There wasn’t much to see on the airfield of Pittsburgh International Airport on Thursday morning, although there was plenty going on.

With reports of less than a quarter-mile of widespread visibility for parts of the region, the National Weather Service issued a Dense Fog Advisory through 10 a.m.

Despite the weather, however, flights continued to take off and land at PIT. Patrick Carreno, VP of Airport Operations, explained the airport can accommodate aircraft with the proper flight instruments, including auto-land capabilities, in basically any level of fog conditions.

“Fog is really not too big of a deal from an airport operations standpoint – it’s just the matter of whether or not the airlines have the aircraft and crew with the necessary qualifications to land in low visibility,” Carreno said.

Most airlines are equipped with aircraft that have modern flight instruments, which provide pilots with information including altitude, speed, direction and even the slope of the aircraft’s elevation. Aircraft with auto-land systems can also automate an entire landing procedure, allowing planes to land in various weather events without manual control from the flight crew.

Although planes can handle those situations without much help, the Airport Operations team still implements specific plans for various weather events. For example, operations offered lighted trucks to help guide aircraft to gates Thursday morning, Carreno said.

“From a support perspective, our operations team is available to help in any way that we can when necessary,” said Carreno. “We don’t get a lot of these types of situations, and today we let the airlines know that this service would be available, but there really wasn’t any need for it.”

PIT also features runways with Category III Instrument Landing System (ILS) operations. CAT III ILS ratings feature powerful and advanced lighting systems, along with instruments on the ground that provide in-flight data to aircraft, which are especially helpful when landing in low-visibility situations.

Fog typically has a bigger impact for smaller planes that rely less on computers. Through Thursday afternoon, there were nine flight cancellations at PIT, with some caused by weather in other regions of the country, including Chicago.

However, a few flights on Southern Airways Express were grounded due to fog in Pittsburgh as well as Morgantown, West Virginia, according to Mark Cestari, the airline’s chief commercial officer, who added that it was a very unusual occurrence.

“One of the things we love about Pittsburgh is that regardless of the weather, the airport never closes,” Cestari said. “Southern typically has a 98-99 percent controllable completion rate; we hardly ever cancel flights for any reason except for something like this kind of unusual fog. Safety comes first, and that’s the same for any airline.”