Air France 447 - Update Recommendations

BEA New Safety Recommendations

Published: June 5, 2012

Publicado em 05 JUN 2012

BEA Novas Recomendações de Segurança

Analysis of the flight based on the readout of the flight recorders has led to the issuing of the new safety recommendations.

• Three safety recommendations relating to operations.

Análise do voo baseado na leitura dos gravadores de voo conduziu à emissão de novas recomendações de segurança.

• Três recomendações relativas às operações.

Training for manual airplane handling

The first recommendations that the regulatory authorities re-examine the content of training and check programs and in particular make mandatory the creation of regular specific exercises aimed at manual airplane handling.

Approach to and recovery from stall, including at high altitude.

Treinamento para manuseio MANUAL [sem Piloto automático] da aeronave.

As primeiras recomendações que as autoridades reguladoras reexaminem o conteúdo de treinamento e programas de chck e em particular faça mandatório a criação de exercícios específicos regulares mirado no manuseio manual do avião.

Aproximação e recuperação de perda de sustentação (STALL), incluisive em alta altitude.

 

Relief Captain

The following two recommend that the regulatory authorities define additional criteria of access to the role of relief Captain in order to ensure better task-sharing in case of relief crews.

• One recommendation relate to airplane certification

Revezamento de Comandante

As duas seguintes recomendam que as autoridades reguladoras definam adicionalmente critérios de acesso ao papel de revezamento do Comandante para assegurar melhor compartilhamento de tarefa no caso de revezamento de tripulantes.

Angle of Attack measurement

This recommends that the regulatory authorities evaluate the relevance of requireing the presence of an angle of attack indicator directly accessible to pilots on board airplanes.

Medição do Ângulo de Ataque [AoA]

Esta recomenda que as autoridades reguladoras avaliem a relevância de requererem a presença de um indicador de ângulo de ataque diretamente acessível aos pilotos a bordo dos aviões.

 

Cruise. Range is a function of both the aerodynamics of the airplane and the fuel-flow characteristics of the engines. Aerodynamically, the minimum drag point occurs at the point where the L/D is a maximum. But this value depends on both AOA and Mach number, so the optimal AOA will vary as Mach number is changed.

Cruzeiro. Alcance é uma função de ambas características, aerodinâmica do avião e fluxo de combustível dos motores.  Aerodinamicamente, o ponto de arrasto mínimo ocorre no ponto onde o L/D [Sustentação/Arrasto] é um mínimo. Mas este valor depende de ambos, AoA e número Mach,  assim o AoA ideal variará quando o número Mach for mudado.

The fuel-flow characteristics of the engines are not affected by AOA, but they do depend on the thrust required (drag), Mach number, and temperature.

Combining the wing and engine characteristics yields the fuel mileage of the airplane, so fuel mileage is a strong function of Mach number. Figure below shows the fuel mileage of a 757-200 at an altitude of 35,000 ft as a function of gross weight and Mach number.

As características de fluxo de combustível dos motores não são afetadas pelo AoA, mas elas dependen da potência exigida (arrasto), número Mach e temperatura.

Combinando as características da asa e motor produz a milhagem de combustível do avião, assim a milhagem de combustível é uma função efetiva do número mach.  A Figura abaixo mostra a milagem de combustível de um 757-200 numa altitude de 35.000 pés como uma de função de peso bruto e número Mach.

It can be seen that the optimal long-range cruise Mach number does not vary significantly as gross weight (hence, lift and AOA) changes. Superimposed on this chart are two lines of constant AOA. It is apparent that flying a constant AOA will not yield optimal performance. If a flight crew tried to fly a target AOA and there was an error of as little as 0.5 deg, the penalty in fuel mileage could be 3 percent or more.

Pode ser visto que o número Mach ideal de cruzeriro de longo alcance não varia significantemente quando o peso bruto (portanto, sustentação e AoA) muda.  Sobrepostas neste gráfico estão duas linhas de AoA Constante.  É óbvio que voando uma AoA constante não renderá uma performance mais favorável. Se uma tripulação de voo tentasse voas umAoA alvo e houvesse um erro tão pequeno quanto 0.5 graus, a penalidade na milhagem de combustível poderia ser 3 por cento ou mais.

Wind is a more fundamental consideration. For best fuel mileage in a headwind, the airplane should be flown faster than the speed for best range in still air; in a tailwind, it should be flown more slowly. Most modern Boeing airplanes have a flight management computer (FMC) that accounts for airplane, engine, and wind characteristics and can compute the optimal speed to be flown.

