Boeing has announced a long-term partnership with the Government to double its number of jobs in the UK.
The US plane maker intends to build a new £100 million facility for the P-8A Poseidon military aircraft at RAF Lossiemouth in Moray.
It will make the UK its European base for training, maintenance, repair and overhaul across its defence fixed-wing and rotary platforms.
Boeing has doubled its UK workforce over the past five years to more than 2,000 people.
The plans announced at the Farnborough International Airshow in Hampshire are expected to result in a further 2,000 jobs.
Boeing also pledged to increase the bid opportunities it offers to UK suppliers in an attempt to double their work with the manufacturer.
Prime Minister David Cameron said: "I want the UK to continue to be at the forefront of the global aerospace industry, both civil and defence.
"That's why I'm delighted that we can announce today a long-term strategic initiative with Boeing that will create thousands of jobs, secure investment in R&D and create opportunities for the supply chain, as well as delivering on our defence commitments.
"Boeing is one of the world's most respected aerospace companies. This long-term commitment shows the UK is open for business, and attractive for investment."
Boeing chairman Dennis Muilenburg said: "Boeing is committed to the UK Government's prosperity agenda and we share the goals of enhanced economic growth that the Prime Minister has set out to us."
The Ministry of Defence announced that Boeing will deliver 50 Apache AH-64E attack helicopters to the British Army under an agreement signed between the US and UK governments.
David Pitchforth, vice president and managing director of Boeing Defence UK Limited, said: "This is not only a major boost to the British Army but it will also mean long-term, sustained jobs in the UK as the vast majority of the training, maintenance, repair and overhaul will be done here over the service life of the aircraft.
"We are working closely with our extensive UK supply chain, including Leonardo-Finmeccanica Helicopters, to support initial operating capability of the aircraft in 2022."
Boeing's expenditure with the UK aerospace industry last year was £1.8 billion.
The company said that its activities support more than 60,000 UK jobs.
Mr Cameron met Virgin Atlantic founder Sir Richard Branson to view a flypast featuring an F-35 Lightning II stealth fighter and the Red Arrows.
The supersonic F-35 jets are capable of short take-offs and vertical landing, and are a highlight of the seven-day show in Hampshire which opened on Monday.
F-35Bs are due to enter service with the Royal Navy and the RAF from 2018.
The Lockheed Martin-built aircraft were due to appear at Farnborough in 2014 but were grounded following an engine fire.
The Red Arrows are not performing stunts at Farnborough for the first time in more than 50 years because of safety fears.
A decision was made to scrap the aerobatic displays following the Shoreham disaster last year, in which 11 people were killed.