It seemed to be a pretty good write up intil I read this bit of wisdom:

Odd ...
 

There's something that doesn't quite compute here ... 4 minute long communication via ACARS, yet over that the same 4 minutes no PAN or Mayday on either 121.5 or 123.45. It's clear you navigate before you communicate, but 4 minutes do sound quite long.

Also - due to the altitude where the initiating event took place (FL350 from what I've read) the debris should be scattered in a rather large area if it would be turbulence and structural break-up (and those 4 minutes of ACARS messages speak hightly against turbulence and immediate structural breakup). Loss of control and structural break-up either at a lower altitude or upon impact :ouch: sound more likely.

Disclaimer: not a pilot, just an enthusiast working where I need to use logic and deduction.

Agreed, im sure with those conditions, the bunk would be the last thing on his mind!

No, my friend, Airbus doesn't know what happened on this flight but it was conveniently blamed on the copilot because he was there and had a lot less money to sue then Airbus. It is just the way it works. Just convince the public.

ROV's
 

These people may be able to handle a deep search.

Oceaneering International; Inc.

Reuters latest
 

Doubts over lightning's role in missing jetliner

Brazil said Monday's aircraft last made radar contact at 0133 GMT after passing the Fernando de Noronha islands off its northern coast, about 250 miles (400 km) south of the equator.

It was heading towards a notorious stormy patch that shifts around the equator known as the Intertropical Convergence Zone.

It had been preceded safely on the same track 30 minutes earlier by a Boeing 747-400 heading to Frankfurt for Lufthansa, according to a source with access to data transmitted from jetliners for the World Meteorological Organisation.

Two hours later an MD-11 cargo plane also flown by Lufthansa passed just south of the same spot on the way to West Africa, the source told Reuters, asking not to be identified.

Neither aircraft reported any anomaly.
"You can't tie it down to lightning with the information we have; for me it's a red herring," said the source, who specialises in aviation weather. Lufthansa declined comment.

CIRCUIT FAILURE

An Air France captain operating on long-range routes, who agreed to speak to Reuters on condition of anonymity, said lightning alone was unlikely to have caused the presumed crash.

"I would not think it was possible that lightning could lead to a short-circuit and disrupt all of the plane's electrical systems. Test planes have resisted some 30 lightning strikes and nothing ever happened," the pilot said.

More likely, he said, is that the jet might have suffered an electrical system failure which would have turned off its radars and communications systems, turning it blind and making it more vulnerable to storms and strong lateral air currents.

Prima facie, a constant stream of telemetry is not a bad idea, but I imagine the practicalities (and I know nothing whatsoever about it!) would consign this to the "too hard" basket?

This accident made me think about the A330 incident in Oct 2008...

"The Airbus A330-300 was flying from Singapore to Perth when it suddenly plunged thousands of feet, leaving more than 50 people injured.

A computer malfunction involving the auto-pilot system was blamed for the incident"

Is there any possibility that something similar to this has happened too?

Whatever tragic events occurred--no question it happened fast--probably instantaneously. With almost instantaneous communications capability via SATCOM and ACARS available on this aircraft, the fact that (as far as we know) AF Paris flight dispatch heard nothing from the crew themselves prior to the event suggests whatever the issue, things deteriorated very quickly...so quickly that the crew could not contact/advise CDG dispatch...it takes no more than a few seconds to hit the CDU and send dispatch a msg via ACARS.

One thing that comes to my mind with this tragedy is the Qantas A330 events in the past months, where the ADIRU apparantly cause very sudden/abrupt flight control movements. The one flight that landed in Exmouth suffered alot of airframe damage as a result of the sudden movements. Although some suggestions point to possible naval radio interference on that incident.

