[alpha1]

“The guy outside is knocking lightly on the door, and there is no answer,” the investigator said. “And then he hits the door stronger, and no answer. There is never an answer.”
He said, “You can hear he is trying to smash the door down.”

Call me naive, but I being a novice passenger flier can easily make out when the airplane starts descent or ascent.



The captain of the flight walks off the cockpit and doesn't realize that the plane is losing altitude?


What looks like is this perhaps, the captain leaves for toilet, something happens to the co-pilot, captain realizes something is amiss since the flight is losing altitude, tries to smash down the door. Too late to do anything now.

[Soumyajit9]

Originally Posted by alpha1

Call me naive, but I being a novice passenger flier can easily make out when the airplane starts descent or ascent.
The captain of the flight walks off the cockpit and doesn't realize that the plane is losing altitude?
What looks like is this perhaps, the captain leaves for toilet, something happens to the co-pilot, captain realizes something is amiss since the flight is losing altitude, tries to smash down the door. Too late to do anything now.

The TOI reports states that air safety experts have quoted one of the theories as....

Among the theories that have been put forward by air safety analysts not involved in the investigation is the possibility that a pilot could have been incapacitated by a sudden event such as a fire or a drop in cabin pressure.

[rohanjf]

I thought all modern jets have keypads to unlock the cockpit doors from outside. Enter the 6 or 8 digit key on the keypad attached to the door from outside, and you get an entry into cockpit. Is that not the case?

[Soumyajit9]

I think they have manual bolts like the bathroom doors in an aircraft.
The hi-fi keypad would be probably on a Dreamliner. This was a budget aircraft.

[phamilyman]

Originally Posted by alpha1

The captain of the flight walks off the cockpit and doesn't realize that the plane is losing altitude?


What looks like is this perhaps, the captain leaves for toilet, something happens to the co-pilot, captain realizes something is amiss since the flight is losing altitude, tries to smash down the door. Too late to do anything now.

Theory 1: controlled descent aka pilot suicide on the lines of LAM.
Link:(repeatedly acknowledged by many on pprune as sounding reasonable)

The questions are whether this aircraft went fast enough to activate the high speed protections? If it did, why didn't it pitch up, and what was it doing flying so fast in the first place?

If pilot incapacitation occurred, why did the Auto-pilot maintain maximum possible speed, and why did it not capture an altitude selected on the FCU?

The standard drill for an emergency descent involves keeping the autopilot engaged if possible, dialing a lower FCU altitude, turning off the airway and commencing the descent by selecting Open Des.

The aircraft continued on track but commenced descending at maximum speed, so none of that appears to have been done. Unless there was a massive un-correctable error in the Auto-flight system, there had to be pilot intervention to get it to do that.

This is a very strange accident.

Originally Posted by Soumyajit9

I think they have manual bolts like the bathroom doors in an aircraft.
The hi-fi keypad would be probably on a Dreamliner. This was a budget aircraft.

Nope - they supposedly had the keypad door, but the keypad doesnt work as you think. Not as per pprune:

1) The cockpit door keycode is used to call the flight deck to open the door. At that point a pilot would verify the person trying to access the cockpit and only then swictch a switch to "release" the magnetic locks securing the door closed.

2) If the "in cockpit" pilot is unconcious while the other is out of the cockpit, a different code can be entered from the outside with a timer delay which would auto open the door if not permanently locked (using the deadbolt) by the pilot inside the cockpit. (This timer delay is there to allow a number of seconds to pass with the buzzer sounding in the cockpit for the "incapacitated" pilot to open the door using the console switch. Should the incapacitated pilot not open the door then the normal (magnetised) door locks would automatically open after the timer has expired.

3) Should any of the codes be used to try to gain access to the cockpit then, a lock door (spring loaded) switch can be held in the cockpit by a pilot until the "deadbolt" is put on to prevent the entry into the cockpit. To put the deadbolt on and prevent permanent access to the cockpit, a pilot has to get out of his seat normally and "slide/move" the deadbolt across the door preventing any access if the door was tried to be opened.

If the deadbolt was pushed across the door from the inside of the cockpit then, no matter what normal actions someone takes from outside the door, you will not be able to gain access.

As someone else said - its puzzling, If the FO (first officer) was incapacitated, who initiated the descent? That he just happened to be incapacitated to press hard enough on the stick to start a descent but not hard enough to enter a dive or change heading doesn't sound feasible.

Interestingly, what happened there is against the Standard Operating Procedures of US airlines atleast:

Regarding the aforementioned procedure of having a flight-attendant enter the cockpit and guard the door when a pilot steps out, all US airlines do this and I assume(d) it was standard around the world. Simply because yes, there should be someone up there to open the deadbolt if Copilot Chucky drops dead while Skipper Steve is back in the WC. The leftover pilot is also legally required to (in the USA) be WEARING his oxygen mask while he is up there alone at typical cruise altitudes.

Or it may be something as simple as human stupidity such as using an SLR while alone in the cockpit! (page 2).

[Jeroen]

The standard Operating Procedures for US Airlines, to the best of my knowledge, is just that. I'm not aware of any other carrier using the procedure where a flight attendant enters the cockpit if one of the pilots needs to step out.

