The West Midlands Police helicopter has suffered "extensive damage" in a suspected arson attack, the force said.
Air traffic controllers raised the alarm when they spotted flames on the front of the helicopter at its landing site at Elmdon Airport about 0200 BST.
Assistant Chief Constble Gary Cann said: "We do suspect this is an arson attack, which is why we have launched a criminal investigation immediately."
He said the force would continue to provide air support "when necessary".
Forensic experts, detectives and airport security staff are working together at the scene.
The airport said no-one was injured in the incident.
The airfield was temporarily closed for about 30 minutes after the incident, an airport spokesman said.
"No scheduled passenger jets operate from this area," he said.
"No flights were affected and the airport is fully operational."
The helicopter was launched in September 2007 after being fitted with a high-definition video camera and a thermal camera system.
In 2006, a previous helicopter flew 3,315 operations in support of officers.
The Air Operations Unit, which runs the helicopter, was set up in 1989 to cope with increased demand for a force helicopter.
In March, a laser light was shone at the helicopter's cockpit as it flew over Birmingham.
A 17-year-old admitted in court to endangering the aircraft with the laser and he was given a 12-month referral order.