The boss of Asiana Airlines yesterday defended the pilots at the controls of the Boeing 777 which crashed at San Francisco airport.

Asiana president Yoon Young-doo spoke yesterday as the investigation into Saturday’s crash focused on what went wrong in the moments leading up to the runway approach when the aircraft was flying too low and too slow.

Aviation safety experts questioned why the crew did not recognise the problem and take action before the flight clipped a sea wall then crashed on the runway.

Lee Kang-kook, the captain who was in training on the 777, had previously flown in to San Francisco 29 times as a co-pilot on Boeing 747s, Yoon told reporters at a briefing Tuesday in Seoul.

The co-pilot Lee Jung-min had flown into the airport 33 times, Yoon said.

“They each had 33 and 29 times of operational experience,” Yoon said before boarding a flight himself for San Francisco, calling the men “excellent pilots.”

“I can tell you that they were sufficiently qualified pilots,” the Los Angeles Times reported.

Lee Kang-kook had only 43 hours of experience on the 777. Lee Jung-min was his “training captain,” but he had only been certified as a training supervisor June 15, less than a month before the crash, Asiana representatives said.

Yoon said he had personally apologised to the families of two Chinese girls who were killed in the crash.