The US National Transportation Safety Board (NTSB) is investigating a serious runway incursion between a Southwest Boeing 737-700 and an Empire Airways Cessna Caravan at the Phoenix Sky Harbor International airport just before dusk on 19 March.
According to the NTSB's preliminary report issued earlier this week, Empire flight 7775 was cleared to land on runway 25L at Phoenix but just before landing, diverted and landed on the parallel runway 25R, located roughly one-half mile north and east of 25L.
The pilots of Southwest flight 1063, which had just been cleared for take off on runway 25R, saw the Caravan overflying their aircraft and halted their departure, says the NTSB. The pilots estimated that the Caravan came within 50ft (15m) of the 737.
NTSB says the sun was setting at the time of the incident, with otherwise good weather, and that the airport's surface detection system Model-X (ASDE-X) did not issue an alert.