WASHINGTON - The US Federal Aviation Administration announced Wednesday it would increase the required flying hours for co-pilots significantly, four days after the deadly crash landing of an Asiana Airlines Boeing 777 commercial plane in San Francisco.

The Federal Aviation Administration said it would require co- pilots, also known as first officers, to have 1,500 hours of flight training for their certification to fly US passenger and cargo airlines, which is a huge jump from the 250 flight hours previously required.

The rule also requires co-pilots to have an aircraft type rating, which involves additional training and testing specific to the airplanes they fly.

"We owe it to the traveling public to have only the most qualified and best trained pilots," said Anthony Foxx, the new US Transportation Secretary in a statement.

FAA Administrator Michael Huerta said the new standards for pilot qualifications would make flying on US airlines safer.

"The rule gives first officers a stronger foundation of aeronautical knowledge and experience before they fly for an air carrier," Huerta said. "With this rule and our efforts to address pilot fatigue -- both initiatives championed by the families of Colgan flight 3407 -- we're making a safe system even safer."  

The agency said the new regulations stem in part from the tragic crash of Colgan Air 3407 in February 2009 that killed 50 people. The rule also addresses a Congressional mandate in the Airline Safety and Federal Aviation Administration Extension Act of 2010 to ensure that both pilots and co-pilots receive the Airline Transport Pilot certification.

The announcement comes four days after the Asiana Airlines crash in San Francisco that killed two Chinese passengers and wounded more than 180 people. The Boeing 777-200 aircraft carried 16 crew members and 291 passengers, including 141 Chinese, 77 citizens from the Republic of Korea and 61 Americans.

The National Transportation Safety Board has said the Asiana airplane was flying too slowly as it attempted to land at San Francisco International Airport. The agency has also revealed that the pilots of the airplane discussed aborting the attempted landing seconds before the plane crashed into the ground.

The experience of pilots have been a major focus of the Asiana Airlines crash as the company revealed that one pilot of the crashed airplane had only 43 hours of experience flying the Boeing 777.

But the US investigators said the investigation to the cause of the crash remained to be at the initial stage. The black boxes of the crashed aircraft -- the cockpit voice recorder and the flight data recorder - have been sent back to the federal agency' s headquarters in Washington D.C. for lab work.