Vento é uma consideração fundamental.  Para a melhor milhagem de combustível com vento de proa, o avião deve ser voado mais rápido do que a velocidade para o melhor alcance em ar calmo; com vento de cauda, ele deve ser voado mais lentamente. Muitos aviões Boeings modernos têm um computador de gerenciamento de voo ( FMC) que calcula características para o avião, motor e vento e, pode calcular a velocidade mais favorável para ser voada.

Four recommendations on flight recorders

Images recorders

One recommends that the regulatory authorities riquere that aircraft undertaking public transport flights with passengers be equipped with an image recorder that makes it possible to observe the whole of the instrument panel. Another recommends defining strict rules raleting to the use of such recordings.

Quatro recomendações de gravadores de voo

Gravadores de imagens

Uma recomenda que as autoridades reguladoras requeiram que aeronave empreendendo voos de transporte púclico  com passageiros sejam equipadas com um gravador de imagem que faça isso possivel para observar o painel inteiro de instrumento. Uma outra recomenda definir regras austeras [estritamente confidenciais] relativas ao uso de tais gravações.

Flight parameters recordings

There are two recommendations on the recording additional parameters

• There are two recommendations on the transmission of flight data.

Registros de parâmetros de Voo

• Há duas recomendações na transmissão de dados de voo.

One recommends that the regulatory authorities make mandatory the triggering of data transmission to facilitate localization when an emergency situation is detected on board. The other recommends studying the possibility of making mandatory the activation of the Emergency Locator Transmitter (ELT) when an emergency situation is detected on board.

Uma recomenda que as autoridades reguladoras torne mandatória o desencadeamento [disparo automático] da transmissão de dados para facilitar a localização quando uma situação de emergência for detectada a bordo. A outra recomenda estudar a possibiidade de tornar mandatória a ativação do ELT - Transmissor Localizador de Emergência, quando uma situação de emergência for detectado a bordo.

Source BEA

Evidence That Pilots Are Failing - FAA Says - Maybe to Colgan and AF447

STALL recovery review posted here on SEP 2011
http://aviationtroubleshooting.blogspot.com/search?updated-max=2011-10-12T06:04:00-03:00&max-results=6



ENGLISH   PORTUGUÊS


DRAFT
Advisory Circular
Stall and Stick Pusher Training
Initiated by: AFS-200
AC No: 120-STALL

An aircraft stall warning system includes an angle of attack sensor which provides a signal to an angle of attack processor which provides an angle of attack signal to a display. An air pressure sensor provides an air turbulence intensity ratio signal to an aerodynamic performance processor which provides an aerodynamic performance signal to the display. The display therefore simultaneously displays both theoretical stall margin and actual stall margin to thereby provide a pilot with wing contamination information.

Um sistema de alarma de stall [perda de sustentação] de aeronave inclui um sensosr de ângulo de ataque {AoA}, o qual fornece sinal para um processador de ângulo de ataque, o qual fornece sinal do ângulo de ataque para um mostrador. Um sensor de pressão do ar fornece um sinal da taxa de intensidade do ar turbulento para um processador de performance aerodinâmica, o qual forcenece um sinal de performance aerodinâmica para o mostrador. O mostrador todavia apresenta simultaneamente ambas margem teórica de stall e margem real de stall para em consequência prover um piloto com informação de contaminação de asa.

The history of accidents resulting from loss of control (LOC) following a stall indicates the need for providing realistic scenarios from which pilots may be taught to respond to inadvertent stall conditions.

A história de acidentes resultantes de perda de controle (LOC) seguindo uma perda de sustentação indica a necessidade de fornecer cenários realísticos, nos quais pilotos podem ser ensinados a responder às condições inadvertidas de stall.

(1)  With one or two remarkable exceptions, most accidents have occurred following an approach-to-stall while flying on autopilot. Nonetheless, many air carriers and operators have traditionally trained their pilots to enter an approach-to-stall condition without the aid of an autopilot. The most challenging difference between an approach-to- stall event with the autopilot engaged and one that was flown by the pilot, is the abrupt pitch and trim change commonly associated when the autopilot unexpectedly disconnects. This dramatic pitch and trim change typically represents an unexpected physical challenge to the pilot when trying to reduce angle of attack (AOA).

