Emergency descent : Question for ATC
 

Hi ATC

Please can somene confirm what ATC expect us to do in European airspace if we have to make an emergency descent ? I'm hearing conflicting info that in Europe we stay on the airway but ICAO doc states we turn off the airway ( direction at crew discretion.)
Please can someone clarify ?

Thanks very much.

In Belgium, we expect you to turn away from the assigned route or track before commencing descent.

However, we won't be mad at you for descending straight ahead. But please inform us asap if you do so. A simple 7700 will do...

Turning off the airway is not really an option in large chunks of airspace such as spine of U.K. If you gotta go down you gotta go down. Just tell ATC with 7700 and a MAYDAY call. I've been involved in a couple and seeing a B767 making an emergency decent from FL310 is not something I will ever forget:\

Emerg descent - consider clearing the airway 90 L or R of track for 2 mins then fly parallel to the airway.

In reality if you stay on the airway you have more chance to inflict traffic below, whereas leaving the airway would reduce the likelihood.

For the UK:

http://www.ead.eurocontrol.int/pamsl..._2012_P_138_en

Or if the link doesn't work it's AIC Pink 138/2012.

The following info is for central Europe- it is not relevant out side radar coverage and under procedural (oceanic) control.

Over most of Europe it will make no difference whether you turn or not. 80% or ac will on directs or if not you turn into another airway. Follow the company book to cover your ass but be aware turning will not make a scrap of difference in reality

If it is real bad just put 7700 in the box and do what you have to do. we will quickly work it out ;)

If not so bad 7700 and a mayday call- we will clear the way for you- but you have to give us the chance.

Also you must consider that once you descend you can be entering another FIR. We have to call them and tell them- they will see you coming if the 7700 is on. If you don't have 7700- the first they might know about you if the short term conflict alarm with their traffic.

Feel free to PM if you want any more info :)

Oceanic have their own rules, deviate 15 miles and descend (tracks are at least 60nm apart). If you are on a direct routing it makes bugger all difference, every country and airspace is different so only answer is check the relevant AIP. Most important thing as was said earlier is the squawk. There are filters on the radar system to stop flights showing on your screen that are outside your sector I.E. If you are in charge of FL125 to FL235, you aren't going to want to see aircraft above that, so you can filter them out. When you squawk 7700 the filters are over-writtem, so everybody sees you and can prepare for a sudden descent by moving any potential conflicts, so the squawk can be more important than the Mayday in busy airspace

A quick look on the TCAS?

You my be interested to know that in my company, placing the transponder to 7700 TA comes before the Mayday in the memory items.

For those flying in Europe (as Jeppesen Route Manual says):

SPECIAL PROCEDURES FOR IN-FLIGHT CONTINGENCIES EUROPE
Ref Regional Supplementary Procedures ICAO DOC7030 - EUR

EMERGENCY DESCENT PROCEDURES

ACTION BY PILOT-IN-COMMAND

1. When an aircraft operated as a controlled flight experiences sudden decompression or a (similar) malfunction requiring an emergency descent, the aircraft shall, if able:
a. Initiate a turn away from the assigned route or track before commencing the emergency descent;
b. advise the appropriate air traffic control unit as soon as possible of the emergency descent;
c. Set transponder Code to 7700 and select the Emergency Mode on the automatic dependent surveillance / controller-pilot data link communications (ADS/CPDLC) system, if applicable;
d. turn on exterior lights;
e. watch for conflicting traffic both visually and by reference to ACAS (if equipped), and
f. coordinate its further intentions with the appropriate ATC unit.

2. The aircraft shall not descend below the lowest published minimum altitude which will provide a minimum vertical clearance of 300m (1000ft) or in designated mountainous terrain 600m (2000ft) above all obstacles located in the area specified.

The Jepp info is about right, but in Free Route Airspace turning away could be more dangerous than continuing straight ahead

I would like to add the importance of the 7700 squawk. That, more than anything gets every controller's head up whether you're working that sector or not.

I remember one time working a BA diversion into Manchester that made a rapid descent due to a cracked cockpit window. My filters are usually set around FL245, and it was above FL310 from what I recall. As soon as the 7700 came on I could see it on the radar and seeing the altitude drop was the first I knew it was likely coming my way. Gave me chance to get a few aircraft out the way before I got the call from the sector above telling me it was coming.