Greater Southwest International Airport, located between Dallas and Fort Worth, Texas, was to be the site of two training flights on the morning of May 30, 1972. Just after 5:00am, an American Airlines DC-10 took off from Love Field, arriving at Greater Southwest shortly afterwards, where it began a series of touch-and-goes. An hour and a half later, Delta N3305L, a DC-9, departed Love Field for Greater Southwest, requesting practice approaches. On board the aircraft was a Delta check pilot, two First Officers undergoing command training, and an FAA inspector.

The American aircraft had been using runway 13 and N3305L was cleared for an ILS approach behind it. After landing, the aircraft taxied back to the threshold of runway 13, requesting another ILS approach. After making it's approach, again behind the American aircraft, N3305L executed a missed approach and asked for a VOR approach to runway 35. After beginning the approach, the crew asked for a missed approach to be followed by a circle-to-land approach at low level to runway 17. As the crew entered a downwind for 17, it realized a possible conflict with the American aircraft landing on runway 13, so they asked to land on runway 13 behind the DC-10 instead of 17.

The Tower replied "OK. That'll be fine...use runway 13 for a full stop. Caution...wake turbulence." The last part was required practice whenever an aircraft approaches behind a heavy jet with less than 2,500ft separating the two. However, the aircraft never got closer than two miles. N3305L was just turning on final when the DC-10 touched down. Delta's aircraft was configured for landing and stabilized on approach until just a few seconds before landing when it's port wing dropped. This was apparently over-corrected by the crew as the right wing then dropped followed by another roll to the left.

Then, just as the aircraft crossed the threshold, at an altitude of about 50ft, the right wing dropped sharply and impacted the runway as the aircraft rolled through vertical. The aircraft fell to the runway on it's back, exploding as it slid some 2,000ft until coming to rest. All four of the occupants were killed.
......It seemed clear that the only explanation for the accident was wake turbulence, though it was previously thought that it only affected small aircraft. Analysis of both aircraft's flight path's showed that N3305L would have passed through the DC-10's flight path, approaching it's wake vortices at approximately 60 feet just less than a minute after the DC-10 touched down. Meteorological conditions at the time would have been conducive to the wake vortices staying in the threshold zone for more than two minutes. Recovery of the aircraft's recorders showed that it encountered a gust registering 1.7gs during which the check captain was heard to say "A little turbulence here!" As the encounter continued, the captain then said "Let's go round" followed by "Takeoff power!"

The aircraft then encountered a gust of -1g as the aircraft rolled onto it's back. Study of the physics of the wake vortices showed that even full aileron deflection could not have overcome the tremendous roll rate created by the DC-10's wake. This accident prompted the FAA to instate new separation standards for wake turbulence avoidance.