Air New Zealand's "Skycouch" economy sleeper seats are to be made available to Airbus A350 and A330 operators under a licensing agreement.
The Star Alliance carrier is co-operating with UK-based SWS Certification Services to expand the seat's existing STC to cover the European widebodies as well as Boeing 777s and 787s.
SWS managing director Nigel Smith tells Flightglobal that approval on the A350 is targeted for July.
Air New Zealand developed a leg rest for its economy seats which folds up horizontally and – when extended in a row of three seats – forms a flat area that can accommodate two adults.
The airline has been offering a limited number of these seats on its long-haul fleet for five years.
Taiwan's China Airlines and Brazilian carrier Azul have adopted the retrofittable solution under licensing agreements, and Air New Zealand's head of aircraft programmes Kerry Reeves says contract discussions with additional carriers are under way too.
Reeves adds that the "Skycouch" has become particularly popular with families as it allows a parent to accommodate up to two children with more flexibility than if they were sitting on conventional seats.
Passengers must permanently wear loop belts that connect with the seats' regular safety belts. But Reeves says this set-up still allows passengers to move across the lie-down area, which makes travel with children easier.
With that seat-belt configuration, it is possible to use the "Skycouch" during take-off and landing.
The greatest challenge in certificating the modification was to assess the potential for occupant injuries – especially in adverse conditions, such as turbulence – as the "Skycouch" enables much more passenger positions than a conventional seat.
Reeves says that, in particular, families with children found more ways of using the sitting area than had initially been foreseen by the developers. For example, it is possible to turn only the middle and window seats into the sleeping position – with passengers leaning against the side panel – while the aisle seat is conventionally used with the leg-rest down.
After initial STCs were gained from New Zealand's civil aviation authority, SWS is now working to gain approvals from the European Aviation Safety Agency.
Smith says the two partners are considering applying for an STC from the US Federal Aviation Administration.