MIAMI — The FAA has approved extended-range twin operations (ETOPS) for the Boeing 787 to 330 minutes, or 5.5 hours, on Wednesday.

The new rating extends the maximum distance the aircraft can fly away from a suitable landing field by 2.5 hours. The airplane was previously limited to 180 minutes, or 3 hours, largely due to concerns about the safety of its lithium-ion battery system.

The extension could open up dozens more route options, enabling the jet to fulfill its original mission of connecting exceptionally distant locations between remote stretches of land and water. Routes in the southern hemisphere are the most likely to benefit, connecting cities in Australia to South America and southern Africa and vice-versa.

That does not necessarily mean, however, that airlines can start flying such routes today. While the aircraft may have a new type approval, it will still need to receive its operational certificate from its home country. For example, Australia’s Civil Aviation Safety Authority would still need to certify the airplane on its own before Qantas could open up Melbourne-Johannesburg. Frequently the rating is earned via proving flights, which demonstrate that the route can be performed safely.

While the FAA’s decision delivers a vote of confidence in the jet, whose volatile lithium-ion battery’s periodically catch fire for reasons still unknown, not everyone is fully convinced. The US National Transportation Safety Board put out a report late last week on the batteries, in which it called the evaluation and certification of the system into question.

Specifically, the report noted that there was no way to test thermal runaway on the battery. The condition was the primary focus in several battery incidents that had grounded the airplane back in 2013 and limited the ETOPS rating from being extended beyond 180. The lack of a test led the NTSB to conclude that the FAA and Boeing may not have been able to accurately assess the dangers associated with a problem in flight. It has since recommended a test be created and that the risk on current 787s in service be re-evaluated.

Whether and when other nations will follow suit and award the Dreamliner its new rating remains unclear.

The only other commercial passenger aircraft to receive an ETOPS 330 rating is the Boeing 777. It earned the rating in 2011.