modes of operation in the flight controls, but the possibility of a system-wide failure does exist (even if highly improbable).

There has been some experience with significant FBW failures in both the military and civil sectors.

I'm also trying not to remember some of the past software/operator integration issues experienced by Airbus airframes. Highly complex software-based systems can at times have undetected failure modes.

Further to the comment above from the pilot, I experienced clear air turbulence a couple of years ago while aboard an Airbus A320 above the prairies. Based on that experience I have to think turbulence is a possible scenario in the Air France flight.

On a clear, smooth, sunny day the plane suddenly went on its side then at a steep nose down angle. The engine noise was deafening and a flight attendant seemed to float.

The plane seemed to fight it for a minute or so as the nose went up and down and over again on our side a couple of times. I noticed the ground coming up. The extreme flexing motion of the wings was quite something to see.

Then it was over as suddenly as it started. After a couple of minutes the pilot came on, his voice shaky, and said he was not sure what happened but thought we had possibly gone through a shifting jetstream a.k.a. clear air turbulence.

Nobody was hurt, I believe this was because air passengers have become accustomed to keeping their seat belts engaged.

As I went to the rear galley to order my first ever double Scotch on an aircraft, I ran into the pale, formerly floating, flight attendant who informed me that he was on his first working flight.

Your comments are valid, not that anyone wishes to take away from the thoughts for the passengers and crew of flt 447.

I personaly ensure I wear my seat belt at all time's during a flight as I've seen cabin crew hit the ceiling in serious downdrafts on north atlantic flights.

I thought the new aircrafts are equipped with advanced communication system, such as online GPS, which reports their position and speed to other airline continuously. Why they are not equipped with something like this?

Wow, interesting explanation given other reliable sources have indicated severe CB's (Thunderstorms) were present in the convergence zone along the equator.

I think I like the "other" experts explanations better as its now hurricane season and they do develop in the area in question before moving west towardt the Caribbean.

In fact, if you check out the satellite photos available on Environment Canada's site you'll notice the convective activity in that area.

I'd look at the existing weather data during the tragic event before jumping to any conclusions (i.e. CAT).

Maybe ocean liners will make a comeback... I would love to sail across the Atlantic - never mind the time it would take. As long as there are no hurricanes!

Are there not any common indicators of turbulence in the air? Can a pilot not have permission to turn away or even back when encountering an unstable air mass? At what point does a pilot concur that it's okay to take a loss at the pumps and fly away from something like this and refuel at an International airport in Africa before continuing on? Why would ATC allow this flightpath to proceed through a storm such as that?

The reason I ask is because I think that by now there would be some sort of electronic monitoring device such as a temperature sensing RADAR or combination of that with something to do with a forward looking water vapour sensor that would indicate and predict air flow patterns in the path of a multi million dollar airliner. There are too many predicable elements here not to have seen it coming I think.

I am not an aviation expert and only an amateur pilot. I however feel a strong intuitive reluctance to allowing flight safety of large passenger aircraft to rest on fly by wire control systems like the airbus has, no matter how many redundancies there are in the back up systems.

That reluctance only amps up when there is also a complete or nearly complete reliance on electronic primary flight instruments. The airbus aircraft I think rely almost exclusively on both. They say there is some manual control of control surfaces through rudder trim and elevator trim and engine thrust.

OK maybe on a cavu (clear) day and no serious turbulence. Visualise them moving into severe turbulence with multiple thunder cell activity at night at cruising altitude then having a catastrophic electrical failure resulting in loss of basic flight controls and perhaps simultaneous loss of electronic instruments, possibly already in cloud so therefore relying on instruments to control the aircraft. With no horizon visible by which to maintain attitude control.

Trying to maintain control with the trim and engines in turbulence under those conditions would likely be impossible. I don't think anybody could do that. There could be a loss of control and eventually extreme aircraft attitudes possibly causing structural failure and/or impact with the ocean in the end. Given the known reports of electical failures and depressurization and also known thunder cell activity and reported severe turbulence at night it would seem to be a real possibility in this situation.

I think they should require all commercial passenger aircraft to have a manual flight control backup system augmented by a complete set of mechanical, barometric, magnetic, and air pressure operated instruments as back up to the electronics. Then those extremely competent and highly trained professional pilots would have something to work with even in the worst case scenarios of complete power failures. I think it is an inherent weakness in design and construction. Not safe enough for this purpose, military fighters maybe but those guys can eject if necesasary.

Condolences to the families of all those lost may they find peace.

In other words, travelling close to the edge of space in a fragile pressure vessel glued together out of advanced composite materials at hundreds of kilometers per hour with a computer, electrical system, and hydraulic system separating the pilot's hands from the control surfaces IS NOT WITHOUT RISK.

Surprised?

