Emergency Descent in the UK
 

The UK CAA has recently written to (emailed) UK TREs seeking opinions as follows:It may well be that some of you have also been asked already - I'll be surprised if NATS isn't seeking the same, but I wonder what the broader view (range of opinion!) is.
As a supplementary question for discussion, should the descent prescribe (or preclude) a turn away from current track (or route centreline)?

As an ATCO, I would want a 7700 squawk ASAP, especially in an emergency descent. I would also like it for all other emergencies that require me to give an a/c priority.

It's not just the aircrews workload that increses during an emergency - an ATCOs does as well. Squawking 7700 tells everyone else around to get out of your way and thus helps reduce some of the workload.

I don't see any reason why 7700 cannot be selected at or near outset of an emergency the majority of times, including emergency descent (apart from maybe an explosive decompression). It can be done immediately after the 'immediate actions', i.e. at the time that you should be transmitting your call to ATC.

The words 'emergency descent' make the manoeuvre sound more punchy than it actually is - it should still be a very controlled manoeuvre, albeit slightly uncomfortable when you put the masks on etc.

I think that ATC should prompt 7700 and that it should be included on the check list for the pilot, it is a very efficient way of letting everyone know what is going on.

In the UK due to the way the airspace is structured with multiple sectors sitting on top of each other, lots of the those sectors will have height filters on. A 7700 will break through those filters and alert the underlying sectors before the initial sector can tell them themselves, this means any conflicting traffic can be moved out of the way in good time.

As for a turn of the airway, i don't think it is a good idea. If we know what the emergency aircraft is going to do ie fly straight ahead, then we can help more by getting the right aircraft out of the way instead of trying to predict what is going to happen.

Do aircrew have to select 7700 manually, or like some mil jets is there an emerg button that they can press to override the squawk in the box with 7700??

if not could this bit be retrofitted (obviously expense will be the limiting factor). It just seems that it would be something that could increase the speed of response to an instruction and wouldn't detract from the ermergency checklists.

Just a thought :eek:

Fly straight ahead
 

Interesting that you should say that, in the case of a decompression my aircraft automatically turns 90 degrees off track and initiates its own descent to fl150 as soon as I close the throttles and deploy speedbrake.

Its actually very difficult to override it without disengaging the autopilot!

Blimey G-SPOTs, what do you do if the MSA on your left is 18000ft and the aircraft insists on turning that way? I guess you disconnect the AP and revert to two parallel single-pilot cockpits then.

It seems to me (and I've heard it from many controllers) that in today's multiple parallel-track environment, any turn could cause real problems for ATC - at least if the default is no-turns then they know which direction you're going to go in the immediate future.

On the subject of 7700, I'm sure most operators specify setting 7700 in the ECL as either a Memory Action or a Subsequent Action in the Drill. But obviously not everyone does it or the Authority wouldn't be asking.

In the charter company I work for it is part of the memory drill to set 7700 and to press heading select to maintain heading for the rapid decompression drill.

What sort of aircraft are you flying, G-SPOT?

Slight thread drift.....
I remember working in PATCRU in the early '70s when a RN Devon, 25nm NW Wal on the old R3 called "Mayday, Mayday, double engine failure", and the Procedural ATCO [at PATCC] replied with...."Roger Navy123, maintain F80"........:hmm:

Preston Air Traffic Control Radar Unit was on the first floor of the Tower Block at Manchester Airport......
Preston Air Traffic Control Centre was at Barton Hall, near Preston....
Oh how things have changed.....
watp,iktch

Interesting to read the above.

My (UK long-haul) company policy is to maintain present squawk "if in contact with ATC", unless ATC asks us to change it.

Regarding heading change - no company policy that I know of, but the general feeling is to maintain present heading if in radar coverage. If we do have to change heading for some operational reason, then make it clear to ATC what we're doing. Outside radar coverage, turn away from the airway centerline.

Hope this helps,
t

I might be barking up the wrong tree here, BUT, I do recall somebody mentioning to me a requirement in the ANO to turn off present heading/track when starting and emerg. descent?

L Met

PS

Re 7700 it is in our company SOPA's for the PNF to set 7700.

Something for the pilots to think about...
Something that's left out of many Emergency descent drills is lights on.

Personally I would prefer it if the pilot selected 7700 as a matter of course if a MAYDAY scenario ocurrs. I'M only going to tell him to do it anyway.

PAN's or any other situation and I'LL make the 7700 decision.

Spamcan