This is a very disturbing situation, as the a330 has a good safety record, although the QF incident comes to mind, and with a violent pitch change at high speed in what has been said severe turbulence could likely result in structural failure. Given the little facts at this stage perhaps it`s hard to even speculate, but a cockpit/electrical fire is also a possibility

http://www.hcl.dk/graphics/synkron-l.../67-00.GRL.pdf

Even though it is very rear, lightning can cause an onboard fire!!!:uhoh:

We have around 10 automatic technical messages sent via satellite from the aircraft to the Air France maintenance center. All these messages relate to some sort of deterioration or failure regarding the avionics and electrical circuits. The duration of this event is about 4 minutes.

Engineers at Air France in my view already have a lot of information in terms of events with these messages.

Air France CEO, Pierre-Henri Gourgeon states that the above messages denote "a situation totally unexpected, totally unprecedented in the air and a great difficulty."

Carnivore was an e-mail scanning system.

American electronic signals intelligence in space is operated by the National Reconnaissance Office. Their satellites, currently the MENTOR series, are extremely capable of detecting and recording radio traffic.

However, if the only transmissions sent from the aircraft were the ACARS bulletins already received in Paris, which seems probable, that would mean the satellite would not be able to provide any new information.

While lightning strikes are common, most of them occur near the freezing level, and not at flight level altitudes.

Lightning has a mind of its own, and for example will hit wiring in the wing root, as well as the fairing and the fuselage-wing spar joint.

Yes, weather radar is primarily a rainfall detector, and ice is a poor reflector of radar energy. That's why any radar return at flight levels has to be taken seriously. Modern Wx radars are equipped with doppler shift detection, which shows areas of turbulence, if there is the least amount of aerosols to reflect. It will not detect turbulence in clear air.

GB

I´ve flown on this route, Brazil/Paris Charles de Gaulle/Brazil, for ten years, with the A330-200 as a captain. Comunications within this area specially on the boundary between Atlantico and Dakar Centers, and specially with this last one, are very very difficult. And the worst nightmare possible in this route is an airplane coming down in the middle of the atlantic ocean, the area where its believed to be this aircraft. The logistic to do, and to complete the rescue, I believe will take a few days or even weeks.
My opinion is that something very serious happened, concerning the integrity of the structure of the aircraft, and or of the crew, and the thunderstorms may be just a contribuiting factor, for this tragedy. For sure, everything that could have being done, was done by this crew:D

Qantas A330
 

Previous post had:
Air France CEO, Pierre-Henri Gourgeon states that the above messages denote "a situation totally unexpected, totally unprecedented in the air and a great difficulty."
This is so like the situation with that Singapore-Perth A330 QF flight and the auto-pilot malfunction leading to steep uncontrolled climb then steep descent. Subsequent emergency landing revealed stresses. Computer systems failure seems to be to blame. You have to wonder if this is a similar, mysterious occurence. The full interim report makes fascinating reading.
200806143

MD-11 and 747-400
 

{Heavy} Lightning could be the issue with the missing airbus.
Both airplanes crossing the same area earlier and later (MD-11 & 747-400 see previous post)
have less CF in their structure and surface area. Energy will flow in all directions and are likely
to cause less damage. US Navy had freak incidents while testing CF wings years ago.

In-flight upset A330-303 VH-QPA, 7 October 2008
 

Thousands of feet? Absolutely not. From the Australian Transport Safety Bureau Interim Factual Report:Peak g loads during the upset were +1.56 g and -0.80 g. Subsequent examination revealed no structural damage to the aircraft. It is possible that a similar ADIRU problem could result in a substantially more difficult upset that the crew were unable to recover, although following the accident discussed here, Arbus sent out Operations Engineering Bulletins to all operators with potentially affected aircraft, detailing what to do if the problem occurred.

@ stebern
Thanks for sharing, seems interesting.
On QF72 the events do not seem to have an external cause though.
With AF447, the aircraft entered an area of severe turbulence around 2:00am GMT. 14 to 15 minutes later we have this 4-minute interval of technical bulletin transmission, all dealing with malfunctions and/or failures, especially electrical.
We have all reason to believe that, in between, there has been at least one external cause that may have contributed to alterate the flight integrity.

Like this for example?

