WASHINGTON — The pilot of the jet that crash-landed at San Francisco’s airport last summer worried privately before takeoff about handling the Boeing 777, especially because runway construction meant he would have to land without any help from a common type of guidance system.

And neither the trainee nor an instructor pilot in the cockpit said anything when the first officer raised concerns four times about the plane’s rapid descent.

After the July 6 accident, which killed three people and injured more than 200, Lee Kang Kuk told National Transportation Safety Board investigators that he had been concerned he might “fail his flight and would be embarrassed.”

Lee’s back story emerged Wednesday in documents released at an NTSB hearing called to answer lingering questions about the crash of Asiana Flight 214.

Though Lee was an experienced pilot with the Korea-based airline, he was a trainee captain in the 777, with less than 45 hours in the jet. He had not piloted an airliner into San Francisco’s notoriously tricky airport since 2004, according to NTSB investigator Bill English. So far, the investigation has not found any mechanical problems, he said.