Allen: How many weeks' holiday a year are there? ciprofloxacin buy Federal crash Investigators previously said that pilots recognized they were too low and not lined up precisely with the runway while still 500 feet from the ground. At 500 feet, pilots recognized that they were low as the Boeing 777 was going 134 knots and was 34 seconds from impact. They continued to make adjustments until hitting the seawall at the end of the runway at San Francisco International Airport.