That seems to be a marine one, I think, but I seem to recall reading of at least one air version with similar capability. The difficulty being to assure it'll be able to float out of what might be a seriously compromised structure. Also, in the event of a break-up midair, I'm not sure an ELT would necessarily survive the fall from x thousand feet and still be float-capable.

edit

OK, here's an Aviation ELT of type AD - Automatic Deployable

Now that's a helicopter version, but I'm sure there are fixed wing types too.

Search for wreckage
 

For those doubtful about recovery of wreckage and recorders, note the successful recovery of some wreckage and the CVR from the SAA Flight 295 that went down in over 5 km of water in the Indian Ocean over 20 years ago. For a good summary on the location of the wreckage two months after the crash from a large search area with the technology available then see HelderbergSearch Paper

There seem to be two translations of what the TAM crew saw - "flashes of light" and "flames on the ocean". The second seems more probable (if it was the AF flight and not just ITCZ lightning) since it was 30 minutes after the last transmission. And that tends to indicate the plane was still intact enough to be holding fuel in liquid form when it reached the surface.

Fuel dissipated in an aerosol at altitude would not burn in pools on the water.

In fact (well, OK, in speculation) it might even mean the plane was somewhat under control all the way down, and just had disastrous luck with a ditching attempt.

I'm more sanguine now about the odds of finding the CVR and FDR, between the TAM sighting, the Senegalese statement, and the French experience at undersea work.

I would not assume that a lightning strike directly destroyed this craft, but can easily see scenarios where it left them blind and/or disabled and easy prey for a subsequent event - TS penetration or control/instrument failures.

Speculation is what humans do - try to solve mysteries on insufficient data. With time the data become firmer and the speculation more narrowly focused - until eventually someone can write a report. Which, absent survivors, is still sometimes only a best guess as to exactly what happened.

we are never going to stop people from speculating in these threads any more than we are going to stop posters from expressing condolences to unknown readers. So we might as well give up trying to stop these expressions.

The professionals among us know enough not to give any credence to a speculation that jumps over several layers of swiss cheese effects to guess at an accident's cause.

On CMC and ACARS
This system can be very customized. AF knows much more than they admit. They have been talking to their legal team right from the start. They will spoon-feed us the info when they are told its ok by their lawyers.

On ELT
It's high time we have in the Airbus cockpit an easy access manual "on" button for the ELT in the back, like some Boeing models I flew had. If it was there...

On AF SOP
Was the Captain in the cockpit at the time or he was taking his rest? Who was in his seat - the guy with 800h or the guy with 2600? Not that it matters so much, but in an extremely stressful sit, it will won't it?

WE WILL KEEP WRITING THE DARN MANUALS IN OUR OWN BLOOD



:suspect:

:mad:

Similarities to KQ 507
 

Looks pretty similar to KQ 507. It also went down during turbulence. .....Lightening was sighted as possible reason. wonder what was derived out of the flight recorder of KQ 507. Hopefully AF will do a better Job !!!!!:\

Indeed.

On the subject of ELTs...
Most airliners these days seem to have top fuselage-mounted VHF/UHF ELT transmitters which activate under high g-forces (dedicated shark fin type antenna outside, battery-operated transmitter inside). These are now compulsory in some regions. I assume satellites have the ability to pick up their UHF signals. However, I seriously doubt their ability to transmit underwater (as claimed here). Radio waves do not propogate very well in water ;) Water is the realm of short-range ultrasonic transmitters mounted on the front of the very heavy "black boxes" (which definitely do not float).

Whilst creating ELT's that detatch and float is not beyond the realms of possibility, the mechanisms allowing them to automatically eject from pressurised aircraft on or prior to impact would probably be more more harmful to human life than beneficial.

On the subject of lightning strikes ...
People claiming that lightning can't bring down modern aircraft are treading on very thin ice. There have been fuel tank fires, total glass instrumentation failure, holes punctured in composite materials, etc, which could quite easily lead to aircraft loss (with far fewer holes than James Reason's model).

