Rapid Depressurisation/Decompression

Definition

Decompression which occurs rapidly but at a rate which is less than the rate by which the lungs can decompress and, therefore, does not result in damage to the lungs.

Discussion

A rapid depressurisation event is more common than Explosive Depressurisation and is usually associated with larger aircraft. Depressurisation occurs in a matter of seconds at a rate greater than 7,000 ft/min, and is normally associated with a ‘bang’ and a sudden fogging of the cabin air.

The greatest danger of depressurisation is crew incapacitation due to Hypoxia. The Time of Useful Consciousness will be reduced proportionally to the speed of the decompression. Decompression Sickness is another potential hazard associated with high altitude decompression.

If the cause of the decompression is a structural failure, failure of a window for example, there may be a risk of some crew or passengers being buffeted by strong winds, hit by debris, and extreme cold temperatures, or even of being sucked out of the aircraft - another reason for wearing a seat belt or harness whenever seated.

Related Articles

• Loss of Cabin Pressurisation
• Explosive Depressurisation
• Gradual Depressurisation
• Aircraft Pressurisation Systems
• Aircraft Oxygen Systems

Further Reading

• See FAA "Lessons Learned from Transport Airplane Accidents": Pressurization / Decompression Failures

• ATSB Report: Aircraft Depressurisation - Cabin crew information bulletin

• AIRBUS: Flight Operations Briefing Note - Cabin Decompression Awareness