Incident | |
---|---|
Date | October 9, 2002 |
Summary | Rudder hardover due to metal fatigue |
Site | Bering Sea |
Aircraft | |
Aircraft type | Boeing 747-451 [a] |
Operator | Northwest Airlines |
IATA flight No. | NW85 |
ICAO flight No. | NWA85 |
Call sign | NORTHWEST 85 |
Registration | N661US [1] |
Flight origin | Detroit Metropolitan Wayne County Airport, Detroit, Michigan, United States |
Destination | Tokyo Narita Airport, Narita, Chiba, Japan |
Occupants | 404 |
Passengers | 386 |
Crew | 18 |
Fatalities | 0 |
Injuries | 0 |
Survivors | 404 |
Northwest Airlines Flight 85 was a scheduled international passenger flight from Detroit Metropolitan Wayne County Airport in the United States to Narita International Airport in Japan. On October 9, 2002, while over the Bering Sea, the Boeing 747-400 experienced a lower rudder hardover event, which occurs when an aircraft's rudder deflects to its travel limit without crew input. The 747's hardover gave full left lower rudder, requiring the pilots to use full right upper rudder and right aileron to maintain attitude and course.
The flight diverted to Ted Stevens Anchorage International Airport. No passengers or crew were injured, but the incident resulted in an airworthiness directive to prevent the possibility of a future accident.
The aircraft involved was the prototype Boeing 747-400 (Boeing 747-451, c/n 23719, reg N661US) and was built by Boeing, and started the flight testing program for the new model, registered as N401PW, in April 1988. It was subsequently reregistered as N661US and delivered to Northwest Airlines (the launch customer for the 747-400) on December 8, 1989. The aircraft was later delivered to Delta Air Lines on October 29, 2008. After a further seven years in service with Delta, N661US was retired in 2015, and was then sent to the Delta Flight Museum for preservation on April 30, 2016. [2] [3]
The flight departed Detroit Metropolitan Wayne County Airport at 2:30 p.m. Eastern Daylight Time. The incident occurred at 5:40 p.m. Alaska Daylight Time, around seven hours into the flight. [4] At the time of the incident, Junior Captain Frank Geib and First Officer Mike Fagan had just taken control of the aircraft, allowing Senior Captain John Hanson and First Officer David Smith to rest. [5] Flight 85's captain said that the event occurred at FL350 (35,000 feet/11,000 meters). [1]
The aircraft abruptly entered a 30- to 40-degree left bank. [1] Geib initially believed that an engine failure had occurred. Hanson reentered the cockpit and continued to fly the aircraft by hand with Fagan. Geib declared an emergency and began a diversion to Anchorage. [5] While the crew tried to declare the emergency, the plane was in a communications dead zone between North America and Asia. Even with a weak signal, the crew contacted another Northwest Airlines flight, Flight 19, which helped Flight 85 declare the emergency as it was closer to Alaska. [6] Flight 85's captain reported that none of the emergency procedures available could correct the problem. [1] The pilots established a conference call with Northwest Airlines in the Minneapolis-St. Paul area, but the employees there were unable to find a solution to the sudden bank. [5] The flight crew took back control of the aircraft and landed at Ted Stevens Anchorage International Airport. To steer the aircraft, they had to use the ailerons and asymmetric engine thrust, applying more engine power to one side than the other. [4]
Hanson said that crew resource management (CRM) contributed to the flight's safe landing at Anchorage:
This was a classic application of CRM. We were blessed and lucky that we had full flight crew augmentation. We had four pilots to work together in the cockpit. We had an excellent group of flight attendants on board; that became important later because we briefed this as a 'red' emergency, which means there's at least a solid chance you're going to have to evacuate. We weren't sure we were going to be able to keep the airplane on the runway.
