After the landing gear on a South Korean F-35A stopped working during a major systems malfunction, the pilot chose not to eject and instead landed the jet on its belly -- walking away without any injuries.

The heart-stopping incident on Tuesday, at an air force base in the west of the country, has prompted a probe during which South Korean F-35s will be grounded.

"With the investigation under way, the entire (F-35) fleet is suspended from flying," a defence ministry official told AFP.

South Korea ordered 40 F-35A variants from its American maker Lockheed Martin in 2014, receiving the first batch five years later.

Republic of Korea Air Force vice chief of staff Shin Ok-chul shared the dramatic details at a parliamentary hearing on Wednesday.

The F-35A was flying at low altitude when the pilot heard bangs, prompting him to check aircraft systems, Shin told lawmakers.

"All systems had stopped working except flight controls and the engine," he said, adding that the pilot then chose not to eject and decided to attempt a belly landing.

The military sprayed a special foam on the runway at the air force base to prevent an explosion from the friction caused by the plane making contact with the surface at high speed, Shin said.

He said it was the first time a belly landing was attempted in an F-35.

The supersonic F-35 Lightning II is one of the most potent and agile fighters in the world, featuring stealth technology and advanced communications.

Its three variants are designed for a wide variety of missions.

And while its per-unit cost has come down in recent years, it is considered the most expensive weapons system ever developed by the United States.

The programme has also been plagued by numerous delays, cost overruns and technical setbacks.

Before the South Korean incident, the jet's most recent accident involved a British F-35B plunging into the Mediterranean during takeoff from the HMS Queen Elizabeth aircraft carrier in November.

Its pilot ejected safely.

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LOCKHEED MARTIN