View Full Version : A question about evacuations
4th Jun 2012, 15:46
Perhaps a slightly unusual question from a passenger, but could someone explain to me what the 'order of events' is in the immediate stages of an evacuation? Don't want to discuss the merits/problems of one, that's been done elsewhere. Am just interested to know the logistics of it.
Let's say that the aircraft is taxiing to/from the runway and the captain decides to evacuate the aircraft. There is nothing discernible to the passengers in the cabin that an evacuation will be ordered. Everything 'seems' normal, then one is ordered. What happens?
1) Would the first thing that we, passengers, hear in the cabin be the captain making the evacuation call over the PA system?
2) Is this the type of wording that is used: 'This is the captain. This is the captain. This is an emergency. Evacuate. Evacuate. Evacuate. [Left/right-side only])?
3) Or would we (or rather those that notice) hear the engines being shut down first?
4) Are the seat-belt signs switched off? (Not that people observe them anyway, especially in the case of an evacuation I imagine!).
5) Sometimes the flight deck PAs are barely audible (at least on my last flight, I had to strain my ear to the speaker). Can I take it you use a pretty loud voice to avoid such an issue?
It's a company specific question....
However roughly speaking.
As soon as the flight deck crew are aware of a problem that may lead to an evacuation a PA will be made "Attention crew at station"
The aircraft would be brought to a stop the Captain would decide if an evacuation was required, if so the checklist would be actioned. (resulting in the engines being shut down)
Then a command would be given to evacuate (this depends on the airline exactly how it is given)
That would be it the evacuation has started and the cabin staff will make sure all passengers leave the aircraft promptly and safely.
4th Jun 2012, 21:15
Well, company specific to a point, but in general...
The aeroplane will come to a stop, or be at a stop. The stop may be normal, urgent or perhaps violent depending on circumstances. There may be no prior indications whatsoever.
There will be a considerable pause while the flight deck get their actions started, this will seem interminable if the event was an obvious problem or if there is external fire. In reality it will last a couple of tens of seconds.
The engines will shut down (you cannot evacuate pax into running engines)
A PA will be made to the effect of "EVACUATE EVACUATE! UNFASTEN YOUR SEATBELTS AND GET OUT"
Then there will be a few moments - long long moments while the cabin crew deal with the "Oh shit! Oh Christ! Oh dear!" moments, get up, check outside their doors, open them ans begin to scream, and won.t stop screaming "COME THIS WAY! COME THIS WAY! JUMP! JUMP! COME THIS WAY! LEAVE YOUR BAGS! JUMP! COME THIS WAY" etc etc until exhausted or all the pax are off.
It will be very noisy with their shouting which led to scurrilous reports in the meeja recently of crew panicking during an evac. They were doing their job,
overwhelming all the senses of the pax with urgency to get off the aircraft.
Then they're supposed to Marshall hundreds of bewildered and disorientated pax (ie far far more bewildered ans disorientated than usual) and get them out of the way of the hordes of adrenaline fuelled emergency vehicles thundering into the area at breakneck speed...
They earn every penny of their meagre wages, believe me, and they don't get paid one penny for the day that have to do an evac IMHO.
A well managed evac will seem to take forever to get started, The pauses will seem like a lifetime if there is obvious urgency to leave but scores, even hundreds of such events have conclusively shown that hurried evacs cost lives, it is far far better to be methodical and take time to get the sequence of events right than rush it and bugger it up, and kill more people than might otherwise have been the case. Its a very serious business indeed and MUST be got right, there's no second chance.
but could someone explain to me what the 'order of events' is in the immediate stages of an evacuation?
Exact sequence may vary from airline to airline and from one aircraft to another, but the basic sequence is along the lines of:
1. Parkbrake set ( because we want to make sure we're stopped and stay stopped)
2. Shutdown the engines. ( Don't want people being sucked into engines or blown away by jetblast)
3. Initiate the evacuation using the PA, warning of any hazards if appropriate, and then also trigger the evacuation alarm. Alert ATC/Ground crew.