Our technology is amazing, but it's fallible. It's amazing that air travel is as safe as it is, considering the power of the planet and the size of humanity's ego.

I believe the cause was a electrical problem which caused the rudders to become un-operational. Which caused the plane to plummet possibly circling a couple times, depending on which rudders ceased to operate.

My heart goes out to all the Families of the Victims, may you find peace knowing where they are..in your heart.

thank you, and take care

I had a rough ride March 25/26 this year enroute from Sydney to Los Angeles. Not CAT but it was difficult to keep the food on the food tray. Two bouts of 10 minutes each - worst I have ever experienced in 25 years of flying. Of course we were only at 30,000 feet???? which I thought might have been the reason for the rough ride. Nearer to LA we climbed to 39,000 feet and it was totally calm.

CAT will probably be ruled fairly quickly or dismissed all together. Severe thunderstorms with tops estimated at 51000 ft are known to have turbulence and differs from CAT. CAT is when two different airmasses meet or there is lift caused by a mountain range.

The Air France airplane was operating inside the Inter Tropical Convergence Zone. Reports and satellite indications lead one to believe that the airplane may have traversed inside a cell which is a more likely scenario. Once inside the thunderstorm cell the jet probably surcummed to any one of the phenomenon that can occur like: Lightening, hail, severe rain, snow or ice, up and down drafts, windshear, or severe turbulence (not CAT).

It is incredibly difficult to navigate around a severe line of thunderstorms because although weather radar might show what is immediately in front of you. The radar signal weakens when presented with severe moisture from one thunderstorm and there maybe a thunderstorm behind it that is even worst which isn't displayed to the pilots radar screen. In other words you may see one cell and completely be oblivious to a potentially more dangerous cell behind it.

It is much too early to speculate what caused the demise of this plane but if there was an electrical failure on board in those conditions you can be sure that the plane was in trouble. No pilot can safely navigate an airplane long in the dark and in or near a line of severe thunderstorms.

CAT will probably be ruled out because ultimately there was no clear air to have CAT. The airspace was contaminated with thunderstorms. Severe turbulence might have been a factor but investigators are going to want to know what caused the electrical failure. That won't be CAT.

Wikipedia should not be quoted by "experts".

As a commerical pilot as well with thousands of hours as well... I would not have to "quote" wikipidia on information I already SHOULD know. As others have said, we can't even begin to speculate what happened. We need to stay calm and wait for the cockpit voice recoreder and digital flight data recorder.

Bunbury - to hopefully set your mind at ease, at least somewhat, in the cockpit there is a weather radar display that shows the pilots areas of precipitation such as rain (intense) and hail that are associated with thunderstorms. The radar 'beam' bounces off the droplets and hail inside thunderstorm clouds and returns to the radar dish in the nose of the aircraft. The most intense precipitation regions appear in red (danger!). Clear Air Turbulence or CAT, however, cannot be detected by aircraft weather radar, which is why an announcement is usually made for passengers to keep their seatbelts fastened, even when the airliner is flying in clear skies.

Airlines have Standard Operating Procedures for the pilots concerning flight toward an area of severe weather (e.g., a thunderstorm). Pilots typically ask for a course deviation so they can fly around the area or a change in altitude to fly above thunderstorm cells.

"Airline pilots and dispatchers dislike CAT more than any other weather phenomenon because it is difficult to predict and as a result, almost impossible to avoid.

Current turbulence predictive tools can give operators a general idea of where turbulence encounters might happen but can't specifically say if they will happen at all."

"Commercial aircraft report at least 5,000 encounters with severe or greater turbulence every year with most of them occurring above 10,000ft." (ref. http://www.aerospace-technology.com/features/feature44484/)

Flying is usually enjoyable and saves a lot of travel time. Statistically, it's the safest form of travel. However, thunderstorms are among the most powerful phenomena on Earth, which is why airline pilots are trained to avoid them by many miles.

The investigation team examining the crash of AF 447 may recommend changes to the way airlines operate in the vicinity of thunderstorms. Recommendations made after previous crashes have made air travel safer for us all.

Notwithstanding this and any other catastrophes that may occur, air travel remains the safest way of getting around by far.

This "journalist" just started an argument with "according to Wikipedia".... are you serious?? Wow... stick with the freelance writing, its the best gig you'll ever get.

After reading this piece, I have no idea why CBC turned down my article on the state of the economy. After all, I have over 75 (count them.... 75!!) whole hours of shopping experience, and happen to have Wikipedia bookmarked on my computer.

An absolute disaster. I've read the comments to date but I still keep wondering if the electrical failure(s) were caused by CAT circumstances themselves, and that the captain and crew simply and finally could simply no longer control the aircraft after losing electrical power and who knows how many other aircraft powers. My heart goes out to the families and friends who now have to live with this.