(1) Com uma ou duas exceções notáveis, muitos acidentes têm ocorrido seguindo uma aproximação-de-stal, enquanto voando no piloto automático. todavia, muita empresas aéreas e operadores têm tradicionalmente trinado seus pilotos para entrar numa condição de aproximação-de-stall sem a ajuda de um piloto automático. A maior diferença desafiante entre um evento de aproximação-de-stall com o piloto automático engajado e uma que foi voada pelo piloto, é o abrupto pitch {ângulo} e mudança de trim {compensador} comumente associados quando o piloto automático inesperadamente disconecta. Esta mudança dramática de 'pitch' e 'trim' tipicamente representa um desafio físico inesperado para o piloto quando tentando reduzir o ângulo de ataque (AoA).

(2) The situation may be exacerbated in some aircraft by a pitch up moment resulting from the pilot increasing the power in response to the approach-to-stall warning. In addition to the dynamic pitch changes experienced, the noises associated with stick shakers and autopilot disconnect alarms add to the confusion in the cockpit. These noises present a real distraction as well as an alert to the pilots and are not present unless the stall scenario is accomplished with the aircraft’s autoflight systems engaged. Today’s FFSs enable pilots to experience these effects without the risks associated with actual aircraft flights.

(2) A situação pode ser exacerbada em muitas aeronaves com um momento de elevação do nariz da aeronave resultante do piloto aumentar a potência em resposta ao aviso de aproximação-de-stall. Em acréscimo às mudanças dinâmicas de 'pitch'experimentadas, os ruídos associados ao Stick Shakers e alarmas de desconexão do piloto automático adicionados à confusão na cockpit. Estes ruídos apresentam uma distração real tanto quanto um alerta para os pilotos e não estão presentes, a menos que o cenário de stall seja realizado com o sistema de piloto automático da aeronave engajado. Os Simuladores de Voo Completos de hoje capacitam pilotos a experimentar estes efeitos sem os riscos associados em voos reais de aeronaves.

b. Emphasis on AOA.

It must be emphasized that the only way to recover from a stall or an approach-to-stall is to reduce AOA, and such recovery will almost always result in some loss of altitude. In fact, in a very high altitude event, the recovery from an approach-to-stall may require thousands of feet of descent.

b. Ênfase no AoA.

Deve ser enfatizado que o único jeito de se recuperar de um stall ou uma aproximação-de-stall é reduzir o AoA, e tal recuperação quase sempre resulta numa perda de altitude. De fato, num evento em altitude muito elevada, a recuperação de uma aproximação-de-stal pode exigir milhares de pés de descida.

c. High Altitude Stall.

Jet aircraft and high-performance turboprops have very high cruising altitudes and little residual thrust is available. Pilots should be trained to make measured and proportional control inputs that acknowledge the extra sensitivity (increased pitch rates) of flight controls in this regime, and they must demonstrate the ability to sacrifice altitude to recover. Applicable sections of the Airplane Upset Recovery Training Aid on high altitude stalls should be used in air carrier training programs.

c. Stall em Alta altitude.

Aeronave à jato e turbo-hélices de alta performance têm altas altitudes de cruzeiro e pouca potência residual disponível. Pilotos devem ser treinados a dar entrada de controle proporcional e sob medida que reconheça a sensibilidade extra (taxa de pitch aumentada) de controles de voo neste regime, e eles devem demonstarar a habilidade de sacrificar altitude para recuperar. Seções aplicáveis de Ajuda do Treinamento de Recuperação de Aeronave Descontrolada em stalls em alta altitude deve ser usadas nos programas de treinamento de empresas aéreas comerciais.

d. Automated Flight.

The vast majority of incidents following approach-to-stall events in aircraft occur during automated flight. Approach-to-stall maneuvers should be practiced with autopilot on when available. When autothrottles are installed, the instructor/examiner may wish to disable them—with or without the pilots’ knowledge. Scenario-based stall events should include both AP and hand-flown scenarios.

d. Voo automatizado.

A grande mairia de incidentes seguindo eventos de aproximação-de-stall em aeronave ocorre durante voo automatizado. Manobras de aproximação-de-stal devem ser praticadas com piloto automático ligado [engajado] quando disponível. Quando Autothrottles {sistema automático de aceleração/desaceleração de potência} estão instalados , o instrutor/examinador pode desejar desabilitá-los - com ou sem o conhecimento dos pilotos. Eventos de stall em baseado em cenário devem incluir ambos  Piloto Automático e cenários de voo manual.

e. Crew Concept.

Since real world stall events normally surprise (or startle) the flightcrew, it is recommended that any line-oriented stall training event be introduced in such a way as to surprise all crewmembers if practical. If an instructor must use the pilot monitoring (PM) to help provide a surprise stall event to the pilot flying (PF), as soon as an approach-to-stall indication exists, the PM should resume proper crew responsibilities in the recovery.

e. Conceito de Tripulação.