The seatbelt sign gets left alone. If you don't hear the PA from the Flight Deck, you would certainly hear the evacuation alarm..and you would most certainly hear the cabin crew...
8th Jun 2012, 17:08
Thank you for taking the time to reply. Very helpful and interesting.
So, do all modern commercial airliners (B737, A320, B747 etc.) have an evacuation alarm that sounds in the cabin? What does it say? 'Evacuate, evacuate'?
9th Jun 2012, 21:56
For us, the sequence of events would be a follows:
Following an unpleasant event - and realistically we are talking about smoke, fire or their imminent threat, the aircraft would be brought to a stop. I'd the order "Cabin Crew, Passengers - Remain seated."
Assuming time is available, we would both agree that an evacuation is the most sensible thing to do. If it was, we'd action the following memory items:
Set Parking Brake; Lower Flaps (or raise them one notch if they were at Full), Shut down both engines (the cabin lights lights would now go out and the Emergency Lights would illuminate); Pull and twist the engine fire handles (firing their fire extinguishers); Shut down the APU; Fire the APU fire bottle; Dump the Cabin Pressure.
I'd then order "Evacuate Aircraft" and my colleague would inform ATC. The Cabin Crew would then step in and do their job - and that would be pretty memorable! The doors would be opened and slides deployed and they will SHOUT AT YOU! You'd then leave - pronto, even if just to get away from the noise.
In the relative calm of the cockpit, we'd run through the Evacuation Checklist, turn off the batteries and then leave ourselves. My colleague through the front door and me through the rear.
11th Jun 2012, 11:29
Piltdown Man, when you say...
and then leave ourselves. My colleague through the front door and me through the rear.
...do I take this to mean that you are a captain and that, in such a role, you are expected/expect to leave the aircraft from the rear door in order to pass through the cabin first to check that all passengers and cabin crew have left before you? Is this a standard procedure or is it simply considered good command etiquette?
11th Jun 2012, 21:57
Its standard procedure in our airline and most others I suspect although the point is made that you should consider the risk to yourself before doing so.
12th Jun 2012, 09:08
Ours just tell us to help with evacuation if necessary and without any additional risk to our health, else open the windows and get out. Since we are wired to get out of the plane asap from other training venues that probably will be the first thing we do though, just get out of the window and then check on the rest.
12th Jun 2012, 11:05
In the relative calm of the cockpit, we'd run through the Evacuation Checklist, turn off the batteries and then leave ourselves.
Caution: One persons personal opinion only!
I understand that the Boeing (737, anyway) evacuation requires the checklist to be read first (not last) while the people down the back sweat it out wondering what is going on up front. By the time the checklist is actuated one item at a time and things are getting real smokey down the back if it is a fire, then up to a minute or more will have passed. The original idea for sixty years plus was the pilots must know the evacuation sequence off by heart and can rip through it fast in order to give the passengers a better chance of getting out before smoke/fire gets them first.
But the powers that be decided pilots are not to be relied upon to remember a typical 8 items anymore and now they are told what to do by a checklist. Shows you how bad the education system is in schools nowadays when you can't remember 8 simple actions. :E
Too bad if the smoke in the cockpit is too thick to read a checklist and the crew are forced to rely on their memory.
Interesting thing is that most pilots may only get one practice evacuation in the simulator once a year and yet will practice a dozen or more engine failures during take off in a year. This suggests that the Evacuation is given a much lower priority in training than engine failures?
13th Jun 2012, 07:26
Really?! The evacuation check-list is not a memory check-list? Why on earth not? There are other safety critical check-lists that are done by memory, are there not? Why not the evacuation one? Surely an evacuation is an example of a situation where speed is of the absolute essence and could save lives? Pilots have to work through other emergency check-lists quickly and accurately, so why not for evacuations?
Lord Spandex Masher
13th Jun 2012, 08:05
Unfortunately, with people ripping through it fast critical items were being missed. Consistently.
