For at least 20 minutes Saturday morning, pilots were unable to make contact with air traffic controllers at the Boise Airport.
The Federal Aviation Administration says it is investigating what happened but would provide no other details.
“All I can tell you at this time is that we are looking into it,” said Allen Kenitzer, a regional FAA spokesman based in Renton, Wash.
No incidents were reported as a result of the inability to contact the controllers.
The first commercial flight of the day, a Delta flight to Minneapolis, was not scheduled to depart until 5:30 a.m., and no incoming flights were scheduled to arrive until just before 8 a.m.
Two Air St. Luke’s helicopters — one leaving the health system’s Downtown Boise hospital and returning to the airport, and a second one leaving the airport between 2:30 a.m. and 2:40 a.m. — launched alternate procedures after failing to reach air controllers.
“We’re about to land at the aviation air center. We’ll remain clear and north of the runways,” one of the pilots announced over the radio in a recording provided by the online service LiveATC.net.
By announcing the helicopter’s movements over the radio, it allowed any other aircraft monitoring the frequency to know there was an aircraft heading to the airport. It also alerted the airport’s operations office that something was amiss, St. Luke’s spokeswoman Anita Kissée said.
“The protocol is to call out and to announce their launch report over the radio, their movements and coordinates,” Kissée said.
Likewise, airport operations officials were unable to establish communication with the tower, airport spokesman Sean Briggs said.
“At that point in time, we did send police and fire (crews) over to the tower,” Briggs said.
Briggs would not say what they found, referring further questions to the FAA.