1972 Chicago–O'Hare runway collision

Delta Air Lines Flight 954 was a regularly scheduled flight from Tampa, Florida, to O'Hare International Airport, Chicago, Illinois. The crew consisted of Captain Robert E. McDowell (36), First Officer Harry D. Greenberg (31), and Flight Engineer Claude F. Fletcher (29), as well as four flight attendants. Operating Convair CV-880 N8807E, it departed Tampa at 3:41 p.m. EST on December 20, 1972, and made a routine flight to Chicago, where it landed on Runway 14L at O'Hare International Airport at 5:55 or 5:56 p.m. CST. During their approach, the flight crew was informed that Runways 14L and 14R were being used for departures, but were never told that Runway 27L also was being used for departures.[1]^{: 3, 15–16}

Conditions at the airport were foggy, with a visibility of about one-quarter mile (0.4 km). Upon clearing Runway 14L, Flight 954 began taxiing southwest and south toward the terminal, leaving Runway 14L by way of the Bridge Route taxiway. It had already crossed the north–south bridge that carries the taxiway from Runway 14L to the terminal by the time the first officer contacted O'Hare ground control and reported that the aircraft was "inside [i.e., south of] the bridge", had not yet received a gate assignment, and needed to wait in a holding area until receiving an assignment.

The ground controller did not hear the words "inside the bridge," and, assuming Flight 954 had just left the end of Runway 14L and was still well north of the bridge, ambiguously instructed it to hold in the "thirty-two box", meaning in the controller's mind the 32R run-up pad at the southeast end of Runway 14L, where he assumed the plane to be. To reach the 32R run-up pad, Flight 954 would have had to turn around and return to the end of Runway 14L, where it had just landed, taxiing against the flow of traffic; instead, Flight 954's captain and first officer both assumed that the ground controller understood that they were "inside the bridge" and was referring to the 32L run-up pad, which was located at the southeast end of Runway 14R, on the other side of the terminal from the 32R run-up pad.[7] Assuming that they were cleared to taxi to the 32L pad, they proceeded toward it using the Bridge, Outer Circular, and North–South taxiways, via a route that intersected with Runway 27L.[1]^{: 2–3, 16}

There was no further communication between Flight 954 and the ground controller. This left the ground controller with the assumption that Flight 954 was holding at the 32R run-up pad and in no danger of conflicting with other traffic and the flight crew with the assumption that they were cleared to taxi to the 32L run-up pad and could cross Runway 27L without danger of a collision with aircraft using that runway. Moreover, Flight 954's flight crew had never received word that Runway 27L was an active runway, and had no reason to anticipate encountering other aircraft while taxiing across it.[1]^: 2–3

North Central Airlines Flight 575 was a regularly scheduled flight originating at O'Hare International Airport and stopping at Madison, Wisconsin, before terminating at Duluth, Minnesota. It was flown by Captain Ordell T. Nordseth (49) and First Officer Gerald Dale Adamson (32). Operating McDonnell Douglas DC-9-31 N954N, the flight received clearance from O'Hare ground control at 5:50 p.m. CST to taxi to Runway 27L for departure. At 5:58:52.3 p.m. CST the O'Hare local controller cleared Flight 575 into takeoff position on the runway and at 5:59:18 p.m. CST cleared it for takeoff. At 5:59:24.3 p.m. CST, the captain reported that he was beginning his takeoff roll.[1]^: 3

Immediately after the collision, the captain of Flight 954 received reports of a fire aboard the CV-880; he shut down the engines and ordered an immediate emergency evacuation. The crew opened the four emergency doors and deployed the emergency slides, and all aboard the plane were successfully evacuated in about five minutes without further incident.[1]^: 8

After the DC-9 came to rest on Runway 32L, a fire broke out in the aft part of the plane, the cabin rapidly filled with smoke, and interior illumination in the passenger cabin was poor. The captain pulled the fire extinguisher handles and ordered an emergency evacuation. One passenger opened the right overwing door and escaped that way. One flight attendant opened the left overwing exit, exited the aircraft, and called on passengers to follow her; four passengers escaped via this door. The other flight attendant opened the main entry door and deployed the emergency slide, which did not inflate; she then was pushed out the door, but assisted passengers off the plane from outside the doorway. The captain entered the passenger cabin from the cockpit, calling passengers to come forward, then exited the plane via the main entry door and helped them to the ground before reboarding to assist more passengers off through the main door. The first officer escaped through a cockpit window and assisted passengers out of the aircraft from outside the plane at the main entry door. A total of 27 passengers exited via the main entry door.[1]^: 11

Two people aboard the Delta CV-880 suffered minor injuries in the collision, but all 93 people aboard evacuated the aircraft without further injury.[1]^: 10

A total of 10 people, all passengers, died aboard the North Central DC-9. Nine of the fatalities occurred in the post-collision fire among people who were unable to evacuate; the tenth person died later. Fifteen people aboard Flight 575 suffered non-fatal injuries.[1]^: 11