Airline passengers can thank some fog and a group of construction trucks for the headaches they experienced during their travels through the Charleston International Airport Thursday and Friday.

Airport officials announced Thursday that a specialized navigation system used to notify passing aircrafts of their position was in need of repair after malfunctions prevented its signal from getting through to planes.

That led the airlines to cancel about a dozen incoming and outbound flights, leaving passengers in the lurch.

Officials were initially worried the navigation device, which looks something like an oversized bowling pin, was busted. The system is owned and operated by the Federal Aviation Administration.

But technicians determined Friday that nothing was wrong with the system after performing a fly-by test in which a plane picked up the signal with no problems, according to the FAA. Instead, officials found a much more mundane explanation: a group of construction trucks had parked too closely to the system, interfering with its the radio signal.

Under clear conditions pilots can also rely on visual approaches to the airport, but Thursday’s heavy fog didn’t allow for a clear view of the runway, the FAA said.

Someone apparently moved the trucks Friday afternoon, because the navigation system was back up and running by 1:40 p.m., according to the FAA. Flights were back to normal by the afternoon, airport spokesman Becky Beaman said.

The FAA reported that it will work with Air Force, which owns the runway, to make sure vehicles remain clear of the navigation system in the future.

The hiccup caused delays for several passengers.

Darren Basicker of Indiana expected to be on a flight to Dayton, Ohio Thursday evening, but his flight was one of those cancelled.

Basicker said he was in Charleston on a golfing trip. He checked his golf clubs back in at the airport for a second time Friday morning.

His plane was expected to take off at 11 a.m. despite earlier estimates that incoming and outbound flights would be pushed back until noon.

“I’ll just keep my fingers crossed and see what happens,” Basicker said.

Beaman said some of Friday’s delays were due to several flights returning to Charleston after being diverted to Savannah and Columbia Thursday.

Beaman said the airlines contacted affected travelers Thursday and Friday. She emphasized the significance of passengers supplying their airlines with their cell phone numbers and emails.

“They want to be there to help the passenger,” Beaman said of the airlines.

Those expecting to greet passengers as they arrive should also contact the airline before heading to the airport, she said. “contact the person’s airline before you come out.”