Emergency Descent Procedures??

[Captain Slack Bladder]

Hello Ladies and Gents. I wonder if you could advise what you expect an aircraft to do in the event of an unannounced emergency descent. Let's assume it's an explosive decompression and the crew are busy with checklists/donning O2/dust flying around/fog on the flight deck etc etc. The main reason I ask is that I'm a simulator instructor and cannot find the definitive answer. It may well vary from State to State. Thanks for your input!!

[Bagheera]

Captain Slack,
if a call is at all possible then get one out...just callsign and explosive decompression would suffice...we would then be expecting to see you in a very rapid descent to round about FL100...when able squawk 7700...For our part we will be getting everything in the vicinity as far from you as possible and, in the case of split level sectors, coordinating with our colleagues...no need for you to talk again until level and letting us know your further intentions

[Bagheera]

captain Slack,
a colleague,actually my wife, has said that an experienced controller who trained her suggested once the aircraft was level that a number of seemingly irrelevant questions could be asked...ie whats your aircraft type/registration etc..to determine whether there was any after effects of hypoxia

[Cornish Jack]

Bagheera
Just a further query - what about the
(90 right/90 left) turn to clear contolled airspace? Is that no longer a requirement?

[Capt Pit Bull]

Bagheera,

Is that really such a good idea?

Without wishing to appear ungrateful, in a serious emergency situation the last thing we need is ATC calling us unless it is a direct immediate necessity (e.g. you have terrain in front of you, climb now).

I appreciate that you said wait until the aircraft has levelled off, but even so the odds are that PNF (the guy doing the radio) is up to his armpits in checklists.

We are unlikely to be suffering from hypoxia at that stage: - we will be masked until we are sure the cabin is at a safe altitude, and recovery from hypoxia is very rapid once the partial pressure of O2 goes back up (unless you're dead).

Even if you were to deduce that we were suffering the after effects of hypoxia, what could you do about it? With the exception of a single pilot aircraft (who perhaps you might be able to coax putting a mask on) there are others near by (in the other seat, or the cabin crew) who are specifically trained to cross monitor one another.

If I could just explain a bit about what we are doing when we are running a checklist. I can't speak for the ECAM boys, but in our aircraft it is a spiral bound document, and many of the checklist items require reference to other pages to determine ops data or check bus equipment lists. In other words its a minefield, and you dearly want to not be interupted. Typically, I have got one hand on the checklist, with one or more fingers wedged into it to 'bookmark' procedures that we are running, and a finger running down the page in use to keep track of where we are in the checklist. That leaves me with one hand to do everything else, including actioning the checklist items, making any AP/FD/Navaid selections (if the aeroplane is very sick, the other guy is probably hand flying), pressing the PTT, and anything else that needs doing. So any call that you make interupts the process, which rapidly increases the probability of items getting missed or actioned in error. If you call me with something I need to write down, then I'm in danger of running out of hands. God help me if I put the checklist down, because it will take me 10 or 20 seconds to find my place again!

In summary, what we would like , in the event of an emergency (descent, or otherwise)is for ATC to get everyone out of our way, and just wait for a minute or two until we have had a chance to run our checks and assess our situation. I know that it is in everyone nature to want to help as much as possible, I totally respect and appreciate that, but sometime silence is golden. If time is really critical, and we need an immediate vector for landing, we'll ask for it.

What I try to do (in the sim - thus far I've had no really serious problems when airborne) is as follows: Working on the assumption I might need to divert to XYZ, I call ATC and request them to get its weather, and to standby until we say we are ready to copy it. This is something directly useful for us that ATC can do without interupting us.

I hope that gives some insight into our workload. To reiterate, we do appreciate greatly all ATCs efforts during emergency / urgency situations, but you can have too much of a good thing!

Regards,

CPB

[need to know]

Do airlines have the same SOP for emergency descents or do procedures vary from company to company? The idea of an aircraft pointing the nose down for a lower level at the fastest possible rate without any kind of a call scares the **** out of me. Traffic can be so tightly packed at times, it would be great flying to miss everyone around you. Don't get me wrong, I appreciate in that situation calling ATC is the last thing on your mind, but what happens if your on the North Atlantic flying on top of the track with every level below you blocked or flying along a busy airway? Is it a SOP to off-set during emergency descents or is it just nose down and hope ATC gets everyone out of the way in time?
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And that's what I think about that.