On the subject of ACARS transmission ...
The fault reporting system can be programmed to do whatever is desired (including position data, instant fault data, etc). The ACARS system has access to as much data as the flight recorders (if not more).

Anyway, let's hope the moderators have enough patience to get rid of all the chaff... and perhaps correct a few of those embarrassing spelling mistakes that so-called professionals seem to make (e.g. "loosing"(sic)), perhaps making PPRuNe more publication-worthy :}

Of all the idiotic drivel I have read in the press about aircraft accidents, this particular paragraph (from the New York Times, no less!) had got to take the cake:

A loss of cabin pressure could suggest a break in the fuselage, but planes are built to withstand buffeting from a storm’s updrafts and downdrafts. It could also be a consequence of an electrical failure, if the plane’s air compressors stop working.

The authors of the above gem truly deserve recognition, here are their names:

Donald G. McNeil Jr. reported from New York, and Christine Negroni from Greenwich, Conn. Reporting was contributed by Sharon Otterman and Micheline Maynard from New York, Caroline Brothers from Paris, Alexei Barrionuevo from Buenos Aires, Brian Knowlton from Washington, and Andrew Downie from São Paulo, Brazil.

Swish - the Airbus fleet at EK has manual ELT switch on the overhead panel just for your info...

I doubt an engine was the problem and would not need to be salvaged.

I agree. Bits of the Air India terrorist crash were recovered from mid-Atlantic were they not ?


Quote:
But we already have evidence of the captain reporting serious turbulence to base. Why, is another matter.


Well, he's talking out of his bottom then.

http://www.google.com/search?client=...utf-8&oe=utf-8

Unless he doesn't consider helicopters as 'aircraft'.

It would have to be a pretty severe event for an aircraft to breakup from turbulence. After spending most of my time flying in the tropics during wet season buildups and storms I have a fairly good idea of what an aircraft can handle. From flying around in these conditions in single engine Cessna 210 type aircraft to operating in the soup with no weather radar fitted flying BE58 and PA31 single pilot I.F.R. Now I fly multi engine turbine aircraft multi crew at fight levels quite often in the middle of it. I think we should give the aircraft more credit for being most capable in these types of conditions.

If its an electric fault, I would assume that would be because the generators were not providing current which makes me wonder in turn if the donks were turning the generators to supply the current. The biggest hazard around severe weather is not in my opinion lightning or turbulence for that matter but severe airframe icing and hail, as attested by recent events in the states and double engine failures in the past.

Whatever the cause, my thoughts are with the family's of not only those involved in the accident, but those of every aviation family with a partner and rug rats at home. We as an industry do not need something like this, especially now. I just hope the victims families get the closure they deserve and this whole affair does not become a media circus as attested by swine flu and the GFC.

GG

GPS position reporting system
 

One question from an electronics engineer. I understand that most problematic element in any security enhancement, or indeed any change in aircraft design, is mostly centered on extensive testing that is required on one hand, and the need for it to be integrated in an already extremely complex system. However, if we add system that is very small, autonomous, and only physically attached to some external part of the aircraft, than the cost and time necessary for its introduction would not be so big.

It would be very easy to add external device with internal GPS that can send aircraft position every 5 minutes or so over its own satellite uplink. It would need only power from the plane, nothing else. No attachment to any other aircraft system. No plane would be lost ever again, anywhere. Rescue effort can begin immediately, even at the first hint of a problem. Some lives would be saved and psychological problems of relatives and possible survivors would be much easier. No survivor can feel that he is lost or abandoned for the moment. It’s that easy. Technical problems are insignificant, cost of the unit also. No significant change to aircraft needed. It is not necessary to calibrate it, control, or maintain. It is simply kind of external, autonomous satellite mobile phone with included GPS attached to whatever part of the plane is most easily adapted for that purpose.

Is it possible to implement something like that?

Just a general query (never seen this arise before):

Purely hypothetically, one is just quietly driving along in the middle of the night in the middle of ANY major ocean and one sees flames on the ocean.

