Eastwind Airlines Flight 517
N221US, the aircraft involved in the incident, seen at Tampa International Airport in 1998, two years after the incident.
|Date||June 9, 1996|
|Site||Richmond International Airport, Richmond, Virginia, United States|
|Aircraft type||Boeing 737-2H5|
|Flight origin||Trenton-Mercer Airport|
|Destination||Richmond International Airport|
On June 9, 1996, while operating a passenger flight from Trenton, New Jersey to Richmond, Virginia, the crew of Eastwind Airlines Flight 517 temporarily lost control of their Boeing 737-200 due to a rudder malfunction. The crew were able to regain control and landed the aircraft successfully. One person aboard was injured.
Flight 517 was instrumental in resolving the cause of Boeing 737 rudder issues that had previously caused two fatal crashes. Flight 517 was the first flight to experience such rudder issues and land safely, allowing investigators to interview the pilots about their experience and to study the aircraft.
On March 3, 1991, United Airlines Flight 585, a Boeing 737-200, rolled to the right and went into a vertical dive while attempting to land in Colorado Springs, Colorado. The resulting crash killed all 25 people on board. The National Transportation Safety Board (NTSB) conducted a thorough investigation. Although a rudder problem was suspected, the aircraft's rudder components could not be tested or fully evaluated because they were too badly damaged in the crash. As a result, the NTSB was unable to conclusively identify the cause of the crash.:47
On September 8, 1994, USAir Flight 427, a Boeing 737-300, abruptly rolled to the left while on approach to Pittsburgh International Airport in an accident very similar to Flight 585. The resulting crash killed all 132 people on board.:1 The NTSB commenced an investigation into Flight 427, which was ongoing throughout the late 1990s.
Flight 517 was a scheduled Eastwind Airlines passenger flight from Trenton-Mercer Airport in Trenton, New Jersey, to Richmond International Airport in Richmond, Virginia. The flight was operated using a Boeing 737-200 (registration number N221US). On June 9, 1996, Flight 517 was operated by captain Brian Bishop and first officer Spencer Griffin. A total of 53 people were on board.:51
Flight 517 departed Trenton without incident and encountered no turbulence or unusual weather en route to Richmond. While on approach to Richmond International Airport, at an altitude of about 5,000 feet (1,500 m) MSL, the captain felt a brief "kick" or "bump" on the right rudder pedal.:51 Around the same time, a flight attendant at the rear of the plane heard a thumping noise underneath her.:52 As the plane continued to descend through 4,000 feet (1,200 m), the captain suddenly experienced a loss of rudder control and the plane rolled sharply to the right.:51
Attempting to regain control, the captain tried to apply full left rudder, but the rudder controls were stiff and did not respond to his commands. The captain applied left aileron and increased power to the right engine to try to stop the roll. The airplane temporarily stabilized, and then rolled to the right again. The crew performed their emergency checklist and attempted to regain control of the aircraft, and after several seconds they abruptly regained control. The airplane operated normally for the duration of the flight.:51–52
No damage occurred to the aircraft as a result of the incident. One flight attendant suffered minor injuries. No other passengers or crew aboard Flight 517 were injured.
Investigation and aftermath
The NTSB investigated the incident, with a particular focus on determining if the events of Flight 517 were related to prior Boeing 737 crashes.:44
During its investigation, the NTSB determined that prior to Flight 517, flight crews had reported a series of rudder-related events on the incident aircraft, including uncommanded "bumps" on the rudder pedals and uncommanded movement of the rudder.:263
Investigators removed rudder components from the incident aircraft, which combined with interviews with the pilots of Flight 517, helped investigators establish the cause of the prior crashes United Flight 585 and USAir Flight 427. The NTSB determined that all three incidents could only be explained by pilot error or a malfunction of the rudder system, and based partly on post-accident interviews with the Flight 517 pilots, determined it was likely that rudder malfunctions had caused all three incidents.:272–73
The NTSB also determined that, unlike the United or USAir accidents, the rudder problem on Flight 517 occurred earlier in the landing process and at a higher speed, which increased airflow over the aircraft's other control surfaces and allowed the pilots to overcome the rudder-induced roll.:269
- Aircraft Accident Report - Uncontrolled Descent and Collision With Terrain, USAir Flight 427, Boeing 737-300, N513AU, Near Aliquippa, Pennsylvania, September 8, 1994 (PDF). National Transportation Safety Board. March 24, 1999. NTSB/AAR-99-01. Retrieved July 10, 2016.