It is better to take a few more seconds and ensure that everything that needs to be done is done. The time difference between a memory checklist and a read and do checklist is negligible.
Having said that I have memorised the evacuation checklist, just in case.
13th Jun 2012, 09:23
I take your point, LSM.
And I imagine a lot of commanders do have it memorised!
13th Jun 2012, 10:18
And the checklist is on the backside of the QRH, so if you take it out and just turn it around you have the checklist right there, no need to go looking for it.
However, since i was required to have it memorized in times gone by i still have it memorized. It is however quite amazing how much noise will be generated during an evacuation which can lead one to missing something, so going by the checklist is not quite that bad.
13th Jun 2012, 11:18
Plus the fact that the idea of other recall checklists is that they are backed up by the paper version at a suitable time to make sure nothing was missed - not really doable in an evac!
13th Jun 2012, 11:40
Supplementary question - does one of the CC go down the slide first, to help people at the bottom?
I narrowly missed (because they changed the day) taking part in the evacuation exercise which was part of the certification process for Braniff to operate Concorde. Never flew the SSC but I nearly got the chance to jump out of it. Despite it not being for real, there were several injuries at the bottom of the slide.
14th Jun 2012, 00:26
does one of the CC go down the slide first, to help people at the bottom?
Depends on the airline. I work for a Qantas regional flying Dash-8's. First out in an evacuation is the FO.
15th Jun 2012, 20:04
I think my intentions have been miss-understood. The memory items end with the actual command to evacuate. The procedure performed is then backed up (confirmed?) by the actual checklist to make sure that nothing has been missed. LSM has it spot on when he says "with people ripping through it fast critical items were being missed. Consistently." From what I understand this is the manufacturer's procedure. We no longer use our "own" procedures.
21st Jun 2012, 23:57
I was involved with CC training some time back, but remember that the evac "procedure" begins when pax are being allocated seats. Stable-looking (?), fit, healthy, 'sensible' pax are often selected to sit in the emergency evac rows.
Here the process divides into 2 streams: 1. Fore-warned emergency events (non-lock of MLG for example), or 2. The "Oh Hell!" event.
For Stream 1, the occupants of the emergency exits mid cabin and/or, in some cases/aircraft/airlines, the rear exit, the nearest 1 or 2 pax is/are briefed on operating the exit and asked if they are reasonably confident in being able to operate it. I understand that some airlines do this on every flight as a matter of course - not a silly idea.
There are any number of variations, but if it's a pre-warnable event and the a/c is still in the air, pax are briefed by the Cabin Manager (or equivalent) on what to expect and what they must and must not do. If time permits, CC check individual seat groups to make sure instructions have been understood and to answer questions, as well as to assure and calm pax.
Just before landing, "Brace, brace brace" from the front office on the p/a, followed by "Head down, stay down" chant from CC.
Here, both streams become pretty much common but a lot relies on the size and configuration of the a/c and the number of CC.
Once a/c is stopped and flight deck checks completed, "Evacuate, evacuate, evacuate" from the flight deck if deemed necessary, doors opened, slides deployed if appropriate, followed by shouted commands from the CC - "Come this way/Get out/Jump"
Then there's the after-match function of herding the pax to a safe point, etc.
Even in training there can be unfortunate accidents/incidents, such as slide burns, injuries from 'pax' getting over-exuberant and the like. We even had one occasion where a deplaned pax tripped off the end of a safety mat and smacked herself into the concrete floor. She was unconscious for about 2 or 3 mins, so ambos were called to see to her while trainers did the First Aid thing.
Sorry this is so lengthy, but I hope from it you'll get the idea that there are so many variables that it's almost impossible to say "This will happen, then this, then that." Best advice I can give is read and understand the safety information card in the a/c you're on, listen to/watch the preflight cabin briefing and follow the crew's instructions if the excrement hit the windmill. This will give you the best chance possible of survival if "the worst" happens.