GM1 SERA.11001 General

CAA ORS9 Decision No. 11

EMERGENCY DESCENT PROCEDURES

(a) When an aircraft operated as a controlled flight experiences sudden decompression or a malfunction requiring an emergency descent, the aircraft should, if able:

(1) remain on the assigned route or track whilst carrying out the emergency descent unless doing so would endanger the aircraft, in which case navigate as deemed appropriate by the pilot;

(2) advise the appropriate ATC unit as soon as possible of the emergency descent and, if able, intentions;

(3) set transponder to Code 7700 and, if applicable, select the appropriate emergency mode on the automatic dependent surveillance/controller–pilot data link communications (ADS/CPDLC) system;

(4) turn on aircraft exterior lights;

(5) watch for conflicting traffic both visually and by reference to airborne collision avoidance system (ACAS) (if equipped); and

(6) coordinate its further intentions with the appropriate ATC unit.

(b) The aircraft is not to descend below the lowest published minimum altitude that will provide a minimum vertical clearance of 300 m (1 000 ft) or, in designated mountainous terrain, of 600 m (2 000 ft) above all obstacles located in the area specified.

(c) Immediately upon recognising that an emergency descent is in progress, ATC units are to acknowledge the emergency on radiotelephony.

In particular, when recognising that an emergency descent is in progress, ATC may, as required by the situation:

(1) suggest a heading to be flown, if able, by the aircraft carrying out the emergency descent in order to achieve separation from other aircraft concerned;

(2) state the minimum altitude for the area of operation, only if the level-off altitude stated by the pilot is below such minimum altitude, together with the applicable QNH altimeter setting;

(3) as soon as possible, provide separation from conflicting traffic, or issue essential traffic information, as appropriate; and

(4) inform any other ATS units which may be affected by the emergency descent.

When deemed necessary, ATC will broadcast an emergency message, or cause such message to be broadcast, to other aircraft concerned to warn them of the emergency descent.

(d) Pilots receiving an emergency descent broadcast on the ATC frequency should:

(1) maintain radio silence on the frequency in use and listen for any further instructions from ATC; and

(2) watch for conflicting traffic both visually and by reference to ACAS (if equipped), and respond, as appropriate, to ACAS advisories.