Emergency Descent.

[britannia66]

Information please .... in the UK would ATC like 7700 on the transponder in an emergency descent, or should the existing code remain set. Also, what is the logic behind the answer? Thanks. :ugh::ugh::ugh:

[Ben-B]

Emergency descent would be a mayday situation wouldn't it?

Don't they usually keep you on the same squawk if you're already in contact with them?

Would have thought it'd be easier to make a mayday call and ident than input the 77

[5milesbaby]

Been covered lots on here.

Personally, I'd want 7700 selected ASAP. Too many closely packed/vertical sectors and possibly lack of RTF contact means it can save a situation getting worse. Can only think of a few sectors down SWwards of the UK airspace structure that actually control from CAS base to FL660, everywhere else is vertically split, most even shared between 2 different rooms, not forgetting different centres....

Also, contrary to Europe I believe, continue present track, don't turn 30 degrees off route, never good in the UK.

5mb

Edited to add:
It used to be a case where by selecting 7700 lost the identity of the track data block to the controller, but in NATS at least, this no longer occurs, we still retain the full identity and also have a further indication that you are also squalking MAYDAY. In Swanwick AC this appears with "SOS" above your data block and also has a flashing red and yellow box around the data block.

[slatch]

In the US the same applies, the data block stays associated to the target symbol when squaking emg. I would squak emg ASAP because it overides filter limits and settings. Everyone sees it. In the case were you are handed off to another sector or ACC but have not entered the airspace it gives the controller some warning while he waits for the phone call from the sector in communication. Also the Mode C logic is suppossed to be overidden and actual altitude reports shown without logic check. However, as of a year ago I can say this is not always true in the US.

[Lon More]

Callsign correlation remains in most systems now, also displayed in an accentuated form (colour or brightness). As stated, very nice when entering another controllers airspace where there is a possibility that the flight was not even displayed previously.
Some years ago the possibility of the flight data being displayed through RADNET, even if at a different unit, was being investigated at Bretigny IIRC. Don't know what became of it.

[phantomlurker]

Hi
As I understand it, setting 7700 (or 7500/7600) automatically shows up on the radar display regardless of which filters may have been set. This allows controllers in adjacent sectors (either laterally or vertically) to be aware and to plan accordingly.
This is in reference to NATS btw.

pl

[divingduck]

The setting of the Emergency codes will burn through all filters in the Irish airspace too. Very handy if there is a super/upper/low/overhead a tower split happening at the time

[Gulfstreamaviator]

Left turn 90 degrees, and descend fully auto at Max speed to 15,000 ft.

Not certain how it guesses 15,000 ft, as where does QNH come from.????

Being an american aircraft, I am assuming thay below 180 it must be QNH.

To expedite the descent the speed brakes are manually extended.

The system could, and in my opinion set 7700, but does not.

glf

[5milesbaby]

Gulfstreamaviator, if flying in UK airspace I would highly recommend you override the "left turn 90 degrees" and actually just continue present heading, much much safer.......

[Pontius's Copilot]

Gents, I draw your attention to the following -

UK Aeronautical Information Circular, AIC: P 052/2009, 'Emergency Descents in UK Controlled Airspace'. It states

2.4 Turning-off or Remaining on Track in UK Controlled Airspace

2.4.1 UK Controlled Airspace is complex and congested; traffic is often oriented on the airway in certain directions or flows. Therefore, if able,pilots should remain on the assigned route or track whilst carrying out the emergency descent; unless to do so otherwise would endanger the aircraft. Notification of this preferred action in UK Controlled Airspace shall be published in the UK AIP GEN section under PANS-ATM paragraph 15.1.4 - Emergency Descent.

2.4.2 If a turn away from an assigned route or track is initiated, pilots should note that they may not be aware of traffic in their proximity (especially if flying on an assigned heading): nor of aircraft below them, not on the selected frequency, in adjacent airspace sectors. However, it is ultimately the pilot’s responsibility to take the action most appropriate in the circumstances.

[cambridge]

Definitely 7700. See AIC P 052/2009. It "burns" through all ATC filters. :)