The Surrey Police helicopter is undergoing specialist repair
The Surrey Police helicopter has been put out of action by vandals who used an axe to smash five windows.
The force, which has used the aircraft 518 times so far this year, is now having to rely on helicopters from neighbouring forces.
Vandals broke into the helicopter base at Fairoaks Airport, Chobham, just before 2200 BST on 30 April.
A force spokesman said the incident was being investigated and security at Fairoaks was being reviewed.
He said it was not yet known how much the damage would cost to repair.
"Surrey Police is working with the maintenance contactor to ensure the aircraft is back on line as soon as possible," the spokesman said.
The EC135 helicopter is fitted with a thermal image sensor and a camera to transmit pictures to police on the ground.