Air Niugini has stopped some flights to Goroka because guiding lights have been stolen.
The National newspaper says F28 flights were stopped at the beginning of this month after thieves stole the lights from the airport's runway.
F28 aircraft depend on these Visual Approach Slope Indicator System lights to guide pilots to land.
Air Niugini doesn't want to risk flying the plane to because of possible early morning fog.
The flights are now being done with Dash 8 aircraft which do not need the navigational lights and can land and take off without much difficulty.
