This rulemaking task concerns the update of CS-27 and CS-29 with regard to helicopter ditching requirements.
Water impact events involving helicopters — even when ditching is successful — may still result in fatalities due to the difficulties of escaping from a flooded and inverted cabin. Disorientation, rapid flooding and cold-water conditions can prolong evacuation beyond occupants’ breath-hold capacity, with drowning remaining the most common cause of death.
Previous EASA rulemaking activities (RMT.0120 , NPAs 2016-01 and 2020-16) introduced substantial safety improvements but did not adopt the proposed air-pocket post-capsize survivability feature because of concerns over technical feasibility and potential hazards, such as the inadvertent deployment of high-mounted flotation devices near the rotor system.
Furthermore, recent research (EASA.2019.HVP.18 ‘Flotation Systems’) has addressed these concerns by demonstrating the feasibility of high-mounted flotation units, which can keep part of the fuselage above the waterline after capsize and provide a breathable air pocket for occupants until escape is possible.
In this context, the objective of this rulemaking task is to propose enhancements to rotorcraft design standards to further improve the ability of occupants to escape from the cabin and survive in case of helicopter ditching.
To this end, this rulemaking task proposes to introduce the air-pocket concept as an optional design feature in CS-27 and CS-29, and in the relevant acceptable means of compliance.