El amigo Cactus me ha pasado este enlace con una entrevista con Denis Yevdokimov, piloto del SSJ accidentado en mayo de 2019. En el enlace se puede leer sumario en inglés.
El resultado final de la investigación no se ha publicado, pero todo apunta que se culpará al piloto por sus acciones. Tras recibir el impacto del rayo sus acciones fueron inadecuadas, y causaron la desintegración y la ignición del avión.
El resultado final de la investigación no se ha publicado, pero todo apunta que se culpará al piloto por sus acciones. Tras recibir el impacto del rayo sus acciones fueron inadecuadas, y causaron la desintegración y la ignición del avión.
En la entrevista Yevdokimov defiende que tras pegar el rayo el avión se volvió incontrolable, y su comportamiento era muy diferente al del simulador donde se practica esta situación. Tomó la decisión de aterrizar porque temía que más sistemas fallasen.
Básicamente lo que ocurrió fue que el rayo inutilizó el sistema "Fly by wire" y el sistema de radio principal. Por ello Yevdokimov tuvo que volar en modo "directo", más complicado.
Hasta este punto está todo claro. El problema es que el avión acababa de despegar y su peso estaba por encima del máximo al aterrizaje. La tripulación tampoco respondió a los avisos de viento comunicados por los controladores, ni a la orden de realizar otro circuito.
Fuentes y enlaces de interés:
- https://www.youtube.com/watch?v=81oA_U51gNw
- http://www.rusaviainsider.com/
- https://mak-iac.org/upload/iblock/4e4/report_ra-89098_pr.pdf (investigación preliminar, en ruso)
- https://mak-iac.org/upload/iblock/4e4/report_ra-89098_pr.pdf (investigación preliminar, en ruso)
Apéndice 1: Transcripción de la entrevista en inglés
Question: Let's try to recreate the events of May 5th. What was the weather like, did it even make sense to take off? Who made the final decision to start flying that day?
Evdokimov: The weather was not unusual. The received meteorological information met the requirements when deciding on a flight. Being on the runway, I was guided by the weather information and inspected the space in the direction of take-off to establish the absence of dangerous weather phenomena, which I noticed the second pilot. The final decision on take-off, on continuing the flight, on landing, in any case, is made by the aircraft commander (FAC). Accordingly, I, as the PIC on that flight, decided to take off and start the flight.
Q: A lightning bolt hit the plane. Management switched to manual mode, the so-called Direct mode. Is this a regular story in principle?
Evdokimov: Lightning striking an airplane is not uncommon, but, as a rule, it does not lead to disruption of aircraft systems. In the same flight, the discharge of atmospheric electricity disabled one of the most important aircraft systems, namely the control system. The remote control system on the Superjet is completely electric, that is, it does not have redundant mechanical communication between the steering controls. Neither the investigation authorities, nor the IAC (International Aviation Committee) I was not interested in the fact that atmospheric electricity was affected by the aircraft, there is simply not a word about this in the case file, with the exception of the testimonies of passengers and crew. I can assume that this circumvention of an important fact is associated with eliminating the risk to the reputation of the manufacturer Superjet.
Q: Have you had experience managing Superjet in Direct mode? Was this mode practiced during training?
Evdokimov: Direct mode is practiced during retraining for the type of aircraft and then - in accordance with the training program approved by the aviation authorities. There are no training flights on a real aircraft in this mode.
Q: Did the control in reality differ from the control on the simulator?
Evdokimov: control in this mode on the simulator does not cause difficulties. In flight on May 5, control of the aircraft in this mode was very different from the simulator.
Q: Why did you decide to return, and did not continue the flight to Murmansk?
Evdokimov: Further flight to Murmansk was not possible, since in Direct mode flight can only be performed at low altitudes, which leads to an increase in fuel consumption. There was no additional reserve needed during that flight. Numerous failures displayed on the aircraft display also did not allow a decision to continue the flight to the destination airport, since it was not possible to determine the degree of aircraft malfunction in flight.
