Air France A330 Down

[Moon The Loon]

And so the Brazilian cover-up goes into high gear:

"It has been verified that the material did not belong to the plane," Brigadier Ramon Borges Cardoso told reporters in Recife about the material recovered Thursday. "It is a pallet of wood that is utilized for transport. It is used in planes, but on this flight to Paris, there was no wooden pallet."

He added that oil slicks seen on the ocean were not from the plane, either, and that the quantity of oil exceeded the amount the plane would have carried.

"No material from the airplane was picked up," he said.

The announcement left open the question of whether other debris that had not yet been plucked from the ocean might be from the plane."

http://www.cnn.com/2009/WORLD/americas/06/...rash/index.html

[Guest rattler]

On the subject of speed -- Airbus has evidently issued an notice.

http://www.reuters.com/article/worldNews/i...rldNews&sp=true

[RFL]

After that fiasco of an investigation on the Gol midair I'm not taking anything the Brazilians say at face value. 

Here is the link to the CENIPA report.

http://www.ntsb.gov/Aviation/Brazil-CENIPA...ish_version.pdf

I found it to be both extensive and professional.

You may be too young to know but it was not long ago that not following cardinal altitudes was a serious matter. In Canada, even while under full radar control in the SDA, full position reports were required and the words "wrong way" were required following the stated altitude.

[AIP]

DEFCON;

Re "evidence", here's a re-typed listing of the ACARS ECAM messages. They may not be in strict chronological order. WRN is "Warning", (red) and FLR is essentially "Caution", (amber). The ATA numbers can readily be seen.

Don

So if reading it correctly;

The A/P went off first, followed shortly after by the aircraft reverting to Alternate Law.

[boestar]

It also shows a Rudder Travel limiter fault. If rudder inputs of significant magnitude were made while trying to negotiate the storms this could have had a detrimental effect. If full rudder travel is allowed at speed this could definately cause controllability issues.

[Mitch Cronin]

I don't know from nuthin' but I'd be thinkin' that's just a slew of failure messages being sent while the sending could continue.... I'm wondering though if that "Nav ADR Disagree"in the midst of it all might be indicitive of an in flt break-up? ....wouldn't think power failures would cause that message...?

[J.O.]

I don't know from nuthin' but I'd be thinkin' that's just a slew of failure messages being sent while the sending could continue.... I'm wondering though if that "Nav ADR Disagree"in the midst of it all might be indicitive of an in flt break-up? ....wouldn't think power failures would cause that message...?

This is only speculation, as it's very early and there's still a ton to learn, but I'm thinking a radome burst as a possible "first event". It explains alot of what was happening in those early messages. Then again, I could be 100% wrong.

[DEFCON]

Thanks Don, the doc’s quite interesting.

I do appreciate the fact that the ac is down. My point, physical evidence supporting the theory of an in-flight breakup, or any other cause for the loss, is non-existent...yet?

Second from the bottom of the list is a "FLR" warning for a "LAV CONF". I'm not at all familiar with the Airbus data style, but could this entry mean the event originated in a "lav"?

[Don Hudson]

DEFCON;

No - the message is seen once in a while on normal flights - usually something to do with the vacuum system.

Mitch, if you or someone has access to an A330 Trouble Shooting Manual, these messages may be interpreted better. Also, I think the timing is a question - accurate to the nearest minute only, so we don't know if these are in exact sequence "as received" by ACARS, summarized at the end of each minute in no particular order or as the fault message occured upstream.

The NAV ADR DISAGREE is a "flag" for me as is "ATA341115" which has to do with "Probes - Pitot" but we dont' know specifically what. The TSM would help identify the ATA # and what the actual problem was - heat/data or..., and which pitot?

None of these messages enable us to conclude or even surmise anything but we can create educated scenarios until more is known.

[Evinrude]

More info,

Investigators confirm airspeed indication problem on Air France A330

French investigators have this morning confirmed that automatic messages transmitted by the Air France Airbus A330 lost four days ago show that the aircraft was experiencing conflicting airspeed information from its on-board sensors.