Uma vez que eventos de stall no mundo real normalmente surpreende (ou assustam) a tripulação de voo, é recomendado que qualquerlinha orientada de evento de treinamento de stall seja introduzida de um tal modo que surpreenda todos membros da tripulação se for prático. Se um instrutor deve usar o Pilot Monitoring {PM} para ajudar fornecer um evento de surpresa de stall para o Pilot Flying {PF}, tão logo quanto exista indicação de aproximação-de-stall, o PM deve assumir as responsabilidades apropriadas de tripulante na recuperação.

f. Original Equipment Manufacturer (OEM) Procedures.

The primary authority on approach-to-stall recovery is the aircraft manufacturer.
Nothing in this AC should be construed as overriding OEM procedures.

f. Procedimentos Originais do Fabricante do Equipamento.

A autoridade primária na recuperação de aproximação-de-stal é o fabricante da aeronave. Nada nesta Circular deve ser imterpretado como neutralizando procedimentos OEM.

g. Energy Management.

Most stalls occur when sufficient altitude is available for the crew to recover. Pilots are to be trained and evaluated on their timely response and effective use of available energy (i.e., altitude and speed) when presented with a stall scenario. At no time should minimum altitude loss be a criterion for successful demonstration of an approach-to-stall or full stall recovery. Rather than instinctively using maximum power, the recovery should emphasize energy management and power application, as required depending on the situation. If the approach-to-stall occurs prior to the approach phase, the recovery may simply require a pitch over and an increase in power. If the approach-to-stall occurs much lower and ground contact becomes a factor, then a larger thrust increase may be required, which might result in an unstabilized approach at low altitude and result in a go-around. The successful recovery from a stall scenario requires the evaluator to consider the pilot’s response to the situation with which they are confronted.

g. Gerenciamento de Energia.

Muitas perdas de sustentação ocorrem quando altitude suficiente está disponível para a tripulação recuperar. Pilotos estão para ser treinados e avaliados nas suas respostas oportunamente e efetivo uso de energia disponível (exemplo, altitude e velocidade) quando apresentada com um cenário de stall. Em nenhum momento deve a perda minima de altitude ser um critério para demonstração bem sucedida de uma aproximação-de-stall ou recuperação completa de stall. Mesmo que instintivamente usar potência máxima, a recuperação deve emfatizar gerenciamento de energia e aplicação de potência, como requerida dependendo da situação. Se a aproximação-de-stal ocorre antes da fase de aproximação, a recuperação pode simpesmente exigir um 'pitch'a mais e um aumento de potência. Se a aproximação-de-stall ocorre muito baixa e contato com o solo torna-se um fator [de risco], então um maior aumento de potência pode ser exigido, o qual pode resultar numa aproximação desestabilizada em baixa altitude e resultar numa arremetida. A recuberação bem sucedida de um cenário de stall exige do avaliador considerar a resposta do piloto à situação com a qual eles são cofrontados.

h. Simulator Capabilities.

Instructors and evaluators must understand the fidelity limitations of the particular simulator.

h. Capacidade do Simulador.

Instrutores e avaliadores devem entender as limitaçoes de fidelidade do simulador em particular.

i. Stall Entry.

The tradition of having pilots memorize routines to enter an approach-to-stall is of little or no value for training for the actual inadvertent event in an aircraft.
This AC recommends that the responsibility for the setup be shifted from the trainee to the trainer/evaluator. Therefore, the instructor/evaluator needs to demonstrate creativity in presenting the stall event.

i. Entrada em Stall.

A tradição de ter os pilotos que memorizar rotinas para entrar numa aproximação-de-stall é de pouco ou nenhum valor para treinamento para o evento inadvertido real numa aeronave.

Esta Circular recomenda que a responsabilidade para o ajuste seja deslocada do [piloto] em treinamento para o treinador/avaliador. Embora, o instrutor/avaliador necessite demonstar criatividade em apresentar o evento de stall.

Training organizations should adjust their stall evaluation criteria as appropriate and train their evaluators in these changes. The primary goal of checking should be to evaluate a pilot’s immediate response to a stall warning indication and their timely, correct accomplishment of the

AFM-approved stall recovery procedure.

Organizações de treinamento devem ajustar seus critérios de avaliação de stall como apropriar e trainar seus avaliadores nestas mudanças. A meta principal de verificação deve ser avaliar a resposta imediata do piloto à indicação de aviso de stall e sua oportuna, realização correta do procedimento de recuperação de stall aprovado no Manual de Voo da Aeronave.

