Event CHI87IA109

Factual narrative

A UNITED AIRLINES BOEING 727 DOMESTIC PASSENGER FLIGHT WAS HOLDING SHORT OF RUNWAY 32L AT THE CHICAGO-O'HARE INTERNATIONAL AIRPORT AWAITING CLEARANCE FOR AN INTERSECTION TAKEOFF. A NORTHWEST AIRLINES BOEING 747 INTERNATIONAL PASSENGER FLIGHT WAS HOLDING IN POSITION AT THE END OF THE RUNWAY AWAITING TAKEOFF CLEARANCE. THE CONTROL TOWER CLEARED THE NORTHWEST FLIGHT FOR TAKEOFF AND THE CREW COMMENCED THE TAKEOFF ROLL. THE UNITED FLIGHT THOUGHT THEY HAD BEEN CLEARED FOR TAKEOFF AND TAXIED ONTO THE RUNWAY AND COMMENCE THEIR GROUND ROLL. THE TOWER CONTROLLER NOTED THE INCURSION AND INSTRUCTED THE NORTHWEST FLIGHT TO ABORT THE TAKEOFF. THE UNITED FLIGHT ALSO ABORTED THE TAKEOFF AND BOTH AIRCRAFT TAXIED OFF THE RUNWAY WITHOUT FURTHER INCIDENT. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12