( CNN ) -- Pilots botched the approach and landing of Asiana Airlines Flight 214 in San Francisco nearly a year ago , causing a crash that killed three people and injured 187 others , U.S. safety investigators concluded on Tuesday . But the National Transportation Safety Board also found that crew training and the complexities of a key flight system on the Boeing 777 and how it was described in operating manuals contributed to the July 6 disaster . Investigators , however , primarily faulted the crew of the Korean-based carrier for not fully executing intricate systems of the jetliner packed with more than 300 people before it struck a seawall and careened down Runway 28L trailing sparks and debris . Read the NTSB 's accident report summary . In a final report on its probe , the board found that the flight crew mismanaged the plane 's descent being carried out without the help of navigational instruments and one of the pilots unintentionally deactivated a system that automatically regulates airspeed . The crew also delayed its decision to abort the landing with the plane flying too slowly to avoid catastrophe , investigators found . The final conclusion was largely in line with early assumptions of investigators facing the most serious commercial airline crash in the United States since a Colgan Air commuter plane fell out of the sky over Buffalo , killing 49 people in February 2009 . Crew actions were also singled out in that accident . Aviation experts agree that aircraft automation has made flying safer , and the 777 is one of the most sophisticated jetliners in service . `` But the more complex automation becomes , the more challenging it is to ensure that the pilots adequately understand it , '' Christopher Hart , the acting safety board chairman said in a statement . `` In this instance , the flight crew over-relied on automated systems that they did not fully understand . As a result , they flew the aircraft too low and too slow and collided with the seawall at the end of the runway . '' Asiana Airlines fined $ 500,000 for failing to help families . Asiana crash victims sue Boeing .
The National Transportation Safety Board released its final report on the 2013 crash . Investigators said errors by the cockpit crew caused the crash in San Francisco . The Boeing 777 crashed short of the runway ; 21 people were killed , 187 hurt .