Due to multiple factors, the design of the rear left sliding door (emergency exit) on the EC120B helicopter was not simple and obvious to use unless the occupant was provided with specific instructions about how to operate the exit. In particular:
The ATSB acknowledges that, in this case, a complete change in door design is not a practical solution and that the introduction of enhanced placarding for the EC120B rear left sliding door via an alert service bulletin (ASB), coupled with a thorough pre-flight briefing, will reduce the risk of this safety issue.
Issue finalisation date: 20 June 2022
The Australian Transport Safety Bureau recommends that Airbus Helicopters takes safety action to address the safety issue associated with the design of the rear left sliding door on the EC120B helicopter to ensure that, as best as possible, the door is simple and obvious to use and/or passengers are provided with sufficient instructions so that it is simple and obvious to use.
Please be informed that Safety recommendation AO-2018- 026-SR-073 has been taken into consideration and this topic is presently under analysis within our continued Airworthiness process.
As a first step of this analysis Airbus Helicopters has decided to initiate a Human Factor Analysis to assess the different aspect of the door opening including the marking but also the door operation itself. This analysis is in progress with the purpose to observe the behavior of each participant involved in this Human Factor analysis when the order is given to evacuate the helicopter.
We will inform you of our conclusion of this analysis as soon as available.
The ATSB will monitor the progress of Airbus Helicopters' analysis and review and assess the safety issue on completion.
Please be informed that the here above Safety recommendation AO-2018- 026-SR-073 has been taken into consideration and this topic has been analysed within our continued Airworthiness process.
As a first step of this analysis Airbus Helicopters has initiated a Human Factor Analysis to assess the different aspect of the door opening including the marking but also the door operation itself.
Two groups of population have been observed, without experience or background on helicopters: 10 participants received a pre-flight briefing and 10 participants do not receive any information. All participants did not know the reason and objective of this observation.
The goal was to observe the behavior when the order was given to evacuate the helicopter.
Some parameters were measured:
- Reaction time (including the duration taken to identify the actions to be conducted to exit the vehicle) ;
- Duration to perform physically the exit maneuver ;
- Perception (evacuation, effort, usability and understanding of markings).
The results of this analysis, from a Human Factors perspective showed:
- That the majority of the population manage to open the door in less than 8 seconds (in a moderate level of stress situation).
- Nevertheless the manoeuver was not obvious for 2 persons and the current markings do not help to ease the understanding of the users.
Based on this analysis and the result obtained Airbus Helicopters decided to focus on handle and marking as the most appropriate and adequate potential improvements.
- Introducing a new wording requesting to push out the door after having pulled up the handle (Additional instruction label)
- Making the door handle readily apparent (New label),
- Indicating the “Push” location on the door (handle label)
These additional markings provide the sufficient instructions for a simple and obvious use of the door.
These decided modifications are presently in the certification process and as soon as available an Alert Service Bulletin will be issued to mandate their application (this ASB will integrate the new marking and how to apply it). We will keep you inform as soon as these Alert Service Bulletin will be available.
The ATSB acknowledges the analysis work conducted by Airbus Helicopters to further examine this safety issue. The ATSB also acknowledges that the introduction of enhanced placarding for the EC120B rear left sliding door will reduce the risk of this safety issue. Therefore the safety recommendation is closed.
