Back in July, disaster was narrowly averted when an Air Canada Airbus A320 almost landed on a taxiway full of waiting aircraft, rather than the runway adjacent to it. On Sunday, another Air Canada A320 was on final approach to SFO when an air traffic controller instructed the pilots five times to go around but the Air Canada crew failed to respond and continued with their landing. Listening to the tower recording, you can hear the controller call and receive no response, then work to move aircraft out of the way for the A320. After landing, the Air Canada pilots reported a problem with communications, but it’s unclear if the radios were malfunctioning, on the wrong frequency, or if the pilots simply ignored them. You can read more about the incident at Aviation Herald.