Asiana Airlines admitted in a regulatory filing released Monday that its pilots failed to monitor and maintain a safe airspeed in a crash at San Francisco International Airport that killed three passengers last July.

The airline's explanation of how its pilots landed a state of the art airliner short of the runway on a clear, sunny day July 6 is contained in documents released Monday by the National Transportation Safety Board.

The documents likely set the stage for a battle over financial damages for the crash of Flight 214, a nonstop from Seoul, South Korea.

Asiana admitted that the "probable cause" of the accident was the flight crew's failure to monitor and maintain a safe airspeed and to initiate a go-around for another try at landing as required by company procedures.

"Given the pilots' experience and training, there are no obvious explanations for why they did not recognize the deteriorating airspeed and abandon the approach sooner," the airline said in its submission to the NTSB.

But it also blamed the Boeing 777 airliner's automation and warning systems for contributing to the disaster, along with what it said was a heavy workload imposed on the pilots by air traffic controllers on the ground.

Boeing's submission, also released Monday, placed the blame squarely on the pilots.

"This accident occurred due to the flight crew's failure to monitor and control airspeed, thrust level and glide path on short final approach," Boeing said.

Had the crew followed procedures and initiated a go-around for another landing attempt, the accident would have been avoided, Boeing said.

The Federal Aviation Administration, which operates the air traffic control system, referred questions to the safety board.

Board spokesman Keith Holloway declined to comment, citing an ongoing investigation.

Barry Schiff, a Camarillo aviation safety expert with 34 years as an airliner captain, said blaming automation as a contributing factor "is shifting blame where it does not belong."

Schiff said maintaining a safe airspeed is one of the most basic jobs a captain has.

"A pilot has certain responsibilities, and one of the most primary is maintaining a safe airspeed and altitude at all times. He may use automation to assist him, but it's his responsibility to ensure that technology is not leading him astray and is doing what he wants it to do."

Another aviation expert, Col. J.F. Joseph with Joseph Aviation Consulting, of Kyle¿, Texas, said it appears that the pilots were in "task overload.

"These airplanes are extremely complicated. If you don't understand what mode you're in, you're going to get a spanking -- Boeing, Airbus, whatever," he said.

Asiana said in its submission that the "highly trained and experienced" flight crew operating Flight 214 was beset by problems that "would have been difficult to predict."

It cited "inconsistencies in the aircraft's automation logic" that led to a disabling of systems to maintain a minimum airspeed "without warning to the flight crew," who believed the aircraft's auto-throttle system would maintain a safe airspeed through the final approach for landing.

Also, it said, a low airspeed alerting system "did not provide adequate time for recovery."

Finally, it said, "air traffic control instructions and procedures led to an excessive pilot workload during the final approach."

The airline noted that its pilots have flown into San Francisco "uneventfully for over 20 years" and knew how to land on visual approach.

The company "strongly encouraged" Boeing to change the 777's autothrottle so it would wake up when the aircraft deviates significantly from the desired speed.

It said the issue had been flagged by European aviation regulators and the lead FAA test pilot for the Boeing 787, which has essentially the same auto-throttle system.

Contact Pete Carey at 408-920-5419. Follow him on Twitter.com/petecarey.