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| Title: | Runway excursion, United Air Lines, Inc., Boeing 727 QC, N7425U, Chicago O'Hare International Airport, Illinois, March 21, 1968 |
| Micro summary: | This Boeing 727 QC abandoned its takeoff after rotation, resulting in a runway excursion. |
| Event Time: | 1968-03-21 at 0351 CST |
| File Name: | 1968-03-21-US.pdf |
| Publishing Agency: | National Transportation Safety Board (NTSB) |
| Publishing Country: | USA |
| Report number: | NTSB-AAR-1968-12-31 |
| Pages: | 61 |
| Site of event: | ORD |
| Departure: | Chicago O'Hare International Airport, Chicago, Illinois, USA |
| Destination: | Seattle-Tacoma International Airport, Seattle, Washington, USA |
| Airplane Type(s): | Boeing 727 QC |
| Flight Phase: | Takeoff |
| Registration(s): | N7425U |
| Operator(s): | United Airlines |
| Type of flight: | Revenue |
| Occupants: | 3 |
| Fatalities: | 0 |
| Serious Injuries: | 3 |
| Minor/Non-Injured: | 0 |
| Other Injuries: | 0 |
| Executive Summary: | A United Air Lines, Inc., Boeing 727 QC, N7425U, operating as Cargo Flight 9963, crashed on takeoff from O'Hare International Airport, Chicago, Illinois, on March 21, 1968, at approximately 0353 CST The aircraft was destroyed by impact and ground fire. The three crewmembers, who were the only occupants of the aircraft, evacuated through the cockpit windows. The captain sustained injuries requiring hospitalization, while the first and second officers received only minor injuries. Shortly after commencement of the takeoff roll on Runway 9R, the intermittent takeoff warning horn sounded, indicating an improper setting for takeoff of any one or a combination of the following items: flaps, speed brakes, stabilizer trim, or auxiliary power unit exhaust door. As the takeoff progressed, the crew attempted unsuccessfully to locate the condition which initiated the warning horn. The horn finally ceased just prior to reaching rotate speed. Almost immediately after the captain rotated the aircraft, the stick shaker came on, indicating the aircraft was approaching a stall. The captain lowered the nose slightly and added thrust, but the aircraft failed to climb or accelerate. The captain therefore elected to discontinue the takeoff and allowed the aircraft to settle back to the macadam shoulder off the right side of the runway. The aircraft then proceeded across the ground at an angle of approximately 4° with the runway until it-came to rest at a point 1,100 feet beyond the east end of Runway 9R and 300 feet to the right of its centerline. During the latter part of the rollout, the aircraft struck a drainage ditch, causing damage which resulted in the fuel fed ground fire which consumed much of the aircraft. Evidence in the wreckage established that the flaps were set at the 2° position. This setting is outside the takeoff range of 5° to 25° and thus constitutes a condition which would activate the warning horn. The Safety Board determines that the probable cause of this accident was the failure of the crew to abort the takeoff after being warned of an unsafe takeoff condition. |
| Learning Keywords: | Operations - Evacuation |
| Operations - Rejected Takeoff after V1 | |
| Operations - Runway Overrun | |
| Systems - Flight Controls - Flap Configuration | |
| Consequence - Hull Loss |
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