Evaluation Perimeters.

The examiner (not the applicant) is responsible for establishing the flight conditions associated with the approach-to-stall configuration being evaluated. While the applicant may fly the entry profile, they are not being evaluated on the entry. The satisfactory completion of the event is based on the pilot’s immediate response to a stall warning indication and if they accomplished the approved stall recovery procedure.

Perímetros de Avaliação.

O examinador (não o candidato) é responsável pelo estabelecimento das condições de voo associadas com a configuração de aproximação-do-stall sendo avaliado. Enquanto o candidato puder voar o perfil de entrada, eles [perímetros] não estão sendo avaliados na entrada. A conclusão satisfatória do evento é baseada na resposta imediata do piloto para a indicação de aviso de stall e se eles completaram o procedimento aprovado de recuperação do stall.

Evaluation Criteria.

Evaluation criteria for a recovery from an approach-to-stall must not mandate a predetermined or minimum loss of altitude. Proper evaluation criteria must consider the variables that are present at the time of the stall warning and their effect on the recovery altitude. The pilot should recover to the maneuvering speed appropriate for the aircraft configuration without exceeding the aircrafts limitations or losing excessive altitude consistent with the aircraft performance capabilities. It is expected that some loss of altitude will occur during the recovery. The pilot should, however, give due consideration to clearance from terrain during the recovery. Failure to do so would be considered unsatisfactory performance.

Critérios de Avaliação.

O critérios de avaliação para uma recuperação de uma aproximaçã-de-stall não deve ordenar uma predeterminada ou perda mínima de altitude. O critério de avaliação apropriado deve considerar as variáveis que estão presentes na hora do aviso de stall e seus efeitos na altitude de recuperação. O piloto deve recuperar a velocidade apropriada da manobra para a configuração da aeronave sem exceder as limitações da aeronave ou perder excessiva constante altitude com a capacidade de performance da aeronave. É esperado que alguma perda de altitude ocorrerá durante a recuperação. O piloto deve,  todavia, ter consideração com a dosobstrução do terreno durante a recuperação. Falha para fazer assim seria considerada performance insatisfatória.

Realistic Settings.

In the simulator, an approach-to-stall checking event may be maneuver-based or scenario-based with an entry altitude consistent with normal operating environments. The entry parameters, including W&B, should be within aircraft limitations to ensure adequate performance for recovery from initial indications of a stall. During training, the trainee may be asked to ignore some aural and visual indications of impending stall in order to practice the more difficult control movements needed to recover from the stick shaker. During checking, the trainee should be evaluated on recovering at the first indication of stall, even if it is based on an aural or visual indication, even if it occurs before the stick shaker or stick pusher (if installed).

Configurações Realistas.

No simulador, um evento de exame de aproximação-de-stall pode ser baseado em manobra ou baseado em cenário com uma altitude de entrada consistente em ambientes de operação normal. Os parâmetros de entrada, incluindo Peso & Balanceamento, devem estar dentro das consistentes limitações para assegurar performance adequada para recuperação de indicações inciais de um stall. Durante treinamento, o [piloto'em treinamento pode ser pedido para ignorar algumas indicações sonoras e visuais de iminente stall em ordem de praticar os mais dificeis movimentos de controle necessários para recuperar do aviso do Stick Shaker. Durante o exame, o piloto treinanedo deve ser avaliado na recuperação na primeira indicação de stall, mesmo se ela estiver baseada numa indicação sonora ou vsual, mesmo se ela ocorrer antes do [aviso] de Stick Shaker ou stick pusher (se instalado).

Air France 447 - New Findings - Recommendations - Pilots' Talkings

AIRBUS 330 - Controles de Voo

Principio Básico

As superfícies de controle de voo do A330 são:

 - Eletricamente controladas
 - Hidraulicamente ativadas

O estabilizador e o leme/direção podem ser mecanicamente controlados.

Os sidesticks são usados para pilotar a aeronave com leme e direção.
Os comandos dos pilotos, são interpretados pelos computadores, os quais enviam sinais para mover os controles de voo necessários para realizar o curso de voo desejado.
Apesar do comando dos pilotos, os computadores previnem:
 - manobras excessivas
 - que os limites da segurança de voo sejam excedidos

In a schematic manner, the threshold is stable below a Mach of the order of 0.3, then reduces in a quasi-linear manner to a Mach of the order 0.75, after which it falls more rapidly when the Mach increases up to Mach 0.82.

