The Farnborough Airshow will open today without its star performer – the F-35B Lightning II fighter jet.
The jet was supposed to be on display when the Queen named the Royal Navy's new aircraft carrier Queen Elizabeth earlier this month, but an engine fire on an F-35 in Florida last month led to the jet being grounded.
This meant the jet was also unable to appear at a military tattoo at RAF Fairford in Gloucestershire this weekend and, today, organisers of the Farnborough air show said the F-35 would not be at the show tomorrow.
They said: "The aircraft is still awaiting US clearance but we are hopeful that it will fly at the air show by the end of the week. Everyone involved in the project is working towards a positive result for attendance at the air show 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 MoD is committed to purchasing the F-35, in which UK aerospace company BAE Systems plays a major part, and the ministry has said that even if the F-35 can only appear for a small part of the event, which goes on until next Sunday, it will do so.
An MoD spokeswoman said: "The safety of pilots and aircraft has to be our priority. Of course, it is disappointing that the Lightning II has not arrived in the UK in time for the Royal International Air Tattoo but we fully support the decision not to grant clearance for the aircraft to make their first transatlantic flight to the UK until the technical investigations are complete.
"We are confident that the aircraft will return to flying soon and, should clearance be granted in the coming days, we will work with the US Marine Corps to facilitate the aircraft's participation in the Farnborough International Air Show."
She went on: "The UK remains fully committed to the F-35 programme. Technical issues are not unexpected during the development test phase of a new aircraft, especially one as advanced as the fifth generation Lightning II.
"The grounding is not expected to have a significant impact on the programme and we are on track for the UK's aircraft to achieve their initial operating capability in 2018."
Organisers are committed to making sure the pull out does not put a downer on this year’s event, which marks US aerospace giant Boeing's 40th anniversary of participating.
Among planes being shown off by Boeing are the new 787-9 Dreamliner passenger aircraft as well as the P-8A, a military derivative of the Boeing 737-800, while Boeing's big rival Airbus, whose planes' wings are made in the UK, will display the A380 superjumbo, the world's largest passenger plane, as well as the A350 XWB (extra-wide bodied).
As is usual at the show – held every two years – Boeing and Airbus will vie for orders, with some big deals expected to be announced over the next few days. In London last week Boeing forecast that the world's airlines will require almost 37,000 passenger planes over the next 20 years.