(San Francisco, CA)    --  The NTSB says it appears the Asiana Boeing 777 that crashed in San Francisco came in too slow.  NTSB Chairwoman Deborah Hersman says according to the Flight Data Recorder, one of the pilots called for increased speed just seven seconds prior to impact.  There was a separate call by one of the pilots for a "go around" meaning another landing attempt.  Two people were killed and dozens of others injured among the 307 people on board the flight from South Korea.