The brief statement from investigation agency BEA follows the issuance by Airbus of a telex to operators reminding them of immediate actions to be taken by crews in the event of unreliable airspeed indications.

It says: "Many more or less accurate or attempted explanations of the accident are currently circulating. The BEA reminds one that in such circumstances it is best to avoid any hasty interpretation or speculation based on fragmentary and unvalidated information."

At this stage of the investigation, it says, the only elements established are:

* The presence near the planned route of the aircraft over the Atlantic of signifcant convective cells characteristic of the equatorial regions

* From the automatic messages transmitted by the aircraft, the inconsistency of the different measured speeds.

The Airbus telex states: "The route of the aircraft was crossing a tropical multicell convective area at the time of the accident. Failure/maintenance messages have been transmitted automatically from the aircraft to the airline maintenance centre.

"The above mentioned messages indicate that there was an inconsistency between the different measured airspeeds. Therefore, and without prejudging the final outcome of the investigation, the data available leads Airbus to remind operators what are the applicable operational recommendations in case of unreliable airspeed indication."

It then provides operations manuals references for the entire Airbus-fielded fleet of aircraft.

A 2001 airworthiness directive previously mandated operators to ensure that aircraft flight manuals were updated with the procedures in the event of unreliable airspeed indications following a series of such events on the type. It indicated that severe icing of the pitot tubes or physical loss of the radome, which additionally requires an increase in power to counter the drag, were potential causes.

Sources in Brazil familiar with the investigative work say that icing is a key focus of investigation.

Source: Air Transport Intelligence news

***************

Air France jet's flight-control system under scrutiny

Automated messages before the crash point to a failure of the system that flies the plane most of the time, experts say. Weather looks like less of a factor.

A sophisticated flight-control system that relies on electronic instruments and computers came under growing scrutiny Thursday as investigators tried to unravel the mysterious crash of an Air France Airbus 330 into the Atlantic.

A series of messages sent automatically by the jet moments before it plunged into the ocean late Sunday with 228 passengers and crew members aboard has raised speculation that the crash might have involved a malfunction of the automated system that flies the plane most of the time.

One of the messages reported that one of the plane's navigational control units had failed and that, almost simultaneously, the autopilot system had disengaged.

The sequence of events forced the crew of Flight 447 to fly the jet manually, a difficult task on an Airbus traveling at high altitude near its maximum speed, aviation experts said. Any significant change in airspeed could have caused the plane to lose lift or stability, both potentially deadly conditions.

Meanwhile, new analysis of the weather in the vicinity at the time of the crash appears to cast doubt on earlier reports that the plane encountered severe thunderstorms, lightning and wind gusts. Though there were storms, they were almost certainly less intense than those sometimes encountered above the United States, and lightning was at least 150 miles away, said Greg Forbes, severe-weather expert for the Weather Channel.

Forbes said an examination of weather data for Sunday, including satellite images, indicated updrafts of perhaps 20 mph, far from the initial reports of 100 mph.

"I wouldn't expect it to be enough to break apart the plane," Forbes said.

Though experts generally agreed Thursday that weather alone did not explain the crash, USC aviation safety expert Michael Barr said the investigation was still wide open.

"You can never disregard any possibility until you can prove what happened," Barr said. "The key here is to determine what the crew could have done after the initial event. Or was there nothing they could have done and they were just along for the ride?"

Air France executives said the plane had sent out a series of messages indicating technical failures, confirming news reports in Brazil and data that U.S. aviation experts had already gained access to.

A series of serious electronic breakdowns occurred on the Airbus over a four-minute period before the jet plunged into the sea, said Robert Ditchey, an aeronautical engineer, pilot and former airline executive.

The sequence started with an autopilot failure and a loss of the air data inertial reference unit, a system of gyroscopes and electronics that provides information on speed, direction and position. That system has been involved in two previous incidents that caused Airbus jetliners to plunge out of control, though the pilots were able to recover.