Q: Why did you decide not to circle over the airport to generate fuel, but to sit down with full tanks? Didn't this create a potential emergency?
Evdokimov: The decision was made on the basis of fear of losing the ability to control the aircraft in general. As I said earlier, exposure to atmospheric electricity does not lead to failure of aircraft systems, in our case, violations were observed. If this was the effect of a discharge that exceeded certification values in terms of power, then being in the air could lead to a cascade increase in failures in aircraft systems, which would lead to a complete loss of controllability.
Q: When approaching, judging by the published records, you say the phrase: “Yes, what is it? Plus or minus 200 feet. ” What does this phrase mean?
Evdokimov: When performing a horizontal flight, I noted a difficulty in accurately maintaining a given height.
Q: The representative of the Investigative Committee claims that the aircraft adequately responded to the actions of the pilot. You, in turn, said, according to your lawyer, that the plane threw sideways. So what exactly happened to the handling of the plane?
Evdokimov: Yes, but he does not say that at the time of charging me with the case, there was at least some interpretation of the flight parameters, not to mention a detailed analysis of the actions and reactions of the aircraft to control actions. Particularly noteworthy is the fact that investigators limited themselves to filing a file from an emergency recorder that does not record an exhaustive amount of flight information, while the IAC also uses a file from a second operational recorder, which contains a complete list of information, including about Failures of aircraft systems. When landing, the response of the aircraft to control actions became the opposite, that is, when the control stick was rejected, the aircraft did not raise its nose.
Evdokimov: The weather was not unusual. The received meteorological information met the requirements when deciding on a flight. Being on the runway, I was guided by the weather information and inspected the space in the direction of take-off to establish the absence of dangerous weather phenomena, which I noticed the second pilot. The final decision on take-off, on continuing the flight, on landing, in any case, is made by the aircraft commander (FAC). Accordingly, I, as the PIC on that flight, decided to take off and start the flight.
Q: A lightning bolt hit the plane. Management switched to manual mode, the so-called Direct mode. Is this a regular story in principle?
Evdokimov: Lightning striking an airplane is not uncommon, but, as a rule, it does not lead to disruption of aircraft systems. In the same flight, the discharge of atmospheric electricity disabled one of the most important aircraft systems, namely the control system. The remote control system on the Superjet is completely electric, that is, it does not have redundant mechanical communication between the steering controls. Neither the investigation authorities, nor the IAC (International Aviation Committee) I was not interested in the fact that atmospheric electricity was affected by the aircraft, there is simply not a word about this in the case file, with the exception of the testimonies of passengers and crew. I can assume that this circumvention of an important fact is associated with eliminating the risk to the reputation of the manufacturer Superjet.
Q: Have you had experience managing Superjet in Direct mode? Was this mode practiced during training?
Evdokimov: Direct mode is practiced during retraining for the type of aircraft and then - in accordance with the training program approved by the aviation authorities. There are no training flights on a real aircraft in this mode.
Q: Did the control in reality differ from the control on the simulator?
Evdokimov: control in this mode on the simulator does not cause difficulties. In flight on May 5, control of the aircraft in this mode was very different from the simulator.
Q: Why did you decide to return, and did not continue the flight to Murmansk?
Evdokimov: Further flight to Murmansk was not possible, since in Direct mode flight can only be performed at low altitudes, which leads to an increase in fuel consumption. There was no additional reserve needed during that flight. Numerous failures displayed on the aircraft display also did not allow a decision to continue the flight to the destination airport, since it was not possible to determine the degree of aircraft malfunction in flight.
Q: Why did you decide not to circle over the airport to generate fuel, but to sit down with full tanks? Didn't this create a potential emergency?
Evdokimov: The decision was made on the basis of fear of losing the ability to control the aircraft in general. As I said earlier, exposure to atmospheric electricity does not lead to failure of aircraft systems, in our case, violations were observed. If this was the effect of a discharge that exceeded certification values in terms of power, then being in the air could lead to a cascade increase in failures in aircraft systems, which would lead to a complete loss of controllability.
