T-Storms Blamed For Jet Crash

[Mike Krzywonski]

http://content.usatoday.net/dist/custom/gci/InsidePage.aspx?cId=honoluluadvertiser&sParam=30876113.story

[Chris Kennedy]

My prayers go out to everyone on that plane and their family members

[cdcollura]

Good day all,

This is why you do not fly through any thunderstorms / convective showers.

I remember speaking with a pilot, and he avoided anything above Level 3 VIP, Level 6 being the highest (above 55 dbz).

[Andrew Stoller]

Some news reports I've heard indicated these weren't garden variety thunderstorms either. They had tops over 50,000 feet and were quite strong.

I dunno; maybe lighting knocked out the electronics. This happened last night so if they lost their artificial horizon, then....

[John Wetter]

At the same time I've seen numerous interviews with pilots saying that Lightning shouldn't do that to planes as many actually get struck every year... Maybe it just has more to do with the strength of the storm they went in to.

[cdcollura]

Good day all,

I am not sure what they flew into / through, but I doubt it was anything really severe.

In that part of the world, over the tropics, and with little or no upper-air dynamics, strong storms do nothing more that just "wet the palm trees".

Flying through this stuff, however, is a different story. Tropical thunderstorms can be a very dangerous thing to fly through.

I remember flying back from Panama in 1997 and the pilit decided to punch one of those "small" tropical cells along the ITCZ. Nailed everyone in their seat at twice the pull of gravity for a few seconds (from the updraft), then nearly lifted me out, straining in the lap-belt.

Throw in something like this with a wire-chafing problem, or weakened structure, and then you really have problems.

[John Hudson]

I have doubts about the lightning theory, since so many safeguards are included in the assembly of aircraft these days. All movable parts like control surfaces and landing gear have bonding straps attached to complete the Faraday cage, and avionics are painstakingly isolated from the rest of the aircraft structure.

The only caveat to this would be if they had an unfortunate encounter with a positive strike, which would likely have changed things somewhat. Or, the lightning could have hit a surface made with glass or carbon composites, which don't handle lightning attachment very well and have a tendency to explode.

The last time an aircraft was lost to lightning (with proof) was way back in 1963.

I think I'd be more inclined to suspect that extreme turbulence loads or hail brought this plane down.

In any case, it's a horrible tragedy.


John
VE4 JTH

[Chris Carter]

well, from what i read in the stories, it wasnt lightning that may have caused the problem, many believe that because of the thunderstorm, but there was also severe turbulence and there was an electronics failure notice that was sent out before losing contact with the plane...in anycase, my heart and prayers go out to those families hurt by this tragedy.

[Oscar van der Velde]

GOES and Meteosat images of 00-03Z indicated that the likely thunderstorm cluster it reportedly entered was located 600-700 km farther away from the island of Brazil where they first started searching, near 30-33°W and 1-3°N (900 km from Brazilian shore).

[Dennis Dennison]

1st--R.I.P. All on board.
2nd--I seriously question composites for large airliners.
3rd---I seriously question Airbus design as far as computerization of controls-too much automation IS NOT a good thing.
4th---My bet will be an electrical/electronic problem.

[Oscar van der Velde]

http://www.cnn.com/2009/WORLD/americas/06/02/brazil.france.plane.missing/index.html

"Two debris fields were found about 650 km (400 miles) northeast of the Fernando de Noronha Islands, an archipelago 355 kilometers (220 miles) off the northeast coast of Brazil, the Ministry of Defense said on its Web site. The debris lies about 80 kilometers (50 miles) east of the flight path between Rio de Janeiro and Paris. " (right where the storm was located)

[Scott Olson]

Clearly from the lack of a mayday call it is clear that whatever happend was catastrophic. It was reported that the aircraft continued to send out 13 automated ACARS messages, in which it was reporting several electrical malfunction in many systems.

Turbulence- Turbulence is certainly possible as there have been numerous instances of severe damage to an aircraft from Turbulence, including engine seperation and seperation of a tail fin. These things however should not lead to widespread electrical failure or malfunctions.

