Airbus has won permission for its twin-engined A350 to fly more than six hours on one engine in the event of a breakdown, winning over rival Boeing’s Dreamliner by 40 minutes.
The European Aviation Safety Agency granted the Airbus jet Extended Operations, known as ETOPS, of "beyond 180 minutes", but will allow pilots to fly the A350 for up to 370 minutes if one engine shuts down, Airbus said.
The approval allows the A350 superjumbo to fly almost any passenger route.
ETOPS rules determine the maximum flying time on one engine that jets can stray from the nearest airport at any point during their journey - so they can make it back safely in the event the other engine fails.
That ceiling determines the routes that modern twin-engined jets can take over deserted areas and oceans and is therefore seen as crucial to the sales pitches for such aircraft.
The maximum A350 diversion time of six hours and 10 minutes is equivalent to a maximum diversion distance of 2,500 nautical miles (4,630 km), an industry record, Airbus said.
Boeing's 787 Dreamliner has clearance to operate for 330 minutes on one engine, but the difference between the two categories is widely viewed as a marketing one since both jets will have enough margin to operate on most commercial routes.
The ETOPS rules are subject to separate clearances that must be sought by each airline.
Engine and aircraft makers say in-flight engine shutdowns are extremely rare and that jets seldom have to divert over such large distances. But manufacturers must demonstrate an aircraft can fly long diversions and airlines must prove they have the training in place to prepare for this.
Aircraft descend to a lower altitude and fly at slower speeds when forced to divert by the loss of one engine.
It is the first time a wide-body jet has been granted such autonomy before entering service, but questions remain over whether and when the US Federal Aviation Administration will issue similar flexibility for airlines under its jurisdiction.
The FAA said last week it would grant its own safety certification for the A350 by the end of October.
"We can't speculate on what ETOPS rating the A350 may receive because we haven't yet awarded the type certificate," a spokesman for the agency said later, asked about its stance towards extended operations for the jet.