They set about the Surrey force’s chopper with axes — putting it out of action by smashing five windows.
The attack followed weeks of aerial surveillance on a travellers’ site where swish stolen cars and nicked goods are believed to be stashed.
A police source said last night: “The gipsies were furious because they kept getting buzzed by the helicopter.
A group of travellers wrecked a multi-million pound police helicopter which was being used to spy on their site.
The gang used axes to smash the £5million aircraft, after they leapt over a 4ft wall surrounding Surrey Police force’s helipad at Fairoaks airport, near Woking in Surrey.
After threatening staff working in the operations room, they set about wrecking the helicopter, smashing six of its windows and causing tens of thousands of pounds worth of damage.
The incident happened at 10pm yesterday after weeks of aerial surveillance on the travellers’ site, where detectives believe stolen goods have been hidden.
Officers were getting ready to raid the site after collecting evidence they had filmed from the air.
A police source said last night: ‘The gipsies were furious because they kept getting buzzed by the helicopter.
‘But no one expected this level of violence.
‘Before a raid is conducted we will observe the criminals from the air. That way we get an idea what we are likely to find, identify suspects and locate entrances and exits. Maybe we got too low.’
The aircraft is the only police helicopter in Surrey and is used mainly for chasing crime suspects in their cars, finding missing people and pre-planned surveillance operations.
The helicopter, which has a camera fitted under its nose that beams broadcast-quality footage to the control room, was airborne 214 times during April, an average of seven flights per day.
It is expected to be out of action for another two weeks while repairs are made.
Security at Fairoaks has been stepped up following the attack and neighbouring Metropolitan and Sussex forces are providing air cover for Surrey’s one million residents.
A Surrey Police spokesman said the identity of the mob members was ‘unknown’.
He added: ‘The incident is part of an ongoing investigation and security measures are being reviewed as part of this.
‘We are working with a maintenance contractor to ensure the aircraft is back on line as soon as possible.’