The F-35 will not make an appearance on the prestigious opening day of the Farnborough Airshow, the show’s organizers have announced.

Show officials say that the aircraft is still awaiting clearance to fly from U.S. military airworthiness authorities who grounded all three variants of the fighter following a fire in a U.S. Air Force example at Eglin AFB, Florida on June 23, but add they are “hopeful that it will fly at the airshow by the end of the week.”

Investigators are continuing to explore the root cause of the incident, but the attention of their work is focused on the Pratt & Whitney F135 engine.

Despite the incident occurring on June 23, Pentagon officials only grounded the fleet on July 3.

The grounding has dramatically impacted the planned international debut of the aircraft, which was due to take place at the Royal International Air Tattoo at RAF Fairford on July 11. A plan to fly over the U.K.’s new aircraft carrier, HMS Queen Elizabeth during its naming ceremony on July 4 was also missed. Three F-35Bs and an aircraft from the Marine Corp’s VMFA-121 training unit are sitting at NAS Paxtuxent River, Maryland waiting for clearance to make the journey across the Atlantic, but the U.K.’s aircraft, BK-3 is still sitting at Eglin AFB waiting to fly to Patuxent River in order to make the journey.

Even if the aircraft manages to attend Farnborough, it will only appear in the flying display, operating from Fairford.

“Everyone involved in the project is working towards a positive result for attendance at the airshow this week, and we fully support the stance to never compromise safety of either pilots or show participants and we thank them all for their continued hard work,” the show organizers said in a July 13 press release.