A man has been remanded in custody over his alleged involvement in a demonstration that saw two military aircraft damaged at RAF Brize Norton.
Muhammad Umer Khalid, 22, faces charges relating to criminal damage and compromising the security of the United Kingdom.
The incident in June saw a group of protesters break into the Oxfordshire air base and spray paint on two RAF Voyager planes, causing what police said was £7m of damage.
Palestine Action claimed the incident, saying it was a protest against the UK's weapons sales to Israel. The group was proscribed as a terrorist organisation soon after.
Mr Khalid appeared at Westminster Magistrates' Court wearing a black hoodie and grey tracksuit. He spoke only to confirm his name and address.
Prosecutor Peter Ratliff told the court the alleged offending happened at about 01:40 BST on the morning of 20 June.
Two jet engines, one on each Voyager aircraft, had to be replaced following the incident at a cost of £2.5m each, the court heard.
Fire extinguishers marked with the words Palestine Action and Palestinian flags were recovered at the scene.
The court heard Mr Khalid, of Stockport, was born in Manchester and was a British citizen. He was arrested at an address in Bedford on Friday.
He was denied bail and was remanded in custody for his next appearance at the Old Bailey on 22 August.
Mr Khalid is the fifth person to be charged in connection with the incident.
Amy Gardiner-Gibson, 29, Jony Cink, 24, Daniel Jeronymides-Norie, 36, and Lewis Chiaramello, 22, were all remanded in custody following a hearing at Westminster Magistrates' Court last month.
They will next appear together at the Old Bailey for a plea hearing on January 16, 2026. A provisional trial date is set for 18 January, 2027.