Onboard weather radar

The Air France Airbus A330’s are fitted with Collins WXR 700X-623 type weather radar with a flat antenna (P/N : 622-5132-623). The opening angle of the radar beam is 3.6° in elevation and 3.7° in azimuth.

Adjustments to the tilt and the gain are made manually.

Each airplane is equipped with two systems, only one antenna and only one control box.

Only one system is active at a time.

The radar image is presented on the ND overlaid with navigation and TCAS information. It is presented when the radar is operating, when the ND is not in PLAN2 mode and when the TERR3 mode is not selected. Range adjustment is done manually

.

Note: Adjusting the luminosity of the terrain and weather information is done independently of that of other information on each ND.

No malfunctions of the weather radar were reported on the other ATL of F-GZCP in the last 6 months prior to the accident.

Instructions for use of weather radar

In cruise mode above 20,000 feet, a slight downwards adjustment of tilt, depending on the scale selected, is recommended so that the ground echoes only appear on the ND at the edge of the furthest distance circles. This method enables the simple and practical application of the height/tilt rule of equivalence providing the optimum tilt adjustment.
When pilots monitor the weather situation, gain can remain in CAL position. In the confirmed
presence of storms and during their avoidance, a manual adjustment can be used for comparison with the CAL image.
A scale of 160 NM enables the change in the weather situation to be assessed and anticipate route changes. A scale of 80 NM is used for avoidance. Short scales must be periodically discontinued in order to observe distant weather conditions and to avoid an impasse amid the disturbances.
The shape of the echoes may alert the crew to the possible presence of hail. Zones of turbulence may be presented above a detected zone of precipitation.
Red or magenta zones as well as fringe-shape echoes must in this way be by-passed from windward by regularly adjusting the tilt and the range. The avoidance decision must be taken before the echoes are at 40 NM.

The operator recommends avoiding flying less than 5,000 ft above or below a storm cell. It provides a formula for pilots to estimate the separation height between the top of a detected cell and the airplane. This formula uses the distance and the tilt points from which the zone echo disappears. Above 23,000 ft, it is recommended to fly more than 20 NM from these zones11.

Time (UTC)	Captain & PNF	1st Officer (PF)
22:10	Cleared to Start Up
22:29		Take Off  (TOW = 232.8) TakeOff Weight Max. TOW = 233 Ton. Including Fuel = 70.4 Ton
01:35:15		Crew Informed ATLANTICO controller the aircraft passed INTOL Fix point and they estimated SALPU at 01:48 then ORARO at 02:00 UTC.
01:35:46		Controller asked them to maintain Flight Level 350 and the estimated time at TASIL Fix point.
01:35:53 to 01:36:14		Controller asked again three times for the estimated at TASIL Fix with no answer.
01:55:00	He woke the second copilot and said:	“…he’s going to take my place”
01:59:32 to 02:01:46	He attended the briefing between the two copilots	“the little bit of turbulence that you just saw we should find the same ahead we`re in the cloud layer unfortunately we can’t climb much for the moment because the temperature is falling more slowly than forecast” “the logon with DAKAR failed”
	The airplane approached the ORARO point maintaining Flight Level 350, MAC 0.82, Pitch Altitude 2.5°, Weight & Balance 205 Ton and 29%. Autopilot 2 and Auto-Thrust engaged.
02:06:04		Called cabin crew: “in two minutes we should enter an area where it’ll move about a bit more than at the moment, you should watch out” He added: “I’ll call you back as soon as we’re out of it”
02:08:07	“you can maybe go a little to the left …”	The airplane changed the heading 12 degrees to the left. Turbulence level increased slightly and the speed was reduced to MACH 0.80.
02:10:05	The AUTOPILOT and   AUTO-THURST disengaged
		Pilot Flying said: “I have the controls”
	The airplane began to roll to the RIGHT and the Pilot Flying made a nose-up and LEFT input. The STALL WARNING sounded 2 times in a row. The recorded parameters show a sharp FALL from about 275 Knots to 60 Knots in the speed displayed on the LEFT PFD, and then a few moments later in the speed displayed on the Integrated Standby Instrument System [ISIS]. There is no record on the Flight Data Recorder about speed displayed on the RIGHT side.
02:10:16		“we`ve lost the speeds then” He added: “alternate law protections”
	The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane start climb.
		PF made nose-down control inputs and alternately LEFT and  RIGHT  roll inputs.
	The vertical speed reached 7000 feet/min, dropped to 700 feet/min and roll varied between 12° RIGHT and 10° LEFT. The speed displayed on the LEFT side increased sharply to 215 Knots (MACH 0.68). The airplane was at 37500 feet and the recorded AOA was around 4°.
02:10:50	PNF tried several times to call the Captain back
02:10:51	The STALL WARNING triggered again. The TRUST levers were positioned in the TO/GA detent
		The Pilot Flying maintained nose-up inputs
	AOA [Angle Of Attack] was around 6° continued to increase. The Trimmable Horizontal Stabilizer [THS] began a movement and passed from 3° to 13° pitch-up in about 1 minute and remained in the latter position until the end of flight.
50 seconds later	The speed displayed on the ISIS increased sharply towards 185 Knots.
		The Pilot Flying continued to make nose-up inputs
	The airplane’s altitude reached its maximum of about 38000 feet.  AOA and pitch attitude reached 16°.
02:11:45	The Captain re-entered the cockpit
	During the following seconds all of the recorded speeds became invalid and the STALL WARNING stopped.
	The altitude was then about 35000 feet, the AOA exceeded 40° and the Vertical Speed was about  minus 10000 feet/minute. The airplane’s pitch attitude did not exceed 15° and the engines’ N¹ were close to 100%. The airplane was subjected to roll oscillations that reached 40°.
		The Pilot Flying made input on the Side-stick to the LEFT and nose-up stops, wich lasted about 30 seconds.
02:12:02		PF said: “I have no more displays”
	PNF said: “we have no valid indications”
	The Thrust levers were on IDLE detent, at that moment, and the engines’ N¹ were at 55%.
50 seconds later	PF made pitch inputs.
	The AOA decreased, the speeds became VALID again and the STALL WARNING triggered again
02:13:32	PF said: “we’re going to arrive at level one hundred”
15 seconds later	Simultaneous inputs by both pilots on the side-sticks were recorded
		PF said: “go ahead you have the controls”
	AOA, while it was valid, always remained above 35°
02:14:28	The last recorded values were a Vertical Speed of minus 10912 feet/minute, a Gorund Speed of 170 Knots, Pitch Attitude of 16,2° nose-up, Roll Angle of 5.3° LEFT and a Magnetic Heading of 270°
	No EMERGENCY message was issued by the crew
	The wreckage was found at a depth of 3980 meters on 03 APR 2011 at about 6.5 Nautical Miles and to the North of the last position transmitted by the aircraft

