United Airlines Flight 585
N999UA, the aircraft involved in the accident, pictured in 1989 | |
| Accident | |
|---|---|
| Date | March 3, 1991 |
| Summary | Rudder hardover and loss of control due to design flaw |
| Site | |
| Total fatalities | 25 |
| Total injuries | 1 |
| Aircraft | |
| Aircraft type | Boeing 737-291 |
| Operator | United Airlines |
| IATA flight No. | UA585 |
| ICAO flight No. | UAL585 |
| Call sign | UNITED 585 |
| Registration | N999UA |
| Flight origin | Greater Peoria Regional Airport |
| Stopover | Quad Cities International Airport |
| Last stopover | Stapleton International Airport |
| Destination | Colorado Springs Municipal Airport |
| Occupants | 25 |
| Passengers | 20 |
| Crew | 5 |
| Fatalities | 25 |
| Survivors | 0 |
| Ground casualties | |
| Ground injuries | 1 |
United Airlines Flight 585 was a scheduled passenger flight on March 3, 1991, from Denver to Colorado Springs, Colorado, carrying 20 passengers and 5 crew members. The Boeing 737 experienced a rudder hardover while on final approach to runway 35 at Colorado Springs Municipal Airport, causing the plane to roll over and enter an uncontrolled dive. All on board were killed on impact.
The National Transportation Safety Board (NTSB) was initially unable to resolve the cause of the crash, but after similar accidents and incidents involving Boeing 737 aircraft, including the fatal crash of USAir Flight 427, the crash was determined to be caused by a defect in the design of the 737's rudder power control unit which caused the rudder to work in the opposite direction.