Hey Watson! Let Sherlock and the REAL detectives figure out what went wrong before you cause mass hysteria with your little theory. By the way, there are several if not hundreds of hypothetical possibilities that could explain why this plane crashed. My advice: wait until all the evidence has been gathered and pray that Watson isn't your pilot on your next flight!

In referring to the electrical malfunctions detected:
The CEO of Air France characterised these failures as a "totally unprecedented situation in the plane".

These electrical failures may have been one of the consequences of the catastrophic event, not the precipitating factor.
Severe damage to the airframe can be expected to play havoc with the aircraft's electrical systems.
The location and sequence of these electrical failures will doubtless help in creating some of the hypotheses to be considered during the investigation.
As an example,if the data showed a sudden interruption of power supplied normally on a continuous basis to an essential element in the aircraft, physical separation between the power source and this load would be an expected sequel to structural disintegration.
Beyond assuming that a bird strike was unlikely, it's just guesswork at this stage.

This whole senario seems strange.... why would experienced pilots willingly enter into a thunderstorm? This modern aircraft has equipment that can show bad weather, how come they didn't ask to deviate from course?

Another emerging hypothesis regarding the loss of Air France Flight 447 was that its altitude and airspeed computer, called the Air Data Inertial Reference Unit (ADIRU) had a software "bug" causing the plane to suddenly nose dive. This has already happened on other Airbus A330s, notably Qantas' Flight AF72. Initially, the computer software malfunctions, indicating the plane engines have stalled, so the plane immediately dips down. If the pilots don't regain control fast enough, the aircraft will drop at a rate capable of tearing the wings from the fusilage.
I'm going to avoid all A330 aircraft until this deadly glitch is fixed.

Whatever he says is one of the hypotheses that will be analyzed in coming weeks. What you feel from reading this does not matter. Ignorance does not make flying any safer. It is all about probabilities of encountering something which can overpower a plane and possibly combination of factors no matter how small. In a critical situation something normally small may become of great importance or distraction. Nature is powerful.

I think the Air Plane was shot down ...

if you study the situation carefully, you will see how key personals of a certain government was present at a University in Rio on that night.

I'm not a pilot but am a frequent flier. This story will inevtitably cause anxiety and I do wish peace to all of the parties who have suffered a loss. My own view is that the recovery of the black box will help us separate heat from light and that, in the end, we should trust the aviation experts to explain what the data shows. The speculation in this article is well intended but, in my view, is inflammatory and unhelpful. Not everything in life is explained in 24 or 48 hrs--so we wait and pray for all.

While I do not question the intention of the writer, it seems to me that speculation is futile, and unncessarily anxiety-laden, until we get data and aviation specialists analyze the circumstances of this tragic episode. In the meantime, God bless all who have suffered such an enormous loss.

I honestly believe its fine for fellow aviators to give opinions or ideas relating to the happenings of flight 447. If fellow aviators didn't give such explanations or thoughts then where would entities such as the NTSB and FAA be seeing as they are current and former aviators to a certain extent. Facts are facts and until they are present anyone can and will speculate as to what caused this unfortunate crash.

C-130 Hercules “Hurricane Hunters,” which are not structurally reinforced other than added fuel tanks for extended surveillance, fly into hurricanes. Whatever the Herc can handle the A330 can, including and easily, severe thunder storm and turbulence.

Today’s jetliners are strong enough to survive punishing CAT that can severely injure if not buckled up. These aircraft divert around storm fronts not to avert airframe damage but to maintain reasonable passenger comfort to avoid passenger complaint, potential law suit and negative press. With the most advanced weather reporting system ever A330 pilots know long before the first passenger boards where and what to avoid while en route.

They have the added benefit of onboard real-time weather radar and analysts back at company HQ in contact with the crew watching out for significant changes to current and forecasted conditions. A330 crews do not fly into towering CB at cruise level and CAT will not bring down any A330 unless in conjunction with aggravating factors such as unrepaired prior tail strike-related damage. The facts known so far do not support the CAT scenario.

The ACARS would’ve reported the data and there has been no confirmation that the airframe was severely tossed around. The ACARS reported abrupt electrical loss and then cabin pressure drop. The FDR and CVR will reveal a much clearer understanding of what happened. Lightning is a non-issue unless there's an engine fuel leak.

They may never find the black box from this plane on the ocean floor.

Would it not be possible to broadcast the live data stream recorded on board to satellites, land pick-ups or to other planes (they could record one another) so that we are not dependent on finding the black box to access that critical data? I know it would be a major cost to change it over, but surely this is the better way in the 21st Century.

I'm not flying again.
taking a ship in the future.

God Blest all the lost soles.

