FOCA SAND 2019-002
The issue
In February 2019 the following incident occurred at Geneva airport:
The air-conditioning system (preconditioned air PCA) was connected to an Airbus A320 for the overnight stop. The PCA was put into operation with the doors and the outflow valve closed. As a result, there was excess pressure in the cabin the next morning. The consequence of this was that the doors of the A320 opened explosively when they were operated by the crew. One person was slightly injured and the passenger bridge was damaged.
Apart from the recent event in Geneva, other incidents and accidents are known internationally in which injuries and even fatalities occurred, inside or outside the aircraft, as a result of the explosive opening of cabin doors. For example, an occurrence in Finland in January 2018 caused the death of a crew member who died at the scene of the accident as a result of an explosive door opening.
Flight crew, ground handling personnel and maintenance personnel are at risk.
Cause
The main cause of these incidents lies in the unintentional development of an excessive pressure differential inside and outside the aircraft. Such a difference in pressure can develop if the air-conditioning system is powered by the APU or another external source when all the aircraft's doors as well as the outflow valve are closed.
Measures
In order to prevent such excess pressure from developing, specific procedures - depending on the aircraft type - must be complied with. These procedures must be communicated and trained for regularly. Also, crew and ground handling personnel must be aware of the signs of a possible excess pressure inside the aircraft:
• All aircraft doors and windows as well as the outflow valve are closed
• The APU or another external source is running / is connected
• The aircraft doors can be opened only with exceptional difficulty
• Physical indications within the aircraft (pressure in the ears, in the chest)
EASA safety information bulletin
In February 2019, the European Aviation Safety Agency (EASA) published Safety Information Bulletin 2019-2 “Explosive Door Openings on Parked Aeroplanes, SIB 2019-2” concerning this problem. The bulletin explained the nature of the problem and made recommendations to aviation companies, training organisations, maintenance companies and aerodromes:
EASA SIB 2019-2: https://ad.easa.europa.eu/ad/2019-02
Other sources
• Investigation Report L2018-01 on the accident at Kittilä Airport (Finland) on 4 January 2018