Lightning- Aircraft are designed to withstand and distrubute the force of a lightning strike. You don't hear about cars being disabled by lightning even though there are millions of cars moving about in charged lightning fields every single day. Aircraft are designed with this in mind and despite all the problems it's nearly unheard of in the history of modern aviation for an airplane to crash due to a lightning strike. One possibility in my mind is that the we are talking about some type of jet, or other form of lightning that occurs towards the top of a thunderstorm and has properities and intensities that exceed the design limits. In that aspect It is certainly possible that a lightning strike could have severely damaged the electrical systems in the aircraft, or even perhaps lead to an explosion of some sort. To me that still leaves two questions. First, if there had been a completel catastrophic failure then why is the airplane still managing to broadcast the ACARS messages? Certainly some systems must still be online for the diagnostics to work and for the message to be sent out. Second, even with a complete electrical failure the A330 is flyable. The airplane is highly automated but it should still be flyable without the electronics. There are backup instruments that don't need electricity, also the engines should continue to run and the hydraulics should continue to have pressure. Even with the loss of both engines the aircraft has an APU that can generate functional power.

I think the most likely solution is some catastrophic break up of the aircraft. There is usually not a mayday call in the event of such an event (see TWA800).

Given the very long debris path, it unfortunately appears that the aircraft was torn apart over the course of course of 4-5 minutes.

[Scott Lincoln]

Given the very long debris path, it unfortunately appears that the aircraft was torn apart over the course of course of 4-5 minutes.

Or more than a full day of ocean currents and stormy swells have made their impact.

[Joshua Nall]

Tim Vasquez has written a piece on this and can be found at this address:

http://www.weathergraphics.com/tim/af477/

I was listening to Rush Limbaugh today while commuting between job sites and he mentioned to his audience that Tim's write up about it was excellent, and then he gave out Tim's website and the address to the document. I'm sure his website has seen a lot of traffic today :)

Sorry if the address above doesn't convert to a link, as I'm fairly new to this.

[Rob Sermon]

Lightning has nothing to do with this aircraft accident. I've been struck in a Cirrus SR-20. The immediate failures were the Primary, and Multifunction displays, which after reboot worked fine, with the exception of the glide slope indicator. (insulator got fried)

I figure the flight got into a "hot tower" (a Cumulonimubus, busting 50,000 feet) and got her feathers torn off.

[Chris Carter]

Some experienced pilots are saying that no pilot would dare attempt to punch through a thunderstorm of any kind, but some of them try to fly around the tops and sometimes can get caught in a updraft, this may have happened as i read somewhere that there was estimated 100mph winds within the storms.

[cdcollura]

Good day all,

Updraft speeds in a "hot tower", defined as any deep tropical thunderstorm which involves convection from the low level (boundary layer) up to and even exceeding the tropopause (50,000 - 60,000 feet). This is common with tropical cyclones as well.

Updrafts in these storms are anywhere from 50 to 100 MPH. In comparison, a supercell storm can have updrafts exceeding 150 MPH! With that, these updrafts are also "bounded" next to strong downdrafts as well, that means, if a plane is caught in a 80 MPH updraft, then suddenly flies out of it into a 80 MPH downdraft, the "shear" experienced by the plane is 160 MPH ... Loads induced SHOULD tear any non-fighter-jet type plane apart.

No commercial aircraft

[Anthony Petito]

http://www.time.com/time/world/article/0,8599,1902421,00.html

Found a Time article that references past findings on A330 and A340 models having issues with Air Data Inertial Reference Units (ADIRUs) and how the flight computer interprets/responds to data presented to it by these units. A330/340s have 3 of these units on board that help feed data into the flight computer. These units esentially feed the computer the data needed to keep the plane flying when autopilot is initiated. The flight computer algoithm is designed to gather data from all 3 units, however, it was also designed to throw out what it would consider "bad" data from one of the units. Instead, relying one the other 2 for accurate flight data.

It seems in past instances, the flight computer instead did the opposite by listening only to the ADIRU that was feeding bad data in the flight computer; which, in turn, caused the computer to immediately dive the plane. I'm not an expert, but in the instance references by Time, the flight computer responded to an ADIRU unit that reported lack of air over the wings, or measuring it's angle of attack (AOA). The response for such an event would be to dive so the plane doesn't stall.

After reading Tim's analysis, I would be intereted to see what would happen if the plane, flying at ~FL350 suddently dived below FL200 or lower. Depending on how deep the dive is, would there have been time for a mayday call? Would ice become a factor? Could the developing storms have produced enough shear to rip a plane apart?