[This message has been edited by need to know (edited 08 June 2000).]

[jjj]

What if you are outside radar coverage and I can't move the traffic. Do you want traffic information on traffic which is conflicting with you? Or should I just tell the traffic that you are conflicting with you are on emergency descent.

[Numpo-Nigit]

As those before have said - a really scary situation in a busy environment. Obviously, any indication you can give ATC as to what you're doing and why is a great help, but I equally understand that's often impossible. Without any clues, it just means we have to assume the worst-case and try to get everybody out of your way. Of course we will call you, if only to reassure ourselves that the rapid descent is intentional and not the result of some mid-air catastrophe, but we don't expect to always get a coherent response. There are no rules as to how you go about things, as every airborne emergency is different - basically just do what you think has to be done to minimise risk to yourself and your passengers. We do practice scenarios like this in our annual "Emergency Training" day, but the real thing is something else! Amazingly, the two that I've observed over the last twelve months have descended right into the heart of the London TMA finding a clear space both times - long may that sort of luck continue!!!

[identnospeed]

Agree with Bagheera, in an emergency descent situation, I would expect callsign and "emergency descent" or similar, nothing more. The traffic underneath you would be moved out of the way. However, without the call, you have a good chance of hitting something.....a chance which increases by 7% a year !!

I believe the BAC1-11 pilot in the June 1990 incident over Cowly started his descent at about FL180 and got a call in within a couple of thousand feet.

INS

[10W]

I would expect pilots to Aviate, Navigate and Communicate in that order. Not ideal for me sitting watching it all on radar and not knowing what is going on but as has been said, my first task would be to get everything out of the way and try to provide whatever assistance I could once the pilot is ready.

I'd recommend setting 7700 as soon as possible especially if you don't have time to talk. Not only does it alert me but other controllers can also be aware very quickly of a potential problem. It may be the thing that is the difference between someone getting traffic out from underneath you or you having a mid air, God forbid. Remember that the responsibility for preventing collisions is no longer the controller's responsibility if you're in this sort of scenario...it becomes yours until ATC are back in the loop with you and provide a safe reclearance, in other words an extra workload which is an unwelcome addition to that imposed by flying the aircraft safely and running the checklist.

Oceanic aircraft have specific procedures including off sets from the aircraft route.

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10 West
UK ATC'er
[email protected]

[Grandad Flyer]

I would have thought if you weren't under radar then it would probably be safer to turn off the airway a bit.
However, I believe in most situations that you can pause momentarily, once the masks are on, to call ATC with callsign and "emergency descent" and add "request heading". ATC only have to make one call back to acknowledge and give a heading and level cleared to (assuming FL100 or MSA) but if they were to also say "heading XXX, FL120" (or whatever), due to something in the way, I could cope with that.
How long has been wasted? A few seconds? Then we start down and turn onto heading if required knowing we are safe from other traffic.
We have enough oxygen on board to allow this to happen, and if spending a few seconds, hell, even 30 seconds, to get a heading such that we avoid descending on someone/ mid-air, then I think it would be worth it.

[need to know]

Well said Grandad. A few seconds to make a call and receive a steer clear of traffic from ATC may save an episope of Black Box about our efforts. It's probably the last thing on your mind in such a situation but without it, it might be the last thing on your mind!!!!!!!!!!!

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And that's what I think about that.

[Bagheera]

To Cornish Jack and Capt Pitbull,
Just a follow up....jack although the turn left/right 30 degrees and leave is still recorded..I think i am right in saying nobody would actually expect it and to be honest in crowded airspace like Daventry or Clacton could actually cause more problems.....Pitbull on further disussion with the boss! she says that what her mentor was saying was that once the aircraft was stable again ,these questions could be asked not to try and influence decision making but to determine the speed of communication henceforth ie headings,speeds..length of final approach that may be needed etc.

[Bagheera]

Capt Pit Bull,
having re-read your reply...I now realise that you are saying you will influence the speed of communication...Im more than happy with that...never liked the wifes mentor anyway!!!!Although this situation yet again proves the value of PPRune, as I am now an approach controller its never likely to arise for me....unless youre really high on the slope!

[Capt Pit Bull]

Ah.

I realise my post may not have been clear.

I was referring to Bagheeras second post (about asking questions like registration etc), not the earlier post about getting a call out about an emergency descent.

In an emergency descent scenario I'd say something like "Callsign, Emergency decent to FL 100 turning right heading 050, advise if unsuitable."

