Challenger 350 crosses an active runway at Chicago Midway, 2025

Preliminary reportRunway incursionTaxi

The short version

Flexjet 560 was cleared to taxi onto runway 4L, cross runway 31L and hold short of runway 31C. The crew did not recognise 31L as a runway and took 31C for it, so they crossed 31C while Southwest 2504 was on short final. The 737 went around and passed less than 200 ft behind the Challenger. The NTSB has not yet issued a final report or a probable cause.

What happened

  1. Before taxi, the crew call Midway ground from the Signature ramp. They say the reply does not make sense to them: a route to runway 22L via taxiway F, holding short of 4L. They ask for clarification and get a new route, taxiway A to taxiway F, holding short of runway 4L/22R.

  2. On taxiway F, ground clears them to turn left onto runway 4L, cross runway 31L and hold short of runway 31C. Their first readback is wrong. The controller repeats the instruction and gets a correct readback.

  3. Turning onto runway 4L/22R, the sun is in their eyes from the right. Neither pilot recalls seeing hold-short markings or signs for runway 31L. Taxiway F is close to runway 13R/31L, and by the time the nosewheel has straightened they are probably halfway across it. To them it looks as narrow as a taxiway. The captain later says that as he approached 13C/31C he thought it was 13R/31L.

  4. Approaching 31C, both pilots look left and right and do not see the 737. Ground instructs LXJ560 to hold short. The call is not acknowledged.

  5. Southwest 2504 is landing on runway 31C after an ILS approach in clear weather, autopilot off since about 500 ft. Both pilots had seen a general aviation aircraft taxiing on a surface across their runway and assumed it would hold short. At the 100 ft callout the first officer sees it is not stopping and calls a go-around. The captain flies it while the Challenger is crossing. The 737 passes less than 200 ft behind it.

  6. As they cross and leave 31C, ground tells LXJ560 to hold position. The captain keeps going until the tail is clear of the runway, then on instruction taxis clear of the runway safety area and holds short of taxiway H. Ground tells the crew they crossed 31C and gives them a number to call about a possible pilot deviation.

  7. About 5 minutes later they are cleared along runway 4L/22R and taxiway N to the north triangle. The captain sets the parking brake, hands control to the first officer, calls the tower and the operator, and checks that both pilots are fit to continue. They depart about 25 minutes after the incursion. Southwest 2504 lands a few minutes after its go-around.

The time is local (central standard time) and approximate. The preliminary report gives no clock times for the other entries.

The weather was clear, wind from the northwest at 8 kt, visibility better than 10 statute miles. The sun was 22.4° above the horizon. Seen from the intersection of runway 4L/22R and runway 13C/31C, it stood at an azimuth of 126°. The airport supplied photos of the runway 13C/31C hold-short line and of the red runway signs on either side of the hold-short markings.1

The cockpit voice recorders on both aircraft had been overwritten. Flight data from both aircraft went to the NTSB recorder laboratory.1

Why it happened

  1. The NTSB has not yet published a final report or a probable cause. The preliminary report gives the facts collected so far and the crews' own accounts. It makes no findings and no recommendations.1

  2. The NTSB set up groups for operations, vehicle performance, human performance, airport operations, air traffic control and flight data recorders.

  3. It interviewed the Flexjet crew and chief pilot on 4 March 2025 and the Southwest crew on 13 March 2025. The FAA supplied certified ADS-B data and the ATC audio. The Transportation Safety Board of Canada appointed an accredited representative, with Bombardier as technical adviser.

What a crew can take from it

  1. Settle the taxi route before the aircraft moves. The first clearance made no sense to the crew, and their first readback of the second one was wrong. When that happens, stop, write the route down and trace it on the airport diagram together. Name every runway you will cross and the one you stop short of.

  2. Count the runways as you pass them. The crew were cleared to cross one runway and stop at the next. By their own account they did not recognise 31L as a runway, and the captain took 31C for the runway they had been cleared to cross. Tick off each runway by its signs, markings and the chart, and say it aloud.

  3. A narrow strip of pavement can still be a runway. The crew said 31L looked like a taxiway and came up right after the turn off taxiway F. Look for the red runway signs and the hold-short markings at every crossing.

  4. Low sun can hide what you need to see. With the sun low on the right, the crew did not recall the signs or markings at the first runway. From the 31C crossing the sun stood at 126°, roughly where the final approach to runway 31C lies. Expect glare on an early morning taxi and share the lookout between both pilots.

  5. If ground calls you near a runway, stop and answer. The hold-short call came as the jet approached 31C, and nobody answered it. A call you missed, or one you cannot make sense of, means stop at the line and ask. The 737 crew also assumed the jet would stop. Nobody outside your cockpit can see what you have understood.

Study it on the course

Sources

  1. National Transportation Safety Board. Aviation Investigation Preliminary Report DCA25LA141, Boeing 737-800 N8517F and Bombardier BD-100-1A10 (CL-35) N560FX, Chicago, Illinois, 25 February 2025.
  2. AVweb, NTSB Issues Preliminary Report On Midway Near-Collision, 19 March 2025.
  3. AeroTime, Flexjet pilot unsure of runways before Southwest's go-around, 19 March 2025.

Last updated 22 October 2026

For study only. Always use the approved AFM, QRH and operator procedures.