The Marine Corps' version of F-35 has a unique feature that could have played a role in the South Carolina crash

An F-35B aircraft approaches a KC-130J Super Hercules aircraft to re-fuel as it flies over the North Sea having taken off from RAF Fairford on July 1, 2016, in Gloucestershire, England.
An F-35B aircraft approaches a KC-130J Super Hercules aircraft to re-fuel as it flies over the North Sea having taken off from RAF Fairford on July 1, 2016, in Gloucestershire, England.Matt Cardy/Getty Images
  • The debris of a crashed F-35 was found Monday in South Carolina after its pilot ejected during a mishap Sunday.

  • It's unclear why the pilot ejected, but the jet may have flown on autopilot for some time afterwards.

  • Though it's not certain, a special seat feature in the F-35B could've played a role in the unusual incident.

Even after debris from a missing F-35 stealth fighter was discovered in South Carolina earlier this week, questions remain about why and how the pilot bailed out of the jet in the first place.

A US official told the Associated Press the pilot was "forced to eject" following a malfunction, hinting that part of the mystery surrounding the F-35B crash may actually involve a pilot safety feature unique to the Marine's jump-jet version of the stealth fighter.

On Sunday, Joint Base Charleston reported a "mishap involving an F-35B Lightning II jet" in which the pilot ejected from the fifth-generation fighter aircraft. The base didn't provide further information on the incident or what caused the "mishap." A base spokeperson told NBC News the jet was left in autopilot mode and may have remained airborne for some time, though they later said they didn't know for sure.

Authorities were, however, sure the aircraft was down as of midday Monday, and a few hours later, officials confirmed a debris field was discovered in Williamsburg County about two hours northeast of Joint Base Charleston. "The mishap is currently under investigation, and we are unable to provide additional details to preserve the integrity of the investigative process," it added in a press release.

While many of the specifics remain under wraps or are perhaps simply still unknown at this time, there's a chance a feature specific to the Marine Corps' F-35B model could've played a role in how and when the pilot ejected. With the auto-eject system, it might have been involuntary.

Two U.S. Marine F-35B Lightning II Joint Strike Fighters complete vertical landings aboard the USS Wasp (LHD-1) during operational testing May 18, 2015.REUTERS/U.S. Marine Corps/Lance Cpl. Remington Hall/Handout

Similar in function to the Harrier jump jet, the B variant of the F-35 Lightning II Joint Strike Fighter is a short takeoff/vertical landing model. It features a unique auto-eject capability and is the first US aircraft to do so, and it was included for a reason.

The F-35Bs used by the Marine Corps can hover kind of like a helicopter, which is a beneficial capability for use aboard amphibious assault ships and on airfields with short runways. It does this using a large lift fan in the center of the jet's fuselage. If that fan were to fail, or power from the engine were to cut out, it's possible the jet could flip over and fall faster than a pilot could react to either stabilize the aircraft or eject themselves.

In a dangerous situation for the pilot and aircraft, the auto-eject would likely activate, although the parameters for this function are unknown. All that's clear is that the Martin-Baker US16E ejection seat can be automatically engaged without pilot input.

Back in December 2022 when, during a test flight at Naval Air Station Joint Reserve Base Fort Worth in Texas, an F-35B was hovering above the runway before suddenly dropping, bouncing, jerking forward, and then slamming into the runway nose-first. The hard impact caused the F-35B to spin around and smoke before the pilot ejected.

It's possible that, had the aircraft rolled over in a different direction, the pilot wouldn't have enough time or space to eject themselves.

It's currently not clear if the F-35's auto-eject safety mechanism influenced Sunday's incident and when or how the pilot ejected from the plane beyond what an anonymous official told the AP. The results of the investigation, which could still be months away, will reveal more.

In addition to the B variant, there is also the F-35A conventional takeoff and landing variant designed for the US Air Force, and the F-35C carrier variant made for both the Navy and Marine Corps. The variants have different features that allow "military forces to achieve service-specific mission capability, while still taking advantage of the economies of scale that result from the parts and processes that are common to all three variants," according to the jet's manufacturer, Lockheed Martin.

The F-35 Joint Strike Fighter is a highly advanced fifth-generation fighter aircraft known for high-end capabilities and stealth. They are also exceptionally expensive, with a single F-35B estimated to cost around $100 million. The 60-year F-35 program, which includes jet development and maintenance, is expected to cost well over than $1 trillion, making the fighter jet the most expensive weapons program in US history.

Read the original article on Business Insider