Safety investigation completed on a fatal business jet door accident which happened at Kittilä Airport on 4 January 2018 – international safety recommendations issued for preventing similar accidents
A fatal accident occurred during the departure preparations of a business jet on 4 January 2018. The build-up of excessive pressure inside the cabin resulted in the door blowing open with explosive force when the captain opened the door. The weight of the door and the pressure impact hit the captain and knocked him to the ground. The pressure wave also knocked the co-pilot, standing close to the door, down. The captain who received a heavy blow from the door died at the scene.
The fact that a fire extinguisher and a crash axe which were fastened to the cockpit’s aft bulkhead came loose from their fastenings and were ejected out approximately 5 m from the door demonstrates the force with which the door opened.
International safety recommendations for preventing similar accidents and safety improvements
The Safety Investigation Authority, Finland recommends that the Civil Aviation Authority of Israel (CAAI) supervise that Israel Aviation Industries (IAI) updates the operating manuals of the Gulfstream G150 and other comparable aircraft types. The updates should include a caution to check that the outflow valve is fully open before the door is closed. The cautions in the updates should be included in sections that address closing the door as a means of heating or cooling the aircraft.
Gulfstream G150’s Cold Weather Operations Manual states in many places that heating can be expedited by closing the door. In the manual’s supplementary checklist there is an instruction to check that the outflow valve is fully open when the APU is being used.
The Safety Investigation Authority also recommends that the European Aviation Safety Agency (EASA) inform air operators, ground handling organisations and aerodrome rescue and firefighting organisations of a safety threat which may be caused by aircraft pressurisation on the ground and consequent explosive door openings. The bulletin must include the actions with which the safety threat can be controlled, as well as a reminder to provide the associated training to all persons involved with handling aircraft on the ground.
In 2009 the EASA published “Study on CS-25 Cabin Safety Requirements", which it had commissioned. It charted the safety threats for cabin safety. One safety threat which was mentioned in the study involved explosive door openings when the cabin was partially pressurised on the ground. The study’s conclusions and recommendations state that explosive door openings have resulted in fatal and serious injuries which could have been prevented by better procedures or communication. The safety issue is relevant for all aviation professions involved with handling aircraft on the ground.
Owing to the international character of aviation, representatives of several countries and organisations participated in the safety investigation, which was led by the Safety Investigation Authority, Finland. Under Section 12 of the Safety Investigation Act, the Safety Investigation Authority decided that the designated representatives and advisers could participate in the investigation. The Ministry of Transport and Road Safety of Israel, the US National Transportation Safety Board Organization (NTSB) as well as the Austrian (SUB) and the German (BFU) air accident investigation authorities designated their accredited representatives to the investigation in accordance with the Convention on International Civil Aviation. In addition, under the EU Regulation on the investigation and prevention of accidents and incidents in civil aviation, the European Aviation Safety Agency (EASA) designated a technical adviser to the investigation.
The data from the Cockpit Voice Recorder and the Flight Data Recorder were downloaded in Germany at the BFU’s laboratory. The Cabin Pressure Control System unit was sent to the NSTB, under whose supervision it was analysed.
Ismo Aaltonen, Chief Air Safety Investigator, tel. +358 295 150 703
Veli-Pekka Nurmi, Executive Director, tel. +358 295 150 701