— John Hanson, Senior Captain of Northwest Airlines Flight 85 [5]
The incident did not initially receive media attention. [4]
The National Transportation Safety Board (NTSB) and Boeing launched investigations into the incident. [4] NTSB investigator Carolyn Deforge, who oversaw the investigation, recounted in an interview on the television program Mayday : "It appeared to be a very dramatic event, and ... it definitively seemed like something we needed to follow up on, trying to understand what had happened." [6]
The NTSB found that there was a fatigue crack in the power control module and that it was not possible to visually inspect that type of failure. [1] The lower rudder control module's cast metal housing had broken. The end portion of the control module housing that housed the yaw damper actuator had separated from the main portion of the housing. [4] Deforge said in the Mayday episode that the NW85 failure was unusual because most failures are of internal components rather than of the housing itself. [6]
The NTSB ruled that the probable cause was a "fatigue fracture of the lower rudder power control module manifold, which resulted in a lower rudder hardover." [1] In a rudder hardover, the rudder is driven to its full deflection and stays there. [7]
A non-destructive inspection process for the module was developed. As a result, Boeing issued Alert Service Bulletin 747-27A2397. The bulletin, dated July 24, 2003, recommended that Boeing 747 operators conduct ultrasonic inspections of pertinent high-time lower and upper rudder power control modules. [1] : 4
The Federal Aviation Administration published a Notice of Proposed Rule Making for an airworthiness directive that would make ultrasonic inspections mandatory on Boeing 747-400, 400D and 400F aircraft. The "Airworthiness Directive; Boeing Model 747-400, -400D, and -400F Series Airplanes" was published in the federal register on August 28, 2003. [1] : 4 The directive, labeled Directive 2003-23-01, [9] was issued on November 3, 2003 and became effective December 18, 2003. [10] It has since been superseded by directive 2006-18-17, [11] issued August 30, 2006 and effective October 13, 2006. [12] In 2008, a proposed replacement to this directive was published. [13] [14]
N661US was not damaged during the incident and it was returned to service with Northwest Airlines. [15]
By January 2004, the Air Line Pilots Association awarded the "Superior Airmanship Award" to the crew of Northwest 85. [5]
On February 24, 2009, the aircraft involved in the incident, along with the other 747-400s in Northwest Airlines' fleet, joined the Delta Air Lines fleet as part of the Northwest-Delta Air Lines merger. On September 8, 2015, it left Honolulu, Hawaii for its final flight and was retired on arrival at Atlanta, Georgia's Hartsfield–Jackson Atlanta International Airport. It was transferred to the adjacent Delta Flight Museum for public display at the end of April 2016. [16] [17] [18] [19] After being moved to its current position, a special permanent exhibit called the 747 Experience was constructed alongside the aircraft, and was formally opened on March 28, 2017. [20] [21]
The Discovery Channel Canada / National Geographic TV series Mayday featured the incident in a Season 11 episode titled Turning Point. [6]
Atlas Air, Inc. is a major American cargo airline, passenger charter airline, and aircraft lessor based in White Plains, New York. It is a wholly owned subsidiary of Atlas Air Worldwide Holdings. Atlas Air is the world's largest operator of the Boeing 747, with 54 of the type. In 2021, the airline had 4,056 employees and operated to more than 300 global destinations.
The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The "Advanced Series 300" was announced at the September 1984 Farnborough Airshow, targeting a 10% cost reduction with more efficient engines and 1,000 nautical miles [nmi] of additional range. Northwest Airlines became the first customer with an order for 10 aircraft on October 22, 1985. The first 747-400 was rolled out on January 26, 1988, and made its maiden flight on April 29, 1988. Type certification was received on January 9, 1989, and it entered service with Northwest on February 9, 1989.
The Pratt & Whitney PW4000 is a family of dual-spool, axial-flow, high-bypass turbofan aircraft engines produced by Pratt & Whitney as the successor to the JT9D. It was first run in April 1984, was FAA certified in July 1986, and was introduced in June 1987. With thrust ranging from 50,000 to 99,040 lbf, it is used on many wide-body aircraft.
SilkAir Flight 185 was a scheduled international passenger flight operated by a Boeing 737-300 from Soekarno–Hatta International Airport in Jakarta, Indonesia to Changi Airport in Singapore that crashed into the Musi River near Palembang, Sumatra, on 19 December 1997, killing all 97 passengers and 7 crew members on board.
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 on board. The plane 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 25 people on board the Boeing 737 were killed on impact.
United Airlines Flight 811 was a regularly scheduled international flight from Los Angeles to Sydney, with intermediate stops at Honolulu and Auckland. On February 24, 1989, the Boeing 747-122 serving the flight experienced a cargo-door failure in flight shortly after leaving Honolulu. The resulting explosive decompression blew out several rows of seats, killing nine passengers. The aircraft returned to Honolulu and landed without further incident.
China Airlines Flight 006 was a daily non-stop flight from Taipei to Los Angeles International Airport. On February 19, 1985, the Boeing 747SP operating the flight was involved in an aircraft upset accident, following the failure of the No. 4 engine, while cruising at 41,000 ft (12,500 m). The plane rolled over and plunged 30,000 ft (9,100 m), experiencing high speeds and g-forces before the captain was able to recover from the dive, and then to divert to San Francisco International Airport. Twenty-four occupants were injured.