Is there any protocol? If there is sufficient fuel and weather permitting, does one investgate, i.e. circle or reduce altitude?

Who or what makes protocol for this sort of thing?

mike

PaleBlueDot
Aircraft are already fitted with exactly such a device, it's called an ELT. Although it doesn't report it's position constantly it is designed to start transmitting in the case of a catastrophe.

Michael, most probably. It might be an oil rig simply venting gas, so you would check your charts. It might be a tanker on fire, so you would check your radar. It might be a meteor or a satellite, so you might note and observe and consider diverting to search.

I think PaleBlueDot is referring to something more like the ADS-B system. I hope it becomes more common or even mandatory for all flights outside radar coverage.

ADS-B.com

To Mike Hammond,

I would suggest -
Report the event to ATC with exact position, any additional references, or observations...incidental additional info...e.g. appears to be a ship ...relative posn...to 'flames' or whatever.

It has been known for a flare to be sighted by an airliner - a pax in one case, referred to crew, reported to ATC, SAR notified, and an eventual 'happy ending'.:ok:

This gets to the point of why we still have to use such an old device as HF radio for postioning reports when we all know that we can use our aircraft phone and call OPS or report an emergency for less than 1$/minute. I don´t like flying with no communication, specially in the middle of the any ocean.

Take in mind that HF comm is highly affected by thunderstorms and lighting, probably they tried to call but no answer, shouldn´t be mandatory to have installed a worldwide comm device to communicate on any guard frequency? We are in the electronics era!!!!!

if there is an electrical failure or problem if i am not mistaken the RAT would deploy. RAT would power some crusial sustems in order for the pilot to have some sort of reference. I am not an airbus expert but just thinking out loud.

#338

Misd-agin;
Precisely. Works every time - "manual" calibration at the highest sensitivity then back off to the setting before "auto".

Antenna tilt is crucial to building the whole picture of what's up ahead - of this, more in a moment.

For the general information of the majority here who don't fly or don't fly heavy transports or the route under discussion it is important to understand some basics about radar, specifically the A330's.

To put it more succinctly and clearly, the following is offered to SLFs and other interested individuals who do not desire to second-guess any accident crews' decisions in advance of the facts or posit theories based upon guesswork but who instead seriously wish to learn, and who may wonder what radar techniques are routinely used and what radar can and cannot do. The following is standard equipment in an airline pilot's toolkit and is, or should be, unremarkable in terms of knowledge.

I am referencing ONLY the A330 radar here. The knowledge/statements are for information only and are not definitive. That's what the AOM and your company's MANOPs are for. A lot of this comes from Dave Gwinn's "How Radar Works", as well as just plain experience.

First, it should be understood that reading the radar signal is somewhat of a practised art and, like reading DFDRs and QARS requires some experience before interpreting the signal can be done well.

The proper use of digital, flat-plate radar requires an understanding of the nature of the signal and practical experience to interpret the returns with accuracy in order to plan a route through a line of thunderstorms or how much to avoid a thunderstorm by. The reasons for this will become clear.

Radar only senses (returns signals from) water. Radar does not detect "clouds" per se because some clouds, especially high ones do not contain moisture but only ice crystals which reflect radar signals very poorly.

Radar does not detect snow effectively enough for use/avoidance. I believe radar detects super-cooled liquid water but I cannot reference same in anything I've read.

The techniques for use of radar when pointing the antenna above the freezing level are different than when pointing below the freezing level.

Radar cannot detect CAT, (clear air turbulence - even if there is a 'doppler' mode on the installation - I've never seen that mode work successfully - anyone?). Radar may detect ice crystals but very poorly. Radar is not used to detect other airplanes or birds.

The A330's radar return is presented digitally in 3 colors - green, amber and red. I cannot quote the density of moisture which returns each color. Crews are advised to avoid anything in amber.

Radar returns can seem to exaggerate moisture content close in, (40nm scale and smaller). What can look "serious" on the 20nm scale can reduce or disappear on the 80nm or 160nm scale.

