An air cargo plane took off in the wrong direction at Kona International Airport last week and was headed toward a go! Airlines plane that was coming in for a landing on the same runway.

The air traffic controllers union blamed the incident on short staffing at the Kona airport, where contractors -- not federal, unionized controllers -- direct air traffic.

The incident does not qualify as a near collision, because both aircraft were never closer than 3 miles apart, Federal Aviation Administration officials said. The FAA has classified it as "pilot error."

The incident raises safety questions. It happened at Kona International Airport on May 19, at about 8 a.m. when an Alpine Air Cargo plane was given permission to take off.

"The controller apparently missed it, the aircraft in question lined up on the right runway, but facing the wrong direction," said Scott Sorenson, the local president of the National Air Traffic Controllers Association. "And so therefore you're taking off into the face of another aircraft coming opposite direction."

The Alpine Air Cargo plane was headed toward a go! Airlines jet that was coming in for a landing on the same runway, bringing passengers from Honolulu.

The air controller had the Alpine Air plane turn away, over the ocean, to avoid getting dangerously close to the incoming go! plane, which landed without incident, the FAA said.

The air traffic controllers union said there was just one controller on duty that morning, leading to dangerous short staffing.

"These people are working by themselves in a job that would normally entail three people, two to three people, which triples their workload. So that means they can't pay attention to detail like they need to," Sorenson said.

The FAA contracts out traffic control services in Kona to an Australian agency called Airservices Australia, meaning that contractors and not federal employees handle plane departures and landings.

The union, National Air Traffic Controllers Association, wants the federal government to end the contract when it expires this year and bring back FAA employees to the Kona facility.

The contractor, Airservices Australia, is a government-owned corporation that operates 26 air traffic control towers at airports across Australia and six towers at United States territories in the Pacific, including airports in Kona, Lihue and Molokai.