An Air Data Inertial Reference Unit (ADIRU) is a key component of the integrated Air Data Inertial Reference System (ADIRS), which supplies air data and inertial reference information to the pilots' electronic flight instrument system displays as well as other systems on the aircraft such as the engines, autopilot, aircraft flight control system and landing gear systems. An ADIRU acts as a single, fault tolerant source of navigational data for both pilots of an aircraft. It may be complemented by a secondary attitude air data reference unit (SAARU), as in the Boeing 777 design.
During the 1990s, a series of issues affecting the rudder of Boeing 737 passenger aircraft resulted in multiple incidents. In two separate accidents, pilots lost control of their aircraft due to a sudden and unexpected rudder movement, and the resulting crashes killed everyone on board, 157 people in total. Similar rudder issues led to a temporary loss of control on at least one other Boeing 737 flight before the cause of the problem was ultimately identified.
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 because of a rudder malfunction. The crew were able to regain control and land the aircraft successfully. All 53 occupants on board the 737-200 survived with no injuries.
Continental Airlines Flight 1404 was a Continental Airlines domestic flight from Denver International Airport in Denver, Colorado, to George Bush Intercontinental Airport in Houston, Texas. On the evening of December 20, 2008, the flight crashed while taking off from Denver, resulting in two critical injuries, 36 noncritical injuries, and a hull loss of the Boeing 737-524 aircraft.
USAir Flight 427 was a scheduled flight from Chicago's O'Hare International Airport to Palm Beach International Airport, Florida, with a stopover at Pittsburgh International Airport. On Thursday, September 8, 1994, the Boeing 737 flying this route crashed in Hopewell Township, Pennsylvania while approaching Runway 28R at Pittsburgh, which was USAir's largest hub at the time.
UPS Airlines Flight 6 was a scheduled international cargo flight operated by UPS. On September 3, 2010, the Boeing 747-400F flying the route between Dubai, United Arab Emirates, and Cologne, Germany, developed an in-flight fire, which caused the aircraft to crash, killing both crew members, the only people on board. It was the first fatal air crash for UPS Airlines. The accident prompted a re-evaluation of safety procedures protecting airliners from cockpit smoke.
Southwest Airlines Flight 812 was a Boeing 737-300 passenger jet that on April 1, 2011, suffered rapid depressurization while cruising at 34,000 ft (10,000 m) near Yuma, Arizona, leading to an emergency landing at Yuma International Airport. Two of the 122 people on board suffered minor injuries. The aircraft was operating Southwest Airlines' domestic scheduled service from Phoenix, Arizona, to Sacramento, California.
National Airlines Flight 102 (N8102/NCR102) was a cargo flight operated by National Airlines between Camp Shorabak near the city of Lashkargah in Afghanistan and Al Maktoum Airport in Dubai, with a refueling stop at Bagram Airfield, Afghanistan. On 29 April 2013, the Boeing 747-400 operating the flight crashed within the perimeter of the Bagram airfield moments after taking off, killing all seven people on board.
American Airlines Flight 383 was a scheduled domestic passenger flight from O'Hare International Airport in Chicago, Illinois to Miami International Airport. On October 28, 2016, the Boeing 767-300ER operating the flight suffered an engine fire during takeoff. The crew aborted their takeoff, evacuating everyone on board, of whom 21 were injured. The plane was a write-off.
Southwest Airlines Flight 1380 was a Boeing 737-700 that experienced a contained engine failure in the left CFM International CFM56 engine after departing from New York–LaGuardia Airport en route to Dallas Love Field on April 17, 2018. The engine cowl was broken in the failure, and cowl fragments damaged the fuselage, shattering a cabin window and causing explosive depressurization of the aircraft. Other fragments caused damage to the wing. The crew carried out an emergency descent and diverted to Philadelphia International Airport. One passenger was partially ejected from the aircraft and sustained fatal injuries, while eight other passengers sustained minor injuries. The aircraft was substantially damaged.
Pan Am Flight 799 was an international cargo flight from Los Angeles International Airport to Cam Ranh Airport in South Vietnam that crashed on December 26, 1968, near Anchorage, Alaska. The aircraft involved was a Boeing 707-321C aircraft operated by Pan American World Airways. All three crew members died in the crash.
Omega Aerial Refueling Services Flight 70 was scheduled to provide aerial refueling to US Navy F/A-18 fighter jets. On May 18, 2011, it crashed on takeoff following engine separation. All 3 crew members on-board survived.
N661US is an aircraft that was built by Boeing as the prototype of the Boeing 747-400, a modernized version of the Boeing 747. The plane rolled off the assembly line on January 26, 1988, and had its first flight on April 29, 1988. After the 747-400 flight testing program had concluded, Boeing delivered the aircraft to Northwest Airlines on December 8, 1989.
Rudder hardover: The sustained deflection of a rudder at its full (blowdown) travel position.