I'd expect ATC to acknowledge (and ammend if my flight path was unsafe).

JJJ. After the level off, (or in any general emergency scenario) I'd like you to tell me if I'm going to lose safe separation against anything that you can't move out of my way, be it Terrain, Aircraft you're not controlling, active danger area or whatever.

We'll get ourselves sorted ASAP and advise you of our plan / request any div info we need. If its a time critical problem, advising you of the fact will be very high on our priority list.

CPB

[karrank]

Just go and trust to the big-sky theory!

I would (off-radar) pass traffic to others affected. A suggested heading for anybody (except in a hold) is as likely to fine-tune a collision course as fix the situation.

I would not expect much in the way of information initially ("Yuppie6942 on emergency descent"), but once I had completed my immediate actions (traffic, broadcast, separation where possible, declare emergency, put down magazine, coordination) I would prompt for more information from the crew "when able".

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"Cut him off and call him shorty!" - Lorenna Bobbit (Patron Saint of ATC)
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[Big Nose1]

As always there is no straight answer to this situation. After discussion with others at LATCC I think that turning left or right would achieve little.....with so many air routes, aircraft on radar headings, complex airspace there is no guarantee that a turn would keep you clear of traffic. As I have experienced two decompressions it is very difficult to understand what pilots are saying in the initial stages so I would rather you continued your current heading than changed left or right without my knowledge, either intentionally or thru difficult RT.
I think pilots no.1 priority should be squawk A7700, then call mayday if you can. The main reason being that we have increasingly vertically sectorised airspace and the Controller you are talking to may only have responsibility for airspace 280 and above. Obviously you require to descend to 100 or there abouts and may have to descend thru 3 or 4 different sectors. We of course telephone other sectors as you are on your way down, but this can be time consuming, if you are squawking 7700 your label is forced thru to other sectors and they may already be moving traffic out your way by the time a phone call is made, saving potentialy vital seconds in clearing a path. other advantages of 7700 are showing other units, airfieds, military controllers and the D & D cell of a problem.
I would always try to leave any RT tx to you until I`d seen you level at 100, but I would want to speak very soon after that. The main reason being to transfer you to a discreet frequency, with a dedicated controller, this is SOP at LATCC. My frequency will become extremely busy with constant RT while we recover the carnage around you and we think a nice quiet freq is more conducive to completeing check lists etc .

[Captain Slack Bladder]

Thanks very much for all your input. It's a bit like I thought, lots of different expectations. 7700 seems to be popular and has cleared up one theory which ran along the lines that you should not set 7700 if you are already in comms with an ATC unit!!
On the NAT tracks our SOP is to go left or right 90 and then start down. If we are going West on Track A then obviously a right turn would apply. Thanks again.
PS I put the wrong Smilie in by accident and don't know how to change it!!

[This message has been edited by Captain Slack Bladder (edited 10 June 2000).]

[V1 Rotate]

We were drilled to don masks,pilot flying to turn left 90deg. off the airway speed brakes, nose down. Pilot not flying select 7700, set alt preselect, check pax O2......

V1 Rotate.

[APP Radar]

One ATCo point of view.
I would expect to see 7700 and ear "XXX emergency descent".

My first concern would, then, be issue a general traffic information stating your position, heading and the level you're clearing to the aircrafts on the same area.
If possible suggest a right or left turn for the descent otherwise vectoring other traffic out of your way.

If the flight is on a non-radar area, a left or right turn to leave the airway could be a good idea but sometimes it's not enough because even on non-radar airspace there are "direct to" clearances.

On a radar coverage area I wouldn't expect anything else ...

[shakespeare]

The Jeppesen appears pretty clear about emergency descent procedures. Announce "emergency descent" in the phraseology section and squawk "7700" in the emergency section.

It would be great if ATC could issue a "preferred procedures" outline as a guide to this procedure. Turning off the airway and waiting to tell ATC are very valid points but a little discussion would go along way I believe.

[Raymond_V]

I'd expect and prefer the "emergency descent" call, 7700 and ADS emergency selection if appropriate. Also we've been trained in OZ to expect the 90 left or right turn, direction dependant on the air route configuration.

We'd pass traffic to whom ever else might be in the way and begin alerting everyone affected. I agree the 7700 makes this latter process easier and quicker.

Obviously we'd be keen to hear from you as soon as you're able.