Avoidance:
A rule of thumb, (and it is only that), is to avoid strong (red) returns by at least 10nm found below the freezing level and 20nm above.

Signal attenuation:
Thunderstorms being seen on the radar can block thunderstorms behind those returning the radar signal until one is either past, over (not bloody often!) a thunderstorm, or the thunderstorm is dying and gets out of the way of the next ts's in line. Picking one's way in a line of ts's is difficult work in a rapidly changing environment.

Radar antenna tilt:
The A330's radar is IRS-stabilized so regardless of the pitch attitude, the radar is always "level" with the horizon, (in quotes because, to be accurate, there is more than one definition of 'horizon'. But practically speaking, at zero degrees tilt, the radar is pointed to the horizon we normally see regardless of pitch attitude.

The A330's radar beam is about 2.84deg wide, (3deg for all practical purposes - same with the 340 and 320 I believe - check with the AOM). That means that antenna tilt must be used frequently to scan up and down for moisture which indicates ts activity.

The 1-in-60 rule can be used to guage a rough altitude of the signal being returned by moisture, which, depending upon it's shape, (hooked, curled, tightly-banded with amber/red etc), indicates convective activity.

A quick calculation for a very rough altitude at which the radar's beam center is pointing is given by the formula, antenna tilt x distance (on the radar screen or, in the case of the A330, the ND scale) x 100. For example, at 1deg down-tilt, the center of the radar beam at 80nm in front of the aircraft is 8000ft below the "horizon", (practically speaking, "below the aircraft"), and at 160nm ahead, the beam-center is 16,000t below the aircraft.

Because the beam is about 3deg wide, the returns are, effectively, 3 x the distance x 100. At 80nm, a 3deg beam is 24,000ft wide.

By scanning "up", one can just catch the highest altitude at which water (not water vapour) is present, knowing that convective activity can go higher. Practically speaking again, a tilt of 3deg "UP" puts the bottom of the radar beam on the horizon. A zero-tilt means the radar is scanning 1.5deg above the horizon and 1.5deg below. One can easily work out the heights scanned at varying distances ahead of the aircraft from there.

Eighty nautical miles is okay for avoidance but 160nm is preferable as it provides a smaller detour angle and also permits one to see thunderstorms attenuated by the ones in front, much earlier.

By taking frequent "slices" up and down and using this knowledge, one can begin to build a slightly better picture of the convective activity ahead, that contains moisture.

All this said, every airline pilot knows that it is not good strategy to attempt to outclimb (overfly) a thunderstorm. We know that the height of convective activity can exceed the radar returns sometimes by a substantial margin and that when such activity is stopped in it's climb by the tropopause, if the thunderstorm is severe enough the resulting overhangs can contain hail thrown from the center of the building storm, so avoiding the overhangs by a wide margin is done.

We know that strong to very violent turbulence is indicated by curling red returns, (vortexes, essentially), as do hooks and very tight-grades (narrow bands of amber-against-red signals).

Every airline pilot knows that radar is used for weather avoidance, not weather penetration.

A moon-lit night provides excellent viewing of convective activity. Often one can, along with the distant tell-tale lightning, see the actual storms and, using radar, pick one's way between the build-ups. For the info of those that don't fly, it's done every day, thousands of times, with unremarkable success.

These techniques are not definitive. Within a reasonably narrow band defined by the radar installation itself, varying approaches to using and reading radar are used.

My only speculation at this point would be, whatever else the operating AF crew was doing as part of their SOPs for such weather, they were almost certainly looking out the windscreen while using the radar as described. As to the rest, I cannot fathom how, and why, anyone would speculate here or anywhere as to what happened, under the present state of knowledge.

PJ2

replying to Torquewrench's post regarding Carnivore, Mentor and the National Reconnaissance Office, if it's signals, if I am not mistaken, it is the province of the National Security Agency, not the CIA or NRO.

Sky King