A series of defects found in Lockheed Martin’s F-35 fighters pose a hurdle to its plans to sell the costly next-generation fighter jets to U.S. allies, including South Korea.

This week, the U.S. Defense Department said a small amount of smoke in the aircraft’s cockpit was found during the testing process. Based on its initial assessment, the Pentagon said the problem appeared to be isolated and software-related.

The F-35 jets were also grounded for the second time this year recently because of a small crack found in a test aircraft engine.

Amid a series of reports on these development problems, doubts have been cast over whether Seoul could acquire the radar-evading aircraft as planned, should it opt to purchase it.

Under the “FX-III” project, Seoul plans to purchase a high-end fleet of about 60 fighter jets with a budget of around 8.3 trillion won ($7.6 billion), seeking to deploy them from 2016.

Lockheed Martin’s F-35 Lightning II, Boeing’s F-15 Silent Eagle and the Eurofighter Typhoon made by European Aeronautic Defense and Space Company N.V. are cited as the likely candidates for the FX-III project. Seoul is expected to pick the winner by June.

Randy Howard, Lockheed Martin’s director of the Korea F-35 Campaign, dismissed the growing concerns over a possible negative impact on Seoul’s acquisition project.

“We are waiting for what the root-cause analysis would show, and I think that we will get that very quickly. The primary thing here is the safety of the aircraft and aircrew. But I don’t foresee any impact on the deliveries for Korea,” he told The Korea Herald.

“It is a natural part of the development and it is a benefit to a customer country which is going to procure an aircraft on which a thorough testing program occurred. At the end of 2016, you (Seoul) get exactly what you have been promised to get.”

Howard also dismissed concern over the rising price for the aircraft. Some news reports here said that the cost for Seoul to acquire 60 F-35 jets would rise to around 15 trillion won.

“That is not true. It is a fabricated number,” he said. “Korea is looking for deliveries in 2016, 17, 18, 19 and 20. Those years are when the F-35 production is going up very quickly, so the price is coming down. It is economies of (scale),” he said.

The F-35 has been co-developed with eight foreign partners excluding the U.S. ― Britain, Italy, the Netherlands, Turkey, Canada, Australia, Denmark and Norway ― since 2001.

The single-seat, single-engine F-35 jet with a maximum speed of mach 1.8 has three different variants.

The conventional takeoff and landing F-35A is for air force operations, while the F-35B is the Marine Corps’ short take-off and vertical landing variant and the F-35C is the Navy’s carrier-based version. Should it decide to purchase the F-35, Seoul would purchase the air-force version.

By Song Sang-ho (sshluck@heraldcorp.com)