The following tracks were recorded:

 track 1: radio communications and the signal from the microphones for the pilot seated on the left
 track 2: radio communications and the signal from the microphones for the pilot seated on the right
 track 3: radio communications, the signal from the second copilot’s microphone (rear seat), and the FSK signal
 a track made up from the first 3 tracks mixed together
 CAM track: the signal from the cabin area microphone

Analysis of the 5 audio files downloaded revealed that the event did not occur at the end of the sequence of data recorded on the 5 tracks, and that the tracks lasted for less than a few dozen seconds at the expected values.

Synchronisation of the various channels showed that some of the data was missing.
Moreover, analysis of the binary contents of the EEPROM memory confirmed the inconsistency of the pointers5 used by the manufacturer’s reader to start and end the downloading of the data.

Analysis of the flight recorder data

 Synchronisation of the recorders
The recorders were synchronised using the various alarms triggered during the flight, particularly the stall warning. The number of alarms made it possible to synchronise the recorders with an accuracy of approximately 100 ms.

The CVR recording started at about 0 h 09 UTC on 1 June.

 CVR analysis
The CVR audio recording starts at 00 h 09 min 15. The cockpit door was opened once at 0 h 26 min 19. It was later closed and opened again several times. It stayed opened for some time on several occasions. The door security system (electrical opening command by the pilots) was not heard on the overall recording.
At 0 h 36 min 26, an electrical phenomenon (audio discharge) linked to atmospheric conditions appeared on the CAM track and could be heard until the end of the recording. The following figure shows the distribution of those audio discharges as a function of time:

