Kabul — One of Canada's spy planes has crashed and gone missing in Afghanistan, almost two months to the day after another crash that temporarily halted the unmanned surveillance aircraft, or UAV, program.

“We don't know what happened,” Major Dyrald Cross said. “All we know is that it crashed.”

That leaves the Canadian Forces in Kabul with no more spy planes. They had four of them, but two others were damaged in “hard landings.”

A plane that crashed on Nov. 21 was the first to be destroyed after its parachute failed to open as the aircraft descended.

“This [latest] one, the causes are undetermined at the moment,” said Major Cross, who is in charge of the UAV program.

When the plane went down unexpectedly Tuesday, controllers were unable to pinpoint the crash site before dark. A crew of soldiers deployed to search out the aircraft were also unsuccessful in locating it.

“We know roughly where it is,” Major Cross said, “but it was too dark so we're waiting until morning to make sure the area is safe and have a better opportunity to find it in the daylight.”

Unlike commercial or manned aircraft, the UAV contains no beacons to direct searchers to its location. However, the software included in the machine can be tracked through a satellite-based Global Positioning System.

An investigation will be launched to determine why the plane's 65-horsepower Bombardier engine shut down unexpectedly, causing the 3 1/2-metre-long plane to fall to the ground.

The spy planes had been used by the NATO-led International Security Assistance Force since mid-December, when testing of the $33-million, high-reconnaissance system was completed.

The UAVs are launched by catapult from the back of a truck, and travel at almost 150 kilometres an hour, capturing video through cameras mounted in a ball on the underside of the aircraft. There is also a forward-looking, wide-angle camera mounted in the UAV's nose from which ground “pilots” can fly the aircraft by sight.

Built by Sagem of France, a subsidiary of Orlicon Canada, the planes were able to peer down on Kabul and the city's surrounding mountains to provide surveillance information to soldiers on the ground. In fact, it was used to aid Canadian soldiers as they raided a compound in the Afghan capital Sunday in search of drug smugglers with possible connections to a terrorist organization.

On Tuesday, Lieutenant-Colonel Don Denne confirmed that evidence was found “linking the compound and those in it to both drug trafficking and terrorist groups.”

However, when pressed, Col. Denne said he couldn't provide further details, citing security concerns.

“We've got certain items of interest including weapons, small amounts of narcotics and cash,” he added without getting specific. “We don't want anybody out there, and especially a terrorist group, to know what we are interested in, what we have found.”

Sixteen men were detained during the raid, although it's unclear whether any charges have been laid or whether any of them remain in custody.