SEOUL (AFP) - South Korea's Asiana Airlines admitted for the first time on Tuesday that pilot error was the "probable cause" of last year's San Francisco crash in which three people died.

However, in a press statement, the airline cited other contributing factors including technical issues with the plane's auto-throttle system.

As it came into land after an otherwise routine flight from Seoul to San Francisco on July 6, Asiana Airlines Flight 214 clipped a seawall with its landing gear, skidded off the runway and burst into flames.

"The probable cause of this accident was the flight crew's failure to monitor and maintain a minimum safe airspeed during a final approach," the Asiana statement said.

This resulted in the plane deviating below the intended glide path on its runway approach which caused it to hit the seawall.

Three people were killed and nearly 200 injured in the crash.

The statement added that the cockpit crew had been misled by "inconsistencies" in the Boeing 777-200ER's automated systems, which led them to believe the auto-throttle was maintaining the set airspeed.

Asiana said its conclusions had already been submitted on March 17 to the US National Transportation Safety Board (NTSB), which is leading the investigation.

The NTSB insists the autopilot only plays a complementary role and that pilots are obliged to monitor their equipment and pay attention to their surroundings to prevent crashes.

The board has said the autopilot was switched off about three miles (4.8 kilometres) out, and that the airspeed dipped as low as 103 knots (191 kilometers per hour), or 34 knots below the ideal approach speed.

The aircraft descended so low that an array of approach lights at the end of the runway - a key visual aid to landing - showed four red lights, a situation that would call for an aborted landing.

Asiana has defended the two pilots, Lee Kang Kuk and Lee Jung Min, saying they were "competent" aviators who had flown dozens of times to and from San Francisco.