Q: When approaching, judging by the published records, you say the phrase: “Yes, what is it? Plus or minus 200 feet. ” What does this phrase mean?
Evdokimov: When performing a horizontal flight, I noted a difficulty in accurately maintaining a given height.
Q: The representative of the Investigative Committee claims that the aircraft adequately responded to the actions of the pilot. You, in turn, said, according to your lawyer, that the plane threw sideways. So what exactly happened to the handling of the plane?
Evdokimov: Yes, but he does not say that at the time of charging me with the case, there was at least some interpretation of the flight parameters, not to mention a detailed analysis of the actions and reactions of the aircraft to control actions. Particularly noteworthy is the fact that investigators limited themselves to filing a file from an emergency recorder that does not record an exhaustive amount of flight information, while the IAC also uses a file from a second operational recorder, which contains a complete list of information, including about Failures of aircraft systems. When landing, the response of the aircraft to control actions became the opposite, that is, when the control stick was rejected, the aircraft did not raise its nose.
Este comentario ha sido eliminado por el autor.
ResponderEliminarEste comentario ha sido eliminado por el autor.
ResponderEliminarEs muy extraño ese accidente, Yevdokimov es alto oficial de la fuerza aérea (no me acuerdo si mayor o teniente-coronel), tiene experiencia de 10 años como comandante de Il-76 en la VTA. No es un inexperto, voló un avión analógico (sin FBW) en condiciones muy duras: la VTA practica vuelos a muy bajas alturas, aterrizajes y despegues en ángulos muy elevados para evitar ataques de MANPADs, vuelos en malas condiciones meteorológicas y sin visibilidad, etc. Por eso, hay errores que la tripulación cometió que no se entienden. Por ejemplo, una de las radios fue dañada, pero la otra funcionaba normalmente, y la tripulación tardó hasta verificar y darse cuenta de eso, quedando bastante tiempo incomunicada con el control. Además, hubo alerta por cortante de viento (wind shear), escuché la grabación de las conversaciones en cabina y se escucha varias veces la alarma, y el procedimiento en este caso es de abortar el aterrizaje, sin embargo decidieron continuar, con el agravante que el avión estaba muy pesado. Según el MAK (el órgano de aviación civil ruso), ni el tren de aterrizaje de un Il-76 (que es mucho más grande y fue diseñado para operar en condiciones mucho más duras) aguantaría la fuerza del impacto del aterrizaje hecho por Yevdokimov, donde el avión rebotó dos veces.
ResponderEliminarPero estoy de acuerdo en que puede haber problemas con el diseño del avión. En primer lugar, Sukhoi debería revisar la protección contra relámpagos, ya que esos no deberían causar fallas importantes como el FBW y las comunicaciones. También revisar el direct mode, porque los movimientos que hacía Yevdokimov eran muy fuertes, muchas veces el tiraba del joystick de un extremo a otro (por lo que vi en la grabación de los comandos), eso no debería ser así, quizás el relámpago también afectó los sistemas eléctricos de accionamiento de las superficies de control, dejando el avión mucho más difícil de volar. Espero que no vayan a culpar totalmente la tripulación sin investigar todo eso, ya que pueden volver a causar problemas en el futuro.
Creo que el piloto es muy honesto al decir que su decisión de aterrizar de inmediato el avión la hizo por "el miedo a perder el control" de la aeronave.
ResponderEliminarPucha, es difícil situarse en su lugar. Es una decisión que tomó en un segundo. Vio que le costaba controlar el avión en manual y tenía que decidir rápido. O aterrizar o confiar en que podría seguir controlando la aeronave. ¿qué habrían hecho ustedes?
Ahora, si lo vemos de afuera es bastante evidente que el avión, hasta ese momento, no perdió el control.
Pd. Alejandro, jaja, no me quemes con la transcripción que no hice.. saludos.
¡Lo siento Cactus! Luego lo cambio. Saludos.
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