# Decompression Procedures

> Handling cabin decompression and emergency descent.

- **Subject:** 070 — Operational Procedures
- **Section:** 071-02 — Special Operational Procedures and Hazards (General Aspects)
- **Topic code:** 071-02-06
- **Last reviewed:** 2026-04-01
- **Author:** Pablo Asensio Martínez
- **HTML version:** https://pilotsyllabus.com/en/operational-procedures/special-operational-procedures-and-hazards-general-aspects/decompression-of-pressurised-cabin/

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## Types of Decompression
*   **Explosive**: Very fast (< 1 sec). Lungs can be damaged due to expanding air. Fog in cabin (adiabatic cooling).
*   **Rapid**: Fast but lungs can vent.
*   **Slow**: Gradual loss. Dangerous because it may go unnoticed (insiduous hypoxia).

## Immediate Actions (Memory Items)

![Passenger oxygen mask](https://upload.wikimedia.org/wikipedia/commons/f/fb/Passenger_oxygen_mask_dsc06035.jpg)

1.  **Oxygen Masks**: ON and 100% (Emergency).
2.  **Communications**: Establish between flight crew.
3.  **Descent**: Initiate Emergency Descent if cabin altitude exceeds 10,000 ft (or structural damage suspected).
    *   Turn off airway (usually 30-45 degrees).
    *   Speed Brakes: Extend.
    *   Thrust: Idle.
    *   Target Altitude: 10,000 ft or MSA (whichever is higher).

## Post-Descent
*   Check for structural damage.
*   Assess fuel endurance (higher consumption at low altitude).
*   Check passengers for hypoxia/injuries.

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Free study notes from pilotsyllabus.com. Not a substitute for training at an approved ATO.