Analysis of air-ground communications at Chicago Midway airport indicates that an executive jet failed to comply with a hold-short instruction before crossing an active runway, on which a Southwest Airlines Boeing 737-800 was nearing touching down.
The 737 crew initiated a go-around and overflew the Flexjet Bombardier Challenger 350 on 25 February.
According to air-ground transmissions at the time of the incursion, the 737 had been cleared to land on runway 31C.
The Challenger – previously cleared to the intersection of taxiway F and runway 4L/22R – had subsequently been instructed to turn left onto 4L, cross the runway 31L, and hold short of 31C.
Its crew initially gave a confused reply, prompting a correction from the tower that reiterated the directions.
The Challenger crew replied confirming the instruction to cross 31L then hold short of 31C.
Runway 31L is a short, narrow runway which lies just 50m from the point where the Challenger turned onto 4L.
Video images from a live feed of Midway arrivals indicate the Challenger continued travelling along 4L, beyond the 31C hold-short point, taxiing across the runway in front of the 737 which was about to touch down.
The 737 crew carried out a go-around, and one of the pilots asked a tower controller: “How’d that happen?”
According to the communications exchange, which was archived by LiveATC, the ground controller told the Challenger crew: “Your instructions were to hold short of runway 31C.”
Good visibility prevailed at the time.
Runway 31C intersects with 4L about 1,000m from the 31C threshold. The distance between the two aircraft at the point when the Challenger cross the runway has yet to be confirmed.
