The main runway at Portland International Jetport is back in operation, ending disruptions during construction.

The runway reopened three days ahead of schedule on Friday, allowing resumption of normal flight patterns and a restoration of the airport’s instrument landing system.

During the closure, flights were using a shorter runway and some had to be diverted during times of poor visibility.

It also caused a change in air traffic patterns over Portland, South Portland, Scarborough and Westbrook, with low-flying aircraft passing over neighborhoods unaccustomed to the noise.

The $13.7 million project that began April 18 involved repaving the 7,200-foot runway in addition to installing new LED lighting.