A US Air Force F-35 pilot was forced to eject after nearly an hour spent on a mid-air conference call with engineers, trying unsuccessfully to fix a serious malfunction before the jet crashed on an Alaska runway.

Footage posted on social media earlier this year captured the aircraft spiralling toward the ground before erupting into flames, while the pilot parachuted safely away.

A report obtained by CNN said ice in the hydraulic lines of the nose and main landing gears caused the crash, stopping them from deploying correctly.

Shortly after takeoff, the pilot failed to retract the landing gear, and when lowering it again, the nose gear locked at an angle.

As he attempted to troubleshoot, the jet mistakenly registered itself as being on the ground.

He then joined a call with five Lockheed Martin engineers, circling the base for nearly 50 minutes.

Despite trying two “touch and go” landings to straighten the jammed nose gear, the attempts froze the hydraulics completely.

With the sensors continuing to signal that the plane was grounded, the jet became “uncontrollable,” forcing the pilot to eject.

An inspection later revealed that a third of the hydraulic fluid in the nose and right main landing gears was contaminated with water. Just over a week later, the same base saw another “hydraulic icing” incident, though that jet landed without incident.

At the time of the crash, temperatures were recorded at -18°C.

The report concluded that “crew decision-making, including those on the in-flight conference call,” and weak “oversight for the hazardous material program” contributed to the failure.

The F-35 programme, led by Lockheed Martin, has been dogged by criticism over high costs and production flaws.

While the price per jet has dropped from around $135.8 million in 2021 to $81 million in 2024 under a Pentagon deal, the programme is projected to run until 2088 with lifetime costs exceeding $2 trillion, according to the US Government Accountability Office.