CONCLUSIONS

New Findings
 the composition of the crew was in accordance with the operator’s procedures,
 the airplane’s weight and balance were within operational limits,
 at the time of the autopilot disconnection, the Captain was taking a rest,
 the departure of the Captain was done without leaving any clear operational instructions, in particular on the role of each of the copilots,
 the crew had identified some echoes on the weather radar,
 the crew made a heading change of 12° to the left of its route,
 the AP disconnected while the airplane was flying at the upper limit of a slightly turbulent cloud layer,
 the copilots had not received any training, at high altitude, in the “Unreliable IAS” procedure and manual aircraft handling,
 there was an inconsistency between the speeds measured, likely following the blockage of the Pitot probes in an ice crystal environment,
 although having identified and called out the loss of the speed indications, neither of the two copilots called the procedure “Unreliable IAS”,
 the invalidity of the speed displayed on the left PFD lasted for 29 seconds, that of the speed on the ISIS for 54 seconds,
 in less than one minute after the autopilot disconnection, the airplane exited its flight envelope following inputs that were mainly pitch-up,
 the Captain came back into the cockpit about 1 min 30 after the autopilot disconnection,
 throughout the flight, the movements of the elevators and the THS were consistent with the pilot’s inputs,
 up to the exit from the flight envelope, the airplane’s longitudinal movements were consistent with the position of the flight control surfaces,
 there was no explicit task-sharing between the two copilots,
 there is no CRM training for a crew made up of two copilots in a situation with a relief Captain,
 no standard callouts were made on the disparities in pitch attitude and vertical speed,
 the airplane’s angle of attack is not directly displayed to the pilots,
 the approach to stall was characterised by the triggering of the warning then the appearance of buffet,
 neither of the pilots made any reference to the stall warning,
 neither of the pilots formally identified the stall situation,
 the stall warning was triggered continuously for 54 seconds,
 a short time after the triggering of the stall warning, the PF selected TO/GA thrust and made a nose-up input,
 the angle of attack is the parameter that allows the stall warning to triggered; if the angle of attack values become invalid, the warning stops,
 by design, when the measured speed values are lower than 60 kt, the 3 angle of attack values become invalid,
 each time that the stall warning triggered, the angle of attack exceeded the value of its theoretical trigger threshold,
 the engines functioned normally and always responded to the crew’s inputs,
 no announcement was made to the passengers.

Recommendations on Operations

Training for Manual Aircraft Handling

The investigation brought to light weaknesses in the two copilots: the inappropriate inputs by the PF on the flight controls at high altitude were not noted by the PNF through an absence of effective surveillance of the flight path. The stall warning and the buffeting were not identified either. This was probably due to a lack of specific training, although in accordance with regulatory requirements. Manual airplane handling cannot be improvised and requires precision and measured inputs on the flight controls. There are other possible situations leading to autopilot disconnection for which only specific and regular training can provide the skills necessary to ensure the safety of the flight. Examination of their last training records and check rides made it clear that the copilots had not been trained for manual airplane handling of approach to stall and stall recovery at high altitude.

Consequently, the BEA recommends:

 that EASA review the content of check and training programmes and make mandatory, in particular, the setting up of specific and regular exercises dedicated to manual aircraft handling of approach to stall and stall recovery, including at high altitude.

Relief Captain

The investigation showed that an absence of training and practice for a crew consisting of two copilots does not guarantee a level of performance equivalent to a crew consisting of a Captain and a copilot when faced with a degraded situation. The absence of a hierarchy and of effective task-sharing in the cockpit strongly contributed to the low level of synergy. The anxiety generated by the absence of the Captain from the cockpit shows that the two copilots were not capable of resolving this emergency situation. This can be explained both by the absence of any appropriate training and a lack of decision-making practice on the part of the two copilots. Numerous events turned out favourably due to the presence of the Captain whose training and experience made possible a more solid analysis and more serenereactions to the situation.

Recommendations relating to Certification

Angle of Attack Measurement

The crew never formally identified the stall situation. Information on angle of attack is not directly accessible to pilots. The angle of attack in cruise is close to the stall warning trigger angle of attack in a law other than normal law. Under these conditions, manual handling can bring the airplane to high angles of attack such as those encountered during the event. It is essential in order to ensure flight safety to reduce the angle of attack when a stall is imminent. Only a direct readout of the angle of attack could enable crews to rapidly identify the aerodynamic situation of the airplane and take the actions that may be required.

Consequently, the BEA recommends:

 that EASA and the FAA evaluate the relevance of requiring the presence of an angle of attack indicator directly accessible to pilots on board airplanes.

Recommendations relating to Flight Recorders

Analysis of the FDR parameters and audition of the CVR provide information that is essential to an understanding of the event. However, it is difficult to reconstruct the indications that were available to the crew on their instrument panel, especially the instructions given by the Flight Director crossbars when they reappear. It is also impossible to see whether there have been any attempts to re-engage the autopilot. A view of the instrument panel would complete the information provided by the FDR and the CVR and would make it possible to confirm the indications that were available to the crew and the actions that they made. Numerous recommendations have already been made on this subject over the past ten years without any real progress having been made.