Some aviation accidents seem inexplicable. How could a Boeing 727 collide with a Cessna 172, both flown by experienced crews, in excellent visibility, on approach to an airport with apparently good ATC and even a collision alert system? Stephen Skinner investigates
San Diego residents going about their normal business on the morning of September 25, 1978, could not have expected that a Boeing 727 and a Cessna 172 were going to crash on them.
Both aircraft collided and crashed killing all on board totalling 144, along with seven people on the ground.
As a result of this disastrous accident and others, airliners and cargo aircraft heavier than 12,600lb are all now fitted with Traffic Collision Avoidance Systems (TCAS) which help aircraft evade collision.