Another Air Canada jet safety issue at San Francisco airport

The air traffic control tower is in sight as a plane takes off from San Francisco International Airport, Tuesday, Oct. 24, 2017, in San Francisco. The Federal Aviation Authority is investigating why an Air Canada plane ignored repeated orders by an air traffic controller at the airport to abort a landing on Sunday, Oct. 22. The incident comes three months after another Air Canada plane nearly landed on a crowded taxiway at the airport. (AP Photo/Jeff Chiu)

SAN FRANCISCO (AP) — Six times the control tower at San Francisco International Airport ordered an incoming Air Canada plane to abort its landing, fearing another plane might be on the runway. Each time, the order went unanswered.

Finally, air traffic controllers Sunday night took out an emergency red light and aimed it outside their window toward the jet to try to get the pilots’ attention. That didn’t work either, the plane landed and one of the pilots then radioed that he was having problems with the radio.

“That’s pretty evident,” the controller responded.

The Federal Aviation Administration said Tuesday it is investigating the second serious safety issue in three months involving an Air Canada passenger jet landing at San Francisco airport.

In July, an Air Canada jet with 140 people on board nearly landed on a taxiway where four planes were waiting before takeoff, prompting the FAA to issue new rules for nighttime landings and control tower staffing at the airport.