No fatalities

727 Destroyed in Runway Excursion After Takeoff Warning Ignored (N7425U)

Chicago-O'Hare, United States of AmericaTakeoff (climb)

On March 21, 1968, a Boeing 727-100 (registration N7425U) operated by United Airlines was involved in an aviation accident near Chicago-O'Hare, United States of America during takeoff. No fatalities were reported. Investigators recorded the probable cause as: The failure of the crew to abort the takeoff after being warned of an unsafe takeoff condition. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 10 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary report: the U.S. National Transportation Safety Board (NTSB) historical archive (1962-1981)Updated 2026-07-04Data APIEditorial standards
Boeing 727-100
Photo: Pete Macklin / CC BY-SA 2.0, via Wikimedia Commons

A Boeing 727 crashed after takeoff from runway 09R when the crew continued despite a takeoff warning horn. The aircraft overran the runway, struck a ditch, and was destroyed by fire. All three crew members were injured.

Accident Sequence

Shortly after beginning the takeoff roll on runway 09R, the takeoff warning horn sounded. The crew continued the takeoff while attempting to identify the cause of the warning. The horn ceased before the aircraft reached rotation speed. Subsequently, the stick shaker activated, and the flight crew increased thrust. However, the aircraft failed to climb. The captain then elected to discontinue the takeoff. The 727 settled onto the macadam shoulder to the right of the runway, struck a ditch, and came to rest 1,100 feet beyond the departure end of the runway and 300 feet to the right of the extended centerline.

Damage and Injuries

The aircraft was destroyed by a post-crash fire. All three crew members were injured.

Aircraft Configuration

Investigation determined that the flaps were set at 2 degrees, whereas the certified takeoff flap range is 5 to 25 degrees.

Probable Cause

The official finding attributed the accident to the crew's failure to abort the takeoff after being warned of an unsafe takeoff condition.

All Boeing 727-200 accidents →

Frequently asked questions

What happened in the 21 Mar 1968 Boeing 727-100 accident near Chicago-O'Hare, United States of America?

A Boeing 727 crashed after takeoff from runway 09R when the crew continued despite a takeoff warning horn. The aircraft overran the runway, struck a ditch, and was destroyed by fire. All three crew members were injured.

Were there any fatalities in the 21 Mar 1968 Boeing 727-100 accident?

No fatalities were recorded in this accident.

What aircraft was involved and where did it happen?

The accident on 21 Mar 1968 involved a Boeing 727-100, registration N7425U, operated by United Airlines, at Chicago-O'Hare, United States of America.

What was the probable cause of the accident?

The failure of the crew to abort the takeoff after being warned of an unsafe takeoff condition.