A police spokesman said there was "some involvement" with a vehicle at the end of the runway.
"The plane clipped a loader and then crashed," he said.
It wasn't known if the plane crashed on take-off or landing.
The Civil Aviation Authority had been alerted, he said, and the fire service were also on the scene.
Meanwhile, emergency services raced to a rural area north of Auckland today after a plane crash was reported - but it turned out to be a local aero club pilot practicing forced landings.
A woman who lives near Waitoki called police just after 3.30pm to report what she thought was a crash.
The Herald understands she heard a "light plane'' flying overhead, then heard the engine stop and a "crash''.
A police spokesman confirmed officers were on their way to Pebblebrook Rd to investigate.
But soon after a Fire Service spokesman said the 111 call was a false alarm.
The sound the woman heard was in fact the aero club pilot. After the call the club confirmed to emergency services that the pilot was still flying and had not crashed.