SAN FRANCISCO — As Flight 214 descended over San Francisco Bay, both Asiana Airlines pilots were trying something new.
In the left seat of the cockpit sat Lee Gang-kuk, a 46-year-old pilot with just 35 hours of experience flying a Boeing 777, who was landing the big jet for his first time at San Francisco International Airport. At his right was Lee Jeong-Min, a trainer making his first trip as an instructor pilot.
While the two men had years of aviation experience, this mission involved unfamiliar duties, and it was the first time they had flown together. The flight came to a tragic end when the airliner crash-landed Saturday, killing two passengers and injuring many others.
National Transportation Safety Board chairman Deborah Hersman said Wednesday the pilot told investigators he was blinded by a light at about 500 feet, which would have been 34 seconds before impact and the point at which the airliner began to slow and drop precipitously. She said lasers have not been ruled out, though it was unclear if the flash may have played a role in the crash.
The agency also said that after the crash landing, passengers were told to stay seated while the crew contacted the control tower, and people did stay inside the aircraft until 90 seconds later when a fire was spotted outside the plane.
At that point, the doors were opened and escape slides were inflated. Two flight attendants were pinned by slides that inflated inside during the impact.
Experts say investigators trying to piece together what went wrong will consider the report about the light and many other factors including the pairing of the pilots, who were assigned to work together through a tightly regulated system developed after several deadly crashes in the 1980s that were blamed in part on inexperience in the cockpit.
Pilots are typically paired by management and are not allowed to choose their partners in the cockpit.
Meanwhile, airline pilots will need to have more experience and pass more rigorous tests under the most significant increase in commercial flight-crew standards in decades, the US government announced Wednesday.
The biggest changes will come for copilots, who will need to have at least 1,500 hours of flight time to be hired, up from the current minimum requirement of 250 hours, according to the US Federal Aviation Administration.
The regulation, required by Congress in 2010, would grant some exceptions to the 1,500-hour standard. A military pilot would need 750 hours of total time and someone holding a bachelor’s degree with an aviation major could qualify with 1,250 hours of flight time.
Congress passed the law requiring the regulation in response to the Feb. 12, 2009, crash of a regional turboprop plane operated by Pinnacle Airlines’ former Colgan unit that killed all 49 aboard and that was blamed on pilot errors. It was the last fatal airline accident in the United States before the July 6 Asiana Airlines crash.
Details emerging from pilot interviews, cockpit recorders, and control-tower communications indicate that Lee Gang-kuk, who was halfway through his certification training for the Boeing 777, and his copilot and instructor, Lee Jeong-Min, thought the airliner’s speed was being controlled by an autothrottle.
Inspectors found the autothrottle had been ‘‘armed,’’ or made ready for activation, Hersman said. But investigators are still determining whether it had been engaged.