The automated messages then indicate that a fault occurred in one of the computers for the major control surfaces on the rear of the plane. Such a failure would have compounded the problems, particularly if the pilots were flying through even moderate turbulence.

The last message indicates that multiple failures were occurring, including pressurization of the cabin. Such a message would have reflected either a loss of the plane's pressurization equipment or a breach of the fuselage, resulting in rapid decompression.

All of these issues would have made the plane difficult to control.

When cruising at high altitude, a plane must fly within a fairly small window of speed, said Robert Breiling, an aviation safety expert in Florida. If speed drops even slightly, the plane can lose lift. If the speed is too high, it causes instability over the control surfaces.

"Flying a big jetliner at high altitude without autopilot, you have your hands full," Breiling said.

Ditchey said the Airbus software would have left the crew with a very small margin of error, where even minor buffeting could have boosted the risk of losing control.

"As they got into a degraded regime, they probably got into a bigger and bigger pickle," Ditchey said.

http://www.latimes.com/news/nationworld/wo...0,6741218.story

****************

[Evinrude]

One more important info

Memo: Air France replacing flight instruments

PARIS (AP) — An Air France memo to its pilots Friday about the crash of Flight 447 said the airline is replacing instruments that help measure airspeed on all its medium- and long-haul Airbus jets.

Investigators have focused on incorrect speed readings as one potential factor in the crash.

With Brazil and France disagreeing about whether pieces of the jet have even been found in the Atlantic, investigators are using the last messages sent by the plane to determine the cause and try to avoid future disasters.

Air France declined to comment on the memo obtained by The Associated Press, saying it was for pilots only.

[handyman]

Note to file...flying into CB's is bad! Flying into many CB's is VERY BAD!

[Alt*]

Just received this link in my company email, interesting data

http://www.weathergraphics.com/tim/af447/

[Seeker]

Just received this link in my company email, interesting data

http://www.weathergraphics.com/tim/af447/

Just received it? That link was posted (by me) on page 1 of this discussion four days ago.

[Guest rattler]

One more important info

Memo: Air France replacing flight instruments

PARIS (AP) — An Air France memo to its pilots Friday about the crash of Flight 447 said the airline is replacing instruments that help measure airspeed on all its medium- and long-haul Airbus jets.

Investigators have focused on incorrect speed readings as one potential factor in the crash.

With Brazil and France disagreeing about whether pieces of the jet have even been found in the Atlantic, investigators are using the last messages sent by the plane to determine the cause and try to avoid future disasters.

Air France declined to comment on the memo obtained by The Associated Press, saying it was for pilots only.

Looks like they, if this article is accurate, did not take the earlier action as recommended by Airbus. I wonder how many other airlines didn't either?

Air France did not replace instruments, says official

Emma Vandore

ASSOCIATED PRESS

PARIS – The agency investigating the crash of Flight 447 says Air France had not replaced instruments that measure air speed on the plane, which the manufacturer had recommended.

Agency head Paul-Louis Arslanian says some problems had been detected with the instruments on the Airbus A330, the model that disappeared over the Atlantic Ocean on May 31.

Arslanian says Airbus had recommended that airlines replace the instruments on the A330. The head of the crash investigation says Air France had not changed the instruments known as Pitot tubes on the plane that crashed.

Arslanian warned on Saturday against jumping to conclusions.

He says planes can be flown safely "with damaged systems."

An Air France memo Friday said it is replacing Pitot tubes on all medium- and long-haul Airbus jets.

 

[Moon The Loon]

One very common element of European and middle east flying I observed over the last 8 years was the propensity to fly to high, sometimes 6,000' above optimum altitude. Such practice further reduces lo/hi margins with the misguided perception that fuel is being saved. In fact, fuel is wasted getting to these heights and fuel is wasted staying there.

When penetrating lines of weather such as is being discussed here, it is natural to want to get as high as possible to give a better chance to "navigate the tops".

It will be interesting to see just where they were with respect to optimum altitude once the dust settles.

[J.O.]