I'm sure the weather played a pretty significant role in the crash, but my guess is that other events are at play here and the weather didn't do anyone a favor.

[Ryan Moats]

Well, through past events, being a pilot my self, i'm gonna suspect electrical fire
since fire seems to be the only thing in many past crashes to have slowly/quickly take out many electrical systems and overwhelm the plane.

The Swiss air flight, Valu JEt, etc which all went down because of a fire which slowly took out all electrical systems then flight controls and overwhelmed the plane.

Turblence, HAHAHA, no way did that take down the plane and especially nor did lighting. Check up the the 747 Evergreen jet that took off from alaska.

Almost every plane is struck by lighting and trust me, planes are DESIGNED to not be effected by lighting. Half the time, a plane gets hit and they crew doesn't even know it.
There are too many safegurads and redudant systems for just simply lighting to take out a highly advance jet liner.

My theory, Turbulence knocked around something causing whatever to start a fire. The fire slowly burned through the electrical system taking maybe the radios, avionics whatever first and slowly burning through the rest of the vital electrical systems which in turn power the flight control systems which and caused the plane to be doomed.

This would explain the messages being sent out before the messages stopped about electrical system failure. As the fire burned, it didn't burn the instrument wires to the device that monitors the electrical systems until the fire burned through the electrical part of that device.

A fire slowly kills power to each system on by one until overwhelming the plane. It could of take out the radios first or the Mayday never came from the pilots because where they where in the ocean, might of been no radio coverage. Hard to say.

We shall see over the next few weeks.

[Clarence Bennett]

Anyone see the Piece Dr. Forbes did on TWC? Was pretty basic and brief, but it seems to have shot the theory of lightning or updraft/downdraft all to you know what. Made sense to me. If they ever find the boxes, there is going to be alot more to this story I believe.

[Jay McCoy]

It depends on who you believe expert wise as to whether the plane broke apart or not. I dont buy a fire or lightning strike. New aircraft like this have very good fire suppresion systems and a lightning strike wouldnt cause loss of cabin pressure.

According to actual air safety experts and people from the airlines that messages sent from the plane indicate the plane was breaking apart in flight due to violent storms which jives with Tims great analysis.

http://www.foxnews.com/story/0,2933,525043,00.html?test=latestnews

If you read a report using Brazil's 'defense minister' the oil slick being in one place means the plane didnt break up. I dont give alot of credbility to a defense expert over people who actually fly or designed this aircraft or are aviation experts. Also the fact that automated messages indicated loss of cabin pressure and 2 seperate debris fields have been found so far indicating to me the plane breaking apart. If it came down in 1 piece then why 2 seperate fields?? Its amazing how the media can come to a conclusion using 1 "officials" comment when he isnt even in the aviation field.

http://www.cnn.com/2009/WORLD/americas/06/03/france.plane.memorial/index.html

[Anthony Petito]

If you read a report using Brazil's 'defense minister' the oil slick being in one place means the plane didnt break up.

I guess it depends on what they found in the debris field with the oil slick. Most of the fuel is stored in the wings and a center fuel tank that site between the wings in the lower hull of the aircraft. There's also a smaller tank in the tail section as well.

It could be that's where that the oil click they've found is where the either the tail or center/wings area of the plane fell.

The problem is that both Brazil and France are releasing conflicting reports. 1 says there will be no survivors while the other is holding hope, one says the plane was struck by lightning, the other says severe turbulence and no conflicting reports about what they're finding. It doesn't help matters when the US Media picks and chooses things to report and runs with it.

*sigh*

[Jay Bell]

Alright....

I'll chime in here. Having been a professional pilot of over 15 years ( read commercial/airline) and having flown over 21 years now, I can dispute the lightning myth completely. I have been struck in commercial aircraft over a dozen times....and NEVER lost anything that was critical to safe flight. Lightning does not "fry" entire electrical systems, or cause loss of pressurization, or any of the other issues reported to have occurred on the A330. What it does do is this...It creates structural "burn" damage. What i mean is this...there is, in general an entrance point and an exit point. These areas CAN create weak spots in aircraft skin (whether aluminum or composite) as well as can do damage to an individual component that is not properly grounded to the airframe ground. In fact, most times you don't even know you were hit until a maintenance inspection sometime later.

