The aircraft took off from Renton in Washington (Picture: Boeing).
The RAF's new maritime patrol aircraft has made its first flight.
The Boeing Poseidon P-8A took off from Washington and completed a 90-minute flight which included "key testing", according to Boeing.
Officials from the Ministry of Defence (MOD) and RAF personnel were there to watch the jet's maiden flight.
Air Commodore Richard Barrow said: "This is a great milestone in the UK P-8A Poseidon’s journey to the UK, as we are one step closer to its arrival in Scotland.
"The platform will enhance the UK’s maritime patrol capability with advanced, state-of-the-art technology.”
The P-8A, which is designed to hunt and destroy submarines, is now set to have its military systems installed.
Watch: The jet's first take-off
Boeing says the RAF will take delivery of the first aircraft later this year.
RAF aircrew will then undergo a period of training with the aircraft at US Naval Air Station Jacksonville before flying back to the UK early next year.
Nine P-8A Poseidons will eventually operate from RAF Lossiemouth, which is undergoing a £132 million makeover ahead of the arrival of the aircraft.
The UK signed a £3 billion deal with Boeing in July 2016 which covered the cost of the nine P-8As as well as training, maintenance and support.
Norway, New Zealand and South Korea are also set to receive delivery of the aircraft in the coming years.