Jeroen

[SnS_12]

Well, this just came up on TOI

"Co-pilot in Germanwings crash was in total control of plane, locked out and deliberately crashed plane as per French officials. "

[sdp1975]

I still find the claim made by the French Prosecutor hard to believe, that the co-pilot crashed the plane deliberately. He made a very sensational statement, but did he get it right in about 2 days of investigation ? Or was more time and investigative effort needed to reach to a conclusion ? Only time will tell.

[joe1980]

Originally Posted by sdp1975

I still find the claim made by the French Prosecutor hard to believe, that the co-pilot crashed the plane deliberately. He made a very sensational statement, but did he get it right in about 2 days of investigation ? Or was more time and investigative effort needed to reach to a conclusion ? Only time will tell.

Quoting from what was posted at BBC: http://www.bbc.com/news/world-europe-32063587

To make a descend, there has to be some switch or knob be activated and this seems to have been happened deliberately. This makes me believe that the claim made by the French authorities to be true! Only a detailed investigation could reveal what has actually happened!

[govindremesh]

This is shocking. If proved, this incident would join the club of Egypt Air 990 and Silk Air 185.
Reading both the incidents, The Silk Air 185 investigation revealed that the Cockpit Voice Recorede (CVR) and the Flight Data Recorder (FDR) were deliberately switched off by pulling out the circuit breaker that powers them.

If this pilot indeed was suicidal, why did he not do the same action to destroy evidence? Or was it that he wanted the world to know that he deliberately put the aircraft down?

Further, the passengers of United 93 were able to break open the cockpit door and overpower the hijackers. The Germanwings passengers had more than 10 minutes, why were they not able to break open the door once the captain was locked out?

So many questions to be answered!

[Jeroen]

Originally Posted by sdp1975

I still find the claim made by the French Prosecutor hard to believe, that the co-pilot crashed the plane deliberately. He made a very sensational statement, but did he get it right in about 2 days of investigation ? Or was more time and investigative effort needed to reach to a conclusion ? Only time will tell.

Time will tell. But authorities tend to be very reluctant to come out with anything pertaining to aviation accidents. They want to get it right. So the fact that they did come out so soon, is probably a very good indication that they believe they are right. There is nothing for them to gain.

Also, as pointed out, it takes several deliberate and specific actions from the pilot to put the plane into this steep auto-pilot descent. You have to reset the altitude and activate some mode of vertical descent. So at the bear minimal two very specific and deliberate actions.

Jeroen

[prakhar1998]

One fact all of us are forgetting is that a distress signal was sent moments before the crash. This signal couldn't have been sent without entry into the cockpit. It is highly unlikely that this was deliberate. I don't know what really happened, but I am not keeping any terrorist links aside. Maybe, their was a third person involved in the cockpit.

[Jeroen]

Originally Posted by prakhar1998

One fact all of us are forgetting is that a distress signal was sent moments before the crash. This signal couldn't have been sent without entry into the cockpit. It is highly unlikely that this was deliberate. I don't know what really happened, but I am not keeping any terrorist links aside. Maybe, their was a third person involved in the cockpit.

What distress signal? Earlier on there was some speculation that a Mayday call was made, but I have not seen any confirmation on that from any of the authorities

[n_ramesh99]

Originally Posted by govindremesh

This is shocking. If proved, this incident would join the club of Egypt Air 990 and Silk Air 185.
Reading both the incidents, The Silk Air 185 investigation revealed that the Cockpit Voice Recorede (CVR) and the Flight Data Recorder (FDR) were deliberately switched off by pulling out the circuit breaker that powers them.

Please note that the Silk Air 185 investigation result is disputed. In fact a court in US ruled that the accident happened due to equipment failure and not pilot actions. Not so sure about the Egypt Air 990, though that is also disputed and suicide theory is not proved beyond doubt. One thing we should keep in mind is that these theorems seems to be raised by parties with vested interest, namely aircraft manufacturers.

One thing I failed to understand is why should a pilot commit suicide by killing his passengers! I agree they do propose a reason in case of Egypt Air 990. Not sure how does the French authorities come to such a conclusion with a mere two days of investigation.

[gsurya]

Originally Posted by govindremesh

This is shocking. If proved, this incident would join the club of Egypt Air 990 and Silk Air 185.
Reading both the incidents, The Silk Air 185 investigation revealed that the Cockpit Voice Recorede (CVR) and the Flight Data Recorder (FDR) were deliberately switched off by pulling out the circuit breaker that powers them.

If this pilot indeed was suicidal, why did he not do the same action to destroy evidence? Or was it that he wanted the world to know that he deliberately put the aircraft down?

Further, the passengers of United 93 were able to break open the cockpit door and overpower the hijackers. The Germanwings passengers had more than 10 minutes, why were they not able to break open the door once the captain was locked out?

So many questions to be answered!

Post 9/11 changes were made to cockpits so that CVR/FDR could NOT be tampered with by anyone & cockpit doors were strengthened tremendously so that they could not be broken down.

In fact its now being suggested that the new locking techniques that allowed pilot to totally isolate & lock the cockpit contributed to this disaster!

Ultimately, if a pilot/driver/captain WANTS to crash/sink the vehicle they are piloting, no system can always prevent it.