The US Special Operations Command (SOCOM) and Boeing had to cut short the test flight programme of the YMQ-18A unmanned helicopter after one of the aircraft crashed in Belize on 4 September.

No-one was hurt when the aircraft - dubbed the A160T Hummingbird by Boeing - crashed on the flightline of the Central Farm general aviation airfield in Belize on returning from a mission.

The incident is still under investigation, SOCOM says, and the 45 days of testing that began on 1 August were halted one week early. Boeing, which was operating the aircraft at the time of the crash, and the US military were in Belize testing the new unmanned air vehicle and the experimental Forester foliage-penetrating radar. The UAV had the large, externally mounted radar onboard at the time of the crash, but it is not yet clear whether the sensor or the aircraft is a total loss, SOCOM says.

About 90% of the testing objectives were completed before the crash and the rest can be done in the USA, SOCOM says. Before the mishap, two UAVs had completed 28 flights in 27 days and logged a combined 94 flight hours, the command says.

In 2009, SOCOM announced the intent to purchase 20 A160 helicopters between fiscal year 2012 and FY2017 to fulfil a requirement for a long-endurance, vertical take-off and landing aircraft. The Hummingbird, with its patented adjustable rotor speed technology, holds the record for endurance in its class, at 18.7h.

Shortly before the 50-member team departed for Belize, a US Army Aviation Applied Techonology Directorate-owned A160 crashed on a California flightline. The cause of the 28 July incident is also still unknown and the investigation still ongoing, says Boeing.

“It went into autorotation,” said Boeing Military Aircraft director of unmanned airborne systems Vic Sweberg at a UAV conference in August. “It was pretty much a complete loss.”

Source: Flight International