Hawaiian Airlines trimmed its summer flying schedule because of engine trouble that has dogged one of Airbus SE’s most popular jets.

The carrier removed an extra summer flight between San Francisco and Honolulu and a seasonal flight between Oakland, California, and Kona, Hawaii, citing later-than-expected deliveries of Airbus A321neo planes. The delays are due to fixes on the Pratt & Whitney engines powering the single-aisle jetliners, Alex Da Silva, a spokesman for Hawaiian, said Friday.

The airline also pushed back the start of a new flight between Oakland and Lihue, Hawaii, to July from April. Regulators grounded some of Airbus’s A320neo family jets earlier this month after discovering a new problem with a newly introduced engine seal on Pratt’s geared turbofan. Pratt, a unit of United Technologies Corp., has since found a temporary fix that will keep the planes flying until it finds a permanent solution for the fault, which caused vibrations.

Hawaiian has taken two A321neo jetliners from Airbus, one of which was affected by the Pratt problem, Da Silva said. While that aircraft is expected back shortly, the engine fixes potentially will delay some deliveries of new planes, Da Silva said.

The carrier expects to take an additional nine of the A321neo jets by the end of the year, according to a regulatory filing by the company earlier this month.

“We’re working with Airbus and Pratt & Whitney to understand the extent of the impact,” Da Silva said.