I don't like making conclusions or assumptions about an accident until all the facts are in. There is usually not one single "smoking gun". It is always a chain of events.

Let me give a scenario. Assume this aircraft was flying in the region of adverse weather at an altitude of, say 35,000 to 37,000 feet. This would be normal for this aircraft. Many have made the assumption that pilots fly around the worst thunderstorms (I read a few posts back "above level 3"). This is a very true statement. However, there is a problem with this in that airborne weather radars do NOT work well above 30,000 feet. Why? Quite simply because precipitation is frozen above this level. When the radar is tilted towards the surface, it paints only the precipitation core (and nearer the surface) but NOT the updraft region...which most likely is not the same area at that altitude. Now, if you are flying at 37,000 feet and in the clouds, you may not be able to visually "see" a 50,000 foot TRW. So, unless the radar is tilted far enough down to paint the lower core areas, it may never be seen until too late.

I have, in the past, inadvertently entered weather I wished I had not. Having said that...I could see how this accident "might" have transpired.

The idea has been implied that this aircraft was somehow "weaker" because it was made of composite materials. Truth be told, composite aircraft are somewhat stronger than aluminum framed aircraft. The A330 incidentally is only composite on the skin, and has an aluminum frame.

In any event, if indeed it was a thunderstorm encounter, supercell, or not, a storm that reaches 50,000 feet WILL bring down an airliner. It has happened before, will happen again, and "might" have happened in this event. Airliners are approved to FAR 25 standards which essentially design the aircraft for an operational limit of 2.5 g's and a maximum somewhere around 4g's (I believe). Military aircraft have experienced upwards of 8-10 g's in the updraft region of a thunderstorm. So, based on this, you can see even an airliner is no match for ma nature.;)

Jay

[cdcollura]

Good day all,

Excellent post, Jay ... And quite interesting.

The radar is misleading as "hydrometeor" sizes are also smaller, and ice crystals present very poor returns on radar displays. The SPEED of the air, however, moving up /down is a problem, and not necessarily reflected on what the radar "sees" at that height. A level 3 (from 1 to 6 VIP) storm at 35,000 feet is ALOT, and the question is what "level" will that same storm be just above MSL?

Second, I beleive all general aviation aircraft have a MAXIMUM load of 3.8 G's (4.3 for utility).

These G limits are way below the G forces a thunderstorm core encounter will present = Possible catastrophic failure.

[Chris Carter]

Hey, just a quick question here, werent they flying at night?

[Anthony Petito]

Hey, just a quick question here, werent they flying at night?

Yes, I believe it was about midnight local time in the area where they crashed.

[Jeff Russell]

Be careful when stating G load limits. Most limits are for safe flight. Limits experienced beyond those does not mean a failure will occur. Aircraft manufactures do jig test on test beds to determine actual loads were failure will occur. Search youtube and I'm sure you can find a video of this procedure. You will be amazed by how far the wings can bend upward before failure!

Jeff

[Jarrod Cook]

Interesting scenarios and commentary here. However, I think more focus should be placed on the in-flight depressurization. Sounds like it broke up one way or another structurally. They seem to want to rule out an explosion too due to so much fuel and oil found on the ocean surface. The fire theory sounded good, but would this cause rapid depressurization?

Unless they find the data recorders, we may never know truly what happened. I'm surprised so many underwater searches have taken place and *now* they are finally interested in designing floating "black" boxes.

[MClarkson]

I would think it is *possible* that an extraordinarily strong bolt of lightning managed to take out all or enough of the electronics that control the plane.

Of course it is possible that turbulence damaged the plane enough to doom it, perhaps in combination with improper crew response when entering turbulence.

While you probably wont find a pilot charging into the core of strong storm very often(although it happens by accident sometimes), you will find airliners routinely flying through the fringes or very close... Usually you can get away with it.

[Greg Campbell]

Today's big news is the recovery of the intact vertical stabilizer. It appears to have been sheared off at the base. Does anyone know if the victims were found in the same vicinity? If not, it's sure tempting to imagine that the tail broke off, causing the depressurization warning and subsequent crash. (I know this is an unjustified leap.)

[Dennis Dennison]

Judging by Air France move to replace sensors--and the finding of the tail in one piece, and reading all the automated failures that came from the aircraft--I still think and electronic failure happened.
I think they will find (Maybe) that a sensor failed-it began causing computer problems related to the FMC/Autopilot--They claim the autopilot was shutdown-either ny computer or manually-and some sort of rapid climb began to take place.

