Engine glitches that have disrupted Airbus SE A320neo jet operations around the world may take at least three more months to resolve amid a scarcity of upgraded turbines, according to comments from one of the planemaker’s biggest customers, Deutsche Lufthansa AG.

Fixes for the snags afflicting the geared turbofan, or GTF, powerplant made by United Technologies Corp.’s Pratt & Whitney unit and its partners won’t immediately filter through to the Lufthansa fleet, according to the German carrier’s chief executive officer, Carsten Spohr.

“Our dialog with the manufacturers, especially Pratt & Whitney, on the big issues surrounding the A320neo engine suggests there’ll be no relief soon,” Spohr told staff in comments confirmed by Lufthansa. “For another few months we’ll be on our own. At the earliest, the fixes will come in November.”

While Pratt has eliminated the most pressing faults with the GTF, it’s having to juggle demand for replacement engines with the need to supply turbines to about 100 new planes that have been parked up awaiting the fix. That’s meant that Lufthansa and other early customers for the A320neo, most of them in Asia, are having to wait in line until spare turbines become available.

Pratt spokeswoman Jenny Dervin said all new A320neo engines now include upgraded components. She added that the U.S. company is working closely with clients including Lufthansa to move planes to the latest configuration.

Airbus—which reset delivery targets for the A320neo after the glitches caused a near three-month freeze in shipments—said it’s building up a pool of spare engines to keep the established fleet in the air. The number of new jets parked has also been cut to between 60 and 70, spokesman Stefan Schaffrath said.

Compensation

The planemaker has said that the burden of compensation claims for late deliveries and disruption is likely to fall mainly on U.S.-based Pratt.

The Lufthansa group has 122 A320neo-series jets on order. While deliveries began 2 1/2 years ago, it has so far received only about half of the 20 planes due so far, and those delivered have flown just 50 percent of the usual hours, so that overall capacity is one-quarter of the expected level, Spohr said.

While the reduced complement of jets is operational right now, the CEO told staff that its engineers have scoured the globe for reserve engines to keep operations running, but that there are none available. “We just used our last spare engine this morning,” he said on Aug. 14. “That’s the first time I can remember that we operate without a single engine in reserve.”

Among issues afflicting the GTF, Pratt has fixed a faulty knife-edge seal in all turbines by reverting to an older design while working on a more durable replacement. The retrofit of a new combustor has yet to be completed, with the glitch causing some recent groundings at India’s IndiGo, whose aircraft fly in hot, dusty conditions that put a strain on engines.

There’s also a population of jets without the latest version of an oil seal that will be added as their powerplants undergo scheduled overhauls, Dervin said.

Utilization Gap

In the week through Aug. 16, some 15 A320neo-series planes were standing idle out of the 140 delivered with GTF engines, according to UBS research. That compares with seven grounded out of the 205 powered by the rival Leap turbine from General Electric Co. and Safran SA.

Derwin said around 10 aircraft are generally out of action at any one time, mostly for accelerated maintenance visits necessitated by the glitches.

The GTF jets were in the air for 7.7 hours a day on average, UBS said, a utilization almost 20 percent lower than the 9.3 hours achieved by the Leap.

United Technologies CEO Greg Hayes said last month that “for the most part” the company had enough spares to deal with outstanding issues and that most teething problems relating to the engine “have at least been identified.”

Toulouse, France-based Airbus has orders for more than 4,000 A320neos, making the model its fastest-seller ever.