FolhaOnline – LeMonde – ALT LAW Chatter – FAB Nota 39


UPDATE II: Not to be misunderstood:  BEA Press Release, June 23, 2009 (Emphasis mine)

No signals transmitted by the flight recorders’ locator beacons have been validated up to now. In the context of the sea searches that are under way, work is undertaken on a regular basis that is aimed at eliminating any doubts related to any sounds that may be heard, and any findings will be made public.

UPDATE: As one would expect the French Government denies the LeMonde Article…

(AP) The official, an aide to France’s minister in charge of transport, Jean-Louis-Borloo, denied a report in the French newspaper Le Monde that French ships had picked up a signal from the black boxes.

French military ships searching in the area where the plane crashed have “heard sounds” but “the black boxes have not been detected,” she said. The aide spoke on condition of anonymity because she was not authorized to be publicly named.


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French navy finds sign of the black box of Airbus, says newspaper (English Translated)(Emphasis mine)

23/06/2009 – 04h41 da Folha Online Atualizado às 07h31.

The French Navy located in this Tuesday, a weak signal from the black box of the Air France Airbus who disappeared on May 31 in the Atlantic Ocean, the report shows the French newspaper Le Monde. ” Air France does not confirm the news and the military did not comment on the matter.

The newspaper reported that Argonaut was mini-submarino to the place to check the sound object in the region where the plane crashed – the approximately 850 km from the archipelago of Fernando de Noronha (PE). The search for black-boxes are made with the greatest urgency possible, since the batteries of the flag of the equipment lasts 30 days.

The report does not reveal the source of the information, nor the exact location of the area where the equipment was located. “The searches have become complicated [because of the topography of the ocean],” says “Le Monde”. According to the newspaper, the black-boxes “still have the autonomy to approximately eight days.” The beacons that emit the sound signals for the location are the size of a large stack and are connected to the black box.

The French Commission of Investigation (BEA), French government agency responsible for investigation of the accident, said that equipment, which store data crucial to explain the accident, have not been “located” with precision. The body said that this is not the first time that researchers detect underwater noises, and they are all investigated. At the beginning of the investigation, the director of BEA, Paul-Louis Arslanian, came to ask for caution in searches, even because there was the assumption that the sensors could be separated from the equipment after the fall…

For BEA, the black box is considered essential to clarify the causes of the accident, which occurred in Rio-Paris route. Investigations continue but no conclusive explanation of what may have knocked the plane. It is known that the plane had an electrical failure and depressurization of the cabin, because alerts were sent during the type of flight.

A failure in external sensors that measure the speed of the aircraft, the Pitot, was identified as a possible cause of the accident. The president of EADS (European Society of Aeronautic and Defense, which controls Airbus), Louis Gallois, “this type of accident , there is [only] questions. ” “It is the convergence of different causes, creating an accident. It is essential that everyone knows what happened.”

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LEMONDE.FR | 23.06.09 | 06h59  •  Mis à jour le 23.06.09 | 11h50

Search flight Rio-Paris: questions about the signals received (English Translated)(Emphasis mine)

The investigation into the causes of the crash of the Air France A330 operating the flight Rio-Paris, who disappeared on June 1st in the Atlantic off the coast of Brazil, will it grow in the coming days? Perhaps, if the black boxes from the aircraft – the flight recorders – are “physically” located and, more importantly, it is possible to return to the surface. In any case, the “hope” that has sprouted, Tuesday 23 June, after the submarine Nautile pocket of Ifremer has made a dive after having received a signal. Story of what we know and questions that remain.

According to information collected by Le Monde, the buildings of the French Navy who are trying to find the remains of the A330 of Air France have received a very low faint signal.

It was considered that this signal could come from the black boxes from the aircraft. This led, Monday 22 June, the submarine Nautilus to make a dive. The aim is to try to physically “get their hands on these black boxes and power them up: the black boxes are located in the tail of the aircraft, it is not certain that the submarine can retrive.

Asked about the search operation, a spokesman for the Bureau of Investigation and Analysis (BEA) – the french official body responsible for the technical investigation – said that these black boxes have not yet been precisely ” localized. An official of the BEA is however expected in the day.

“We are still in research phase,” said on Europe 1, Philippe Guillemet, the commander of the “Why Not?” Vessel Ifremer on this area of research. “The acoustic waves, it receives, but nothing is confirmed, unfortunately,” continued the captain, who, when asked “you have not spotted any of the black boxes?” replied: “Absolutely.”

The search for these black boxes is anything but simple. Firstly, the tags contained in the flight recorders emit signals that are “be received” in a radius of 2 km. Secondly, because the place where the Air France plane crashed is characterized by a relief submarine very tormented the funds at around 5 000 m deep. (Read the article “Rio-Paris Flight: gear submarine mobilized to retrieve the black boxes”). Finally, at these depths, the visibility is zero, the seabed is plunged into darkness.

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ADR DISAGREE CHATTER

Comment/Question:  As I understand it, the various ‘protections’ are reduced under ‘alternate law’ – but some remain, including ‘angle of attack’ protection? Basically, that if the nose gets too high at low speed, the protection pushes it down for you? Please set me straight if either of those assumptions are wrong.

There are 3 modes of FBW degradation… plus Abnormal Law (for upset attitude).

