The National Transportation Safety Board (NTSB) determined that the probable cause was that the aircraft's rudder malfunctioned and went hard over in a direction opposite to that commanded by the pilots, causing the plane to enter an aerodynamic stall from which Captain Peter Germano and First Officer Charles B. Emmet III were unable to recover.

Flight 427 was operating under the provisions of 14 Code of Federal Regulations Part 121 as a scheduled domestic passenger flight from Chicago-O'Hare International Airport, Chicago, Illinois, to Pittsburgh. The flight departed about 1810, with 2 pilots, 3 flight attendants, and 127 passengers on board.

Abstract: This report explains the accident involving USAir flight 427, a Boeing 737-300, which entered an uncontrolled descent and impacted terrain near Aliquippa, Pennsylvania, on September 8, 1994.

National Transportation Safety Board

This information was developed in the course of the Board’s investigation of the September 8, 1994, USAir flight 427 accident, which included an investigation of the June 9, 1996, incident involving Eastwind Airlines flight 5172 and a reexamination of …

USAir Flight 427, a Boeing 737-300, crashed following a loss of control during the approach to Pittsburgh International Airport, Pennsylvania, USA. All 132 on board were killed. The flight departed Chicago-O'Hare International Airport, Illinois at 18:10 hours on a flight to Pittsburgh.

The upsets of USAir flight 427, United flight 585, and Eastwind flight 517 were most likely caused by the movement of the rudder surfaces to their blowdown limits in a direction opposite to that commanded by the pilots.

USAir Flight 427 crashed while on approach to Pittsburgh International Airport following a loss of control and airplane stall precipitated by an encounter with the wake of a preceding Boeing Model 727 airplane.

On September 8, 1994, USAir Flight 427, a Boeing 737-300, crashed while maneuvering to land at Pittsburgh International Airport. The airplane was being operated on an instrument flight plan under 14 CFR Part 121 on a regularly scheduled flight from Chicago, Illinois.

After USAir Flight 427, a Boeing 737-300, crashed outside Pittsburgh on September 8, 1994, St. Petersburg Times reporter Bill Adair was granted unprecedented access to the National...