I agree that the experts will probably find out what happened, however this will take a long time as the debris is spread vastly across several miles of the ocean.
It is hard not to speculate, and I can help thinking about it.
In my opinion, the plane may have experienced 'rapid decompression'. It basically blew apart in mid flight, explaining why the debris is scattered and spread so far. Also, there was no 'mayday' or other correspondence with the crew.

Such decompression is caused by a major structural failure of the hull. While today's modern airplanes are well engineered there could be several causes for such decompression:
1. Metal fatigue of critical components/structure.
2. Turbulence/lightning so severe that the plane took structural damage.
3. Explosion of the fuel tank - maybe caused by lighting (unlikely but not impossible)
4. Explosion caused by any other source, maybe a bomb (since no 'group' claimed responsibility this is not likely), rupturing the hull.

Anyhow, I don't mean to offend anyone with my speculations, and I am eager to hear about the investigation.

In the meantime, my thoughts and prayers are with those that lost their loved ones - especially the children that lost their parents.

No expert with experience turns to Wikipedia as a source. Could we get someone who knows how to actually looks something up?

Immediately after I heard about the missing jet I checked the satellite photos and saw the thunderstorm clouds. I predicted myself this is where the plane encountered trouble and not to my surprise is what was later developing was that the plane went through intense storms. Well no kidding you could see them develop on the past satellite pictures. They should have immediately searched this area first, and I'm not so sure they did. Hindsight is 20/20 I suppose.

As for why he flew through the storms? He probably would have had to severely divert his flight path 50 to 100 km both directions to go around the storms so he chose to go through.

I think given the changing weather patterns and the increase in storm intensities, airlines need to adopt new protocols regarding storm conditions. Especially through the equator.

Recovering an FDR in 4000+ metres of water is not a trivial task. If the acoustic beacon is functioning and if the FDR is accessible (not buried under wreckage) and if the data are intact, it will be of great help.

Lightning strike should not be discounted, and it presents more of a risk than just ignition of fuel vapours.

On a military jet that had experienced a lightning strike in clear air we had both significant structural damage and a number of electronic systems that were damaged beyond function. That aircraft had been electrically hardened for carrier operations, and still lost several systems. While the FBW flight controls were left intact, there was some degradation of other flight-essential systems. The structural damage was to both metal and composites.

Lightning strikes are considered in aircraft design, but the results of a strike are still unpredictable (and highly dependent on what part of the aircraft was hit).

The sequence of fault messages will be an excellent clue in determining the progression of whatever happened (which we may never know for sure).

I agree with Waldo Pepper and I don't accept the CAT or lightning strike theory. The pilots would not have WILLINGLY entered into severe weather in the first place. I do agree with the theory that the aircraft experienced some kind of catastrophic structural failure, if we know that cabin pressure was lost. Unless the black box is found and a concrete conclusion is formed based on the evidence, this is not only a A330 issue, but an A340 issue as well since they share the most of the mechanical and electrical designs.

It is clear that the weather condiction was ablle to put the airbus down.

...of course the question that comes to my mind is: structural failure secondary to what cause? Versus the flight hours flown by A330 and 340 world-wide, catastrophic structural failure is not likely to just happen (as with the de Havilland Comet) from structural fatigue in routine flight.

It is a bit early to dismiss any theory that fits the limited fact picture. For example, how would a complete electrical failure impact the cabin pressurization system? What about a lightning strike causing mechanical damage leading to depressurization and electrical failure? If structural failure led to the electrical fault messages...how is it that system could still transmit data? It is difficult to do anything other than speak hypothetically about what might have happened.

You do not have to fly into a CB cell to experience either the electrical or physical effects of the storm. Particularly when attempting passage between CB towers you can experience both lightning and turbulence in clear air.

Hello Blair,
I don't expect this Blog to be posted due to it being out of context, however a High School friend and I got our licenses simultaneously in different geographical locations in the early 70's, Ted Briggs in Kelowna and myself in Abbotsford. I was wondering if you know Ted and/or his whereabouts? Last I heard was he was flying for Air Canada; this being about 20 years ago.

The black box should be found at any cost. The explanations of the pilots here about CAT sound trustwothy. Never heard about it before. Thanks.

I've been witness to a couple of examples of this in the last couple of months. There was a show on television last week that detailed an encounter on board a China Air flight that lost a significant amount of altitude somewhere over the Pacific in the last hour of its flight. I think that it was near California or Hong Kong. I can't remember it precisely. I was making dinner at the time and I wonder if it wasn't the same type of aircraft.

Before that there was a show about a US naval carrier on a routine training mission off of the coast of Cali. One of the Super Hornets was glitched by a lightning strike. There was a major electrical failure including communications. Fortunately Pilot was able to successfully land the plane at a field inland.

Thanks for this discussion. I seems to have brought out some characters for sure! Especially those with some insight.

It's hard to imagine how the families involved in this tragedy feel. I'm sure that God is wish them in this time of mourning and questioning.