The biggest airshow in the world will kick off today with a multi-billion pound order for new planes form Crawley based Virgin Atlantic, ITV News understands.
Prime Minister David Cameron will officially open the show.
It is thought Sir Richard Branson will be at the show to order 12 Airbus A350's worth around $4.3billion.
The passenger plane is environmentally friendly burning less fuel and making less noise. They will fly from Gatwick and Heathrow.
Around half of it is built in the UK, including wings and engines, with final assembly in France.
However the future of Airbus in the UK has been questioned by some following the Brexit vote.
Airbus is a company with bases all over Europe employing 60,000 people and it is not clear how much of the operation would continue here long-term.
A company spokesman says it is business as usual and there has been heavy investment in UK plants so there will be no immediate impact.
However, experts say overall trade will be down on the record £157 billion orders at Farnborough of two years ago.
This is due in part to airlines in the Far East and Asia seeing a slowdown in expansion, particularly of low-cost carriers.
Many of the orders placed for new planes in 2014 are still being built.
The show is expected to attract 100,000 people from every part of the world with 1,500 companies exhibiting both military and civil aviation. Monday to Friday is for the trade with the weekend seeing public days.
The show is a major contributor to the local economy and employs hundreds of local people while it is on.
New safety rules following Shoreham means the flight display area has been moved further away from spectators and some roads will be closed.
The Red Arrows will stage a flypast but not perform acrobatics following the tragedy.
Star of the show will be the new F-35 fighter aircraft which failed to show at the last Farnborough two years ago after an engine fire on one of the planes.
Each costs £100 million and 48 will be on the new aircraft carriers based at Portsmouth. In total the UK is buying 138.
An even bigger star on Friday and Saturday will be Major Tim Peake. It will be his first public appearance since his recent space mission.
He will be at the show to encourage young people to become interested in aerospace and engineering.
The show will also focus on drone safety with a special event at the weekend. It follows recent near misses at Gatwick and Heathrow with key safety messages.
And Boeing will celebrate its 100th anniversary with planes new and old.
The Post Office will also celebrate its centenary by sending letters by plane and back to France on Friday.