I am thinking the autopilot was told to shutdown by a computer misread of the speed-resulting in a pitch up, stall and then a dive which resulted in exceeding red line and breakup prior to impact.

In any event--I rather doubt they will ever resolve it, those black boxes are going to be really hard to find

[B. Kotcher]

Yeah, an article in the paper said that if the rudder is deflected far enough at high speed, the vertical stabilizer will shear off, so the aircraft's computer constantly checks airspeed and keeps the pilot from deflecting the rudder dangerously far. If there was something wrong with the airspeed sensor and/or the electronics, and the plane was flying much faster than the computer and pilot believed, the pilot could have input enough rudder to cause the vertical stabilizer to shear off, which would cause the plane to crash.

--Bob

[George Limpert]

Under normal conditions, Airbus planes operate under normal law. This means that the computer allows the pilot to disengage the autopilot as desired, but the computer still prevents the pilot from doing something unsafe.

Inputs from sensors are constantly verified and if the computer detects invalid input or some other system failure occurs, those systems are disabled. This is referred to as a control law reversion. In that event, control would have been returned to the pilots in alternate law, in which many of the protections normally enforced by the fly-by-wire system are disabled. Should additional failures occur, the fly-by-wire system will disable those protections as well. It is possible for that to happen and for all protections to be disabled, which is referred to as direct law.

If control was returned to the pilots under alternate law, the pilots may simply not have had enough information to react safely. They were also flying very close to the "coffin corner," which is where the stall speed and the critical Mach number are equal. Stalling or going into Mach tuck both would cause a loss of altitude that could eventually lead to a structural failure.

Under those conditions, it wouldn't have taken much to cause Mach tuck to occur. A gust of wind could cause that, which is not at all unlikely under those conditions.

While that doesn't explain what caused the autopilot to disengage and the system to revert to alternate law, it's a plausible explanation of what might have brought the plane down.

[MClarkson]

The finding of the vertical stabilizer more or less intact doesn't strike me as particularly significant by itself. The plane could have broken apart in the air from aerodynamic stress after it lost control(for whatever reason), with the separation of the vertical stabilizer being the result of, not the cause of, the crash. Also if the plane did impact the water more or less intact it would have separated then. Sections from the tail are often the largest or most intact debris that remains.

[Mike Krzywonski]

Autopsies Suggest Plane Broke Up in Sky :

http://news.aol.com/article/air-france-jet-crash/520205?icid=main|main|dl1|link3|http%3A%2F%2Fnews. aol.com%2Farticle%2Fair-france-jet-crash%2F520205

[Stuart Robinson]

Does look like a plane brake up - poor souls

http://uk.news.yahoo.com/5/20090618/twl-jet-victims-injuries-give-clues-to-c-3fd0ae9.html

: "Typically, if you see intact bodies and multiple fractures - arm, leg, hip fractures - it's a good indicator of a mid-flight break-up.

"Especially if you're seeing large pieces of aircraft as well."

Aviation safety consultant Jack Casey agreed multiple fractures were consistent with the plane breaking up in mid-air and that the lack of clothing could be significant.

"In an in-air break up like we are supposing here, the clothes are just torn away," he said.

[cdcollura]

Good day all...

http://www.sky-chaser.com/image/stplog/p061909a.jpg

Just had to throw this one in (Miami airport)...

Lightning is the LEAST of a commercial airliners' concerns although an airliner and lightning encounter is both frightening and ominous. The "faraday cage" effect, as well as lightning's current flowing AROUND the plane's metal skin and not through it makes these planes safer.

Turbulence and / or icing, on the other hand, is something very few airplanes can handle inside a thunderstorm.

[Toni Scholz]

As with most airline disasters; a chain reaction of failures is to blame. The backup systems and fail-safe designs that these modern aircraft have are designed to operate when there is a single failure within the given system. The problem is when multiple failures occur across systems that lead to a catastrophe that can't be avoided.

The findings will likely reveal that a number of factors contributed to the disaster. The air speed sensor failure in itself wouldn't have been a fatal flaw if it weren't for the specific weather conditions they encountered and so on. Unfortunately, understanding the causes will not change the end result.