The largest military exercise run by the Royal Air Force in the UK for more than a decade is underway.
As part of Exercise Crimson Warrior, RAF, Royal Navy, US Marine Corps and US Air Force aircraft are operating from RAF stations across the country.
The exercise, which began on Monday, will run until 5 November and is being controlled by staff from 92 Squadron at RAF Waddington, Lincolnshire.
At the exercise's peak, more than 70 fast jets, multi-engine aircraft and helicopters will be conducting high-intensity tactical training together over the North Sea and north-east England, the RAF said.
It includes land-based exercises for F-35B stealth fighters and helicopters that will form the Carrier Strike Group Air Wing for the 2021 operational deployment of the Royal Navy's HMS Queen Elizabeth.
The aircraft carrier recently returned to port after undergoing Carrier Strike Group exercises which involved F-35Bs.
Exercise director, Group Captain Rob Barrett, said: "Exercise Crimson Warrior is the largest and most complicated flying exercise we have held for many years and it is a vital part of the preparation for HMS Queen Elizabeth’s first operational deployment.
"The exercise will challenge participants from both the UK and the USA's air forces in the full range of air and space power roles, and it has been just as much of a challenge to organise and run, particularly in the context of the COVID-19 pandemic.
"However, I am confident that the precautions we have taken have reduced the risks to participants and the public as much as practicable."
The exercise is a development of the regular Cobra Warrior exercises - widely regarded as the most challenging training for aircrew, according to the RAF.
It is designed to develop and test the tactical leadership skills of both aircrew and supporting personnel.
Cover image: Typhoons during Exercise Crimson Warrior (Picture: RAF).