FL350 is a pretty low optimum altitude for the A330. From what I know of their payload, FL350 was well within the normal envelope for the airplane that day.

[Guest rattler]

Confirmation that remains and debris have now been found.

http://news.bbc.co.uk/2/hi/americas/8087303.stm

[Don Hudson]

Link to the relevant AD referenced above. Note that it applies to "300" series A330's however, and I believe the A330 that was lost was a 200-series aircraft.

I'm not familiar with the way these things work so am not sure whether it can be said that AF complied or not. We have to be really careful with so little information.

J.O. - agree that 350 is a ways from "coffin corner", (a term which is no longer useful or relevant with the kind of planning and information we have today). The AOM has both All Engine MAX altitudes and Buffet Boundary charts and by both charts, assuming they were about 210k T, even with ISA +15 they had signficant "room".

[Moon The Loon]

Thanks Jeff/Don: I was sure 350 was a good FL for a heavy 330. One thing ruled out. It's still a little disconcerting listening to all the scuttlebutt about the symptoms of the main event, whatever that main event was. It is still to early to know what the first link in the series of events was.

[handyman]

J.O. - agree that 350 is a ways from "coffin corner", (a term which is no longer useful or relevant with the kind of planning and information we have today).

Actually, it's no longer relevant due to aircraft design changes which don't create a significant "corner" as they once did in some models.

[Evinrude]

Actually, it's no longer relevant due to aircraft design changes which don't create a significant "corner" as they once did in some models.

Actually, it's no longer relevant due to aircraft design changes which don't create a significant "corner" as they once did in some models.

I don't understand your affirmation. In my book an A330-200 at 350 may well have been at the max altitude for the weight they were at. If you cross a line of thunderstorms at that max altitude you will be hurting.

I prefer to descend. My comment is based on a night flight in non radar environment where it would take you 10 minutes to get an altitude change request acknowledged.

I was a while back a captain on a flight from India to Australia, upon my return to the cockpit after a rest, the relief captain was navigating at night through TS and was leaving 350 for 370 to be on top. Standing up, in the cockpit behind him I told him that it was not a good idea and requested to change the clearance to return to 350. As he was starting to tell me it will be ok, we hit a wall at 365. The aircraft had no choice but to go down to fly again.

370 was the max altitude for our weight. We recovered at 345 from our controlled (voice activated request from the jumpseat) descent from 365 to 350.

For me in an Airbus, unless I am navigating day time around cells, I will never climb to max altitude. I will maintain max minus 1500 as a buffer.

My opinion only, what do you guys do?

[Moon The Loon]

370 was the max altitude for our weight. We recovered at 345 from our controlled (voice activated request from the jumpseat) descent from 365 to 350.

For me in an Airbus, unless I am navigating day time around cells, I will never climb to max altitude. I will maintain max minus 1500 as a buffer.

My opinion only, what do you guys do?

That kinda illustrates my point, Evinrude. I have no comment on what might be optimum vs max for weight - I take J.O.'s comment as factual, and I have some familiarity (via a former company) that 350 seemed reasonably close to optimum for the -200. But again, no comment on that particular part of the discussion.

Max altitude for weight? Never!!! And that was my point - you have no options should you encounter a moderate/severe turbulence event - and that can happen anytime, especially in Europe from wake turbulence.

Our job is to maintain viable options. Flight at maximum altitude for weight is not one of 'em in my books!

[Canus Chinookus]

Confirmation that remains and debris have now been found.

http://news.bbc.co.uk/2/hi/americas/8087303.stm

looking at the track they're marking on the map, it looks like they were flying around the weather, not through it.

[handyman]

I don't understand your affirmation. In my book an A330-200 at 350 may well have been at the max altitude for the weight they were at. If you cross a line of thunderstorms at that max altitude you will be hurting.

A "coffin corner" was a term for aircraft types operating at such an altitude with a wing that caused a stall should the aircraft slow and an overspeed if it accelerated. These days people use the term when the window gets relatively small but it's not the corner it used to be!