CABIN PRESSURE AND OXYGEN DEFINE THE EMERGENCY-DESCENT PROBLEM
Distinguish aircraft altitude from cabin altitude and cabin rate. The emergency-descent source requires positive assessment of the excessive and uncontrollable cabin condition, followed by the applicable immediate response. Protect crew capability using the required oxygen equipment and communication arrangements while the flight path is established. A warning acknowledgement does not itself correct pressure, and a passenger announcement does not establish that oxygen has been delivered. Keep the crew supply, passenger system and pressure-control state as separate parts of the assessment. [21, PDF p. 265] [69, Pressurisation indications and controls] [79, Crew/passenger oxygen-system separation]
Choose the descent target with the applicable procedure, terrain and available safe altitude in view. A commonly remembered terminal level cannot be used everywhere without considering the terrain underneath and along the intended track. Confirm the route or heading strategy, ATC coordination when able, the active vertical mode and the actual descent. The FCTM describes the value of appropriate automation for reducing workload. Its sample rates, distances and heights illustrate that source's conditions; they are not guaranteed performance for every mass, speed, configuration or suspected-damage case. [21, PDF p. 265]
Speedbrake and speed choices must account for the actual aircraft condition. The source describes careful extension at high flight levels and additional care where structural damage is suspected. Reaching a desired descent rate is secondary to flying the applicable procedure within the remaining capability. Monitor speed margins and automation engagement during the manoeuvre, then complete the corresponding ECAM/QRH work once established as required. This chapter deliberately does not replace the aircraft's memory items with a shortened list of controls or a universal pitch/thrust setting. [21, PDF p. 265] [21, PDF pp. 65–70]
The subsequent landing assessment remains a separate task. Determine whether pressure control, oxygen availability, weather, fuel, remaining systems and the cause of the event allow a particular destination or require another suitable landing option. Brief the approach and coordinate the cabin using the actual situation. Fenix's Virtual Purser documentation describes a rapid-decompression announcement when included in the active pack. That cabin feature adds an observable response; its presence does not establish the full physiological, oxygen-endurance or emergency-procedure fidelity of the simulation. [21, PDF pp. 70–73] [81, Virtual Purser: Cabin Decompression]
Build the exercise from a stable flight with a named pressure fault and the applicable reference ready. Record cabin altitude/rate, differential pressure, aircraft altitude, terrain context, oxygen selections and achieved guidance. Identify which actions were performed as normal aircraft procedure and which were simulator controls used to set or end the exercise. On completion, restore the equipment and communication state through the appropriate procedure before another sector. A successful debrief explains how crew capability, flight path and subsequent landing plan were maintained, not simply how quickly the altitude decreased. [21, PDF p. 265] [127, Manual scenario controls]