If you degrade from Normal law, you have ALTN 1, ALTN 2, then Direct law…

Anything below that, it’s Mechanical Control… (for temporary total loss of electrics).

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Notes:

* = Only in case the AOA, of the remaining ADRs, disagrees with the AOA (as computed by PRIMs)

(1) = Protection is totally lost, in in case of VS1g computation (loss of weight, or slat/flap position).

(2) = Protection is lost, in case of dual ADR failure (or ADR DISAGREE)

(3) = Protection is lost, in case of triple ADR failure (or ADR DISAGREE)

(4) = Bank angle limitation remains effective in ALT 1, which uses roll normal. However since ALT 1 is generally an unprotected law, all protection marks on the PFD are in amber for simplicity.

(5) = When both elevators have failed, only pitch mechanical backup is available, by using the manual pitch trim control (THS). “MAN PITCH TRIM ONLY” is displayed in red on the PFDs.

Pitch ALT = Same as normal, refer to remaining protection boxes below it.

Lat NORM = As per normal law

Roll DIR = Roll as per Direct Law, no Bank Angle protection. Max roll rate approx 20 – 25deg/sec depending on speed & config. Spoilers 2, 3, 6 inhibited, except in case of of additional failures affecting lateral control.

Yaw ALT = The dutch roll damping function is available, and damper authority is limited to +/- 4 deg rudder (CONF 0) and +/- 15deg (in other configuration). Turn coordination is also provided, except in CONF 0.

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(Yaw Alt = still no need to press rudder for turns… rudder trim still avail).

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They got an ADR disagree ECAM message, by that time, they’re in ALT 2.

Comment/Question: So the question is, even if the pitots/ASIs are under-reporting the airspeed, do the ‘protections’ go on getting their airspeed information from them? And if so, could that explain all those ‘stall warnings’ that have been reported, even though the aeroplanes in question were not stalling?

The stall warnings can come from either of these:

1. Indicated airspeed below Vsw (stall warning speed)… since the Vsw will be indicated on the speedtape…

2. The AoA computed by the PRIMs (Attitude vs vertical drift at current gross weight = a calculated IAS < Vsw).

Am not sure on the detailed mechanics of stall warnings at unreliable airspeed. As far as I know, there is no difference between stall warning #1 and #2 above. The reason being is, you can have ADR problems or IRU problems… I’ll have another look in the books…

Hence the QRH says “Respect Stall Warnings” despite ECAM saying “Risk of Undue Stall Warning”…

In the case of Air Caraibes, they were at manual thrust when the mess happened, so they already had the “thrust/pitch” speed relationship and made the judgment call of… “it’s a false stall warning”… no matter what the speed tape says…

In the case of Air France, they were at autothrust when the [event] happened… one would be at risk of not having the thrust/pitch speed relationship in one’s head beforehand… they would be in the same “blank” regarding to thrust/pitch relationship based on the risk you mentioned earlier, “could the speed tape indicate a speed slower than their speed” (although you directed at the rudder travel limiter, you actually were on to this…)

The AoA vane compared to AoA computer by PRIM compared to speed tape could have resulted in the system determining there was an error… that’s what the computers knew… what did it then do? Basically “Guys, something is wrong with the speed I’m getting, sort it out and fly the plane until you know which one is wrong”. But what the pilots saw could have been a progressively slowing IAS on the speed tape…

Air Caraibes case also had wild and rapid fluctuations of the speed tape, which given they were already on the manual thrust, they could just say to the the PFD… “U’re bluffing! sod the stall warning!”.

The crew on AF447 didn’t have that ironic luxury…

“STALL??? Is it real stall? or fake stall? What does the QRH say?”

“Technical recommendations:

– Respect stall warning, and disregard the “RISK OF UNDUE STALL WARNING” STATUS message if Displayed on ECAM.”

What would you do? Follow or not follow?


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Resgate de Corpos do navio da Marinha /

FORÇA AÉREA BRASILEIRA

22/06/2009 – 17h49 Nota 39 – 22.06.09

INFORMAÇÕES SOBRE AS BUSCAS DO VOO 447 DA AIR FRANCE

The Brazilian Navy and Air Force Command report that, in this Monday, March 22, remain possible sighted wreckage about 1100 km north of Fernando de Noronha. No bodies were sighted. The landing ship dock-Rio de Janeiro was informed of the location of these materials.

Reached the port of Recife, to 11.15, the tanker Admiral Motta Gastão bringing the latest body found, and remains, and small amount of wreckage and luggage. The body and the remains were delivered to representatives of the Federal Police and the Legal Medical Institute of Pernambuco (IML). The material collected will be available to the Bureau d’Investigations et D’Analysis of I’Aviation Pour la Securite Civile (BEA).

Completed three weeks of operation, the aircraft flew about 1,350 hours and was conducted visual searches in 320,000 square kilometers, amounting to more than twice the size of the state of Ceará.

There was no change in number of vessels involved in search, but the effective military Navy rose to 885, increasing to 1,100 the number involved in the operation. The conduct adopted for the work remains unchanged in relation to information provided previously.

CENTRO DE COMUNICAÇÃO SOCIAL DA MARINHA
CENTRO DE COMUNICAÇÃO SOCIAL DA AERONÁUTICA

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