The chief of Hawaiian Airlines says the Federal Aviation Administration has certified the Airbus A321neo's Pratt & Whitney PW1100G-JM engine for extended over-water flights.
The news, confirmed by Pratt & Whitney, bodes well for Honolulu-based Hawaiian's plans to launch A321neo service in January 2018 and become the first North American operator of the P&W-powered A321neo.
Challenges remain – Airbus has still not delivered the first aircraft, and Hawaiian requires FAA certification to operate the type.
But Dunkerley remains confident the first aircraft will arrive in October and that Hawaiian will begin flights as planned.
"With each passing day, we gain more confidence in the delivery schedule," he tells FlightGlobal during an industry conference in Washington DC on 13 September.
Dunkerley adds the FAA has been "very helpful" by allowing Hawaiian to begin the A321neo operations certificate process prior to delivery of the first aircraft, helping minimise the period between delivery and start-of-service.
"There are a number of regulatory steps we have to go through," he says, such as proving runs, evacuation tests and approval of operating and training manuals.
The FAA several weeks ago granted a 180min extended twin-engine operations (ETOPS) certificate to the A321neo's available PW1100G-JM geared turbofan.
That approval follows a June ETOPS certification by the European Aviation Safety Agency of both the PW1100G-JM and the A321neo's other engine option, the CFM International Leap-1A.
The FAA did not immediately respond to a request for confirmation or additional information.
But Dunkerley's comments put to rest concern that early issues with the PW1100G might have delayed the FAA's ETOPS certification, which could have further delayed Hawaiian's launch plans.
Recent PW1100G issues included an inflight shutdown, a shortage of fan blades and problems with the engines' carbon air seal assemblies and combustor liners.
In an April research report, financial research company Wolfe Research raised concerns those issues might delay ETOPS certification and cause problems for carriers like Hawaiian.
The carrier has firm orders for 17 A321neos, with deliveries scheduled from October into 2020. It intends to deploy the type between Maui and Oakland on 8 January 2018.
Hawaiian plans to use the A321neo primarily between secondary Hawaiian destinations (those other than Honolulu) and cities in the western USA, it has said.
In late 2016, Hawaiian announced that delivery of its first three A321neos would be delayed by three months, until the fourth quarter of 2017.