What happened
During an approach to runway 27R at Philadelphia International Airport, Pennsylvania, an Allegheny Airlines Douglas DC-9-31 encountered heavy precipitation as a thunderstorm moved across the airfield. While performing an instrument approach under visual conditions, the pilot decided to execute a go-around near the runway threshold due to increasing rainfall intensity.
Following the decision to climb, the aircraft began a descent while maintaining a nose-up pitch with the landing gear retracted. The plane subsequently struck a taxiway approximately 4,000 feet past the runway threshold. The impact occurred tail-first, causing the aircraft to slide for an additional 2,000 feet. The wreckage eventually stopped roughly 6,000 feet beyond the threshold, positioned about 350 feet to the right of the runway centerline. There were no fatalities among the 106 people on board, though the accident resulted in 86 injuries.
Findings
Investigations determined that the primary factor was the aircraft's encounter with severe horizontal and vertical wind shear near the ground. This occurred because the approach was continued into weather conditions that were clearly marginal. While the aircraft could have potentially overcome the shear if maximum aerodynamic and engine power had been applied, the conditions exceeded the standard operational margin. Additionally, the air traffic controller failed to relay updated visibility information regarding the runway visual range (RVR) in a timely manner.