Independent U.S. agency responsible for the investigation of civil aviation, railroad, highway, marine, and pipeline accidents within the United States and for the issuing of safety recommendations designed to prevent future accidents.
The National Transportation Safety Board (NTSB) was established by Congress in 1967 to investigate the causes of all transportation-related accidents involving aviation, railroads, highways, marine craft, or pipelines. Although the NTSB’s funding appropriations came from the Department of Transportation (DOT), the NTSB functioned independently of the DOT. In 1975, Congress passed the Independent Safety Board Act, which formally severed all ties between the NTSB and DOT.
NTSB investigators operate twenty-four hours a day, seven days a week, investigating accidents within the United States as well as accidents involving U.S. crafts overseas. Once NTSB teams reach the crash site, they evaluate the evidence to determine the probable cause of the accident and issue safety recommendations to prevent a recurrence.
Since opening its doors in 1967, the NTSB has investigated more than 110,000 aviation accidents. Although the NTSB does not have the regulatory power to enforce its recommendations, approximately 82 percent of its 11,000 safety recommendations have been implemented by the Federal Aviation Adminstration (FAA).
The NTSB is responsible for investigating all civil aviation accidents in the United States. The number of civilian takeoffs and landings exceeded 63 million in 1997, and the number of passengers flying rose from 580 million in 1995 to 630 million in 1997. The safety of these commercial flights rests with the NTSB, which focuses on specific problems, such as operations, cabin safety, weather, and aircraft design, when issuing its recommendations for improved safety.
One of the principal recommendations in the area of operations involves the addition of ground proximity warning systems (GPWS) for aircraft equipped with ten or more seats. The recommendation was issued after an Eastern Air Lines Lockheed L-1011 crashed into the Florida Everglades on December 29, 1972 and a TWA Boeing 727 crashed into a mountain on its approach to Washington Dulles International Airport in Virginia on December 1, 1974. One hundred ninety-one people died in these two crashes, and, after thorough investigations of each, the NTSB determined that the cause of both accidents was “controlled flight into terrain,” which could have been prevented if the aircraft had been equipped with warning systems. In 1975, the FAA implemented the NTSB recommendation that all large passenger aircraft be equipped with ground proximity warning systems that alert the crew if terrain is approaching, if the plane is descending too quickly, and if the landing gear is not functioning properly. In 1994, the original recommendation was expanded to include smaller aircraft capable of carrying as few as ten passengers.
A second area of concern for the NTSB involves fire safety. On several occasions, fires that started in aircraft lavatories or cargo areas have resulted in fatalities. In July, 1973, the NTSB recommended that airplanes be equipped with smoke detectors after a Boeing 707 crashed near Paris, France, after a fire started on board. After several more incidents, the NTSB recommended, and the FAA mandated, that automatic-discharge fire extinguishers be installed in all aircraft trash receptacles. Airline attendants are also required to routinely check the containers. After a fatal fire occurred on board an Air Canada flight that was forced to land at Cincinnati, the NTSB recommended that all lavatories be equipped with smoke alarms, that floor-level lighting be installed for passenger safety during an emergency evacuation, and that fire-blocking materials be used in all cabin and seat material. In addition, the NTSB recommended that all emergency slides be equipped with a heat-resistant coating to prevent injury to passengers during a postcrash evacuation. In 1981, after a fatal fire on board a Lockheed L-1011 out of Riyadh, Saudi Arabia, the NTSB issued a recommendation for aircraft modifications aimed at preventing the spread of fires from cargo areas to the cabin. Additional restrictions on the containment of cargo fires followed the crash of a South African Airways Boeing 747 that crashed into the Indian Ocean with the loss of all 160 people on board.
The most serious weather-related problem addressed by the NTSB involves wind shear. The first instance of NTSB involvement with the weather phenomena occurred in 1968, and since that time, the NTSB has issued more than sixty safety recommendations. The most serious crash involving wind shear occurred at Dallas-Fort Worth International Airport on August 2, 1986, when a Delta Air Lines Lockheed L-1011 crashed, killing 135 people on board. Investigators examined the data and suggested the need for additional pilot training specifically geared toward this type of weather condition and for the installation of low-level wind shear alert systems at all major airports. As a result, the terminal Doppler weather radar (TDWR) warns pilots and air traffic controllers allowing them to prevent possible disasters. Since 1985, only one wind shear-related accident has occurred, at Charlotte, North Carolina, where the TDWR system was not yet operational.
Another potential weather-related issue that the NTSB has investigated deals with icing. The accumulation of ice on airplanes has been a problem since the early days of aviation, but it was not until the crash of a USAir Fokker F-28 at New York’s LaGuardia International Airport in 1976 that the NTSB issued specific recommendations concerning the measurement and forecasting of icing on airplanes and protection against it. The FAA implemented these recommendations. In 1994, the NTSB issued additional warnings about icing problems on the ATR-72 passenger planes, and the FAA ordered the modification of deicing systems the following year.
As the number of aircraft operating in limited airspace multiplied, midair collisions began to increase. As early as 1967, the NTSB advocated the development of a system designed to prevent such accidents. The proposed technology would be separate from the air traffic control system and would offer the earliest possible warning of a potential crash. In 1993, the FAA ordered that all aircraft used for transport be equipped with traffic alert and collision avoidance systems (TCAS). Mode C transponders, located near major airports, analyze the altitude of airplanes equipped with the device and alert air traffic controllers, who then warn the airplanes before a disaster occurs. Since the implementation of this recommendation, the number of near-midair collisions has dramatically decreased.
When evaluating the causes of crashes, the NTSB examines aircraft design and has revealed several areas where modifications were necessary. While investigating a crash that occurred when an American Airlines DC-10 attempted to take off from Dallas-Fort Worth International Airport on May 21, 1988, the NTSB discovered that the minimum specifications for the brake friction material were inadequate for a rejected takeoff that required more than twice the minimum amount of material to stop safely. As a result, the FAA increased the safety standard and ordered additional training for pilots to improve passenger safety during aborted takeoffs.
Another area of concern involves the length of airport runways. The FAA requires a 1,000-foot safety area at the end of runways for emergencies. Newer airports have allowed for plenty of room, but older airports frequently have sharp drops in terrain at the ends of runways. A 1994 crash at LaGuardia International Airport prompted investigators to recommend the use of soft-ground arresting systems to slow airplanes down in the event of an emergency. Arrestor-beds have prevented accidents at many airports, including John F. Kennedy International Airport in New York.
Always cognizant of the possibility of human error, the NTSB has advocated several changes that would improve the safety of passengers. One recommendation included cross-referencing pilots’ licenses with the National Driver Register (NDR) to check for alcohol-related violations that could indicate a potential problem that would adversely affect a pilot’s performance during flights. Since the late 1980’s, the NTSB has also recommended random drug screening. Another area of particular concern involves the interaction of crew members. The NTSB found that on numerous occasions, because the pilot remains the final authority in the cockpit, other crew members were hesitant to warn the pilot of potential problems for fear of reprimand. On December 28, 1978, a United Air Lines DC-8 ran out of fuel and crashed on approach to Portland, Oregon, killing ten people, because the first officer had failed to communicate the problem to the pilot. The NTSB found that improved crew management would reduce potential fatalities, and the FAA ordered a crew management training program for all major airlines.
Aircraft design flaws account for many fatalities, and the NTSB has issued numerous recommendations based on their investigations of accidents caused by such flaws. In 1991, the NTSB examined the wreckage of an Atlantic Southeast Airlines EMB-120 that crashed in Georgia and found that excessive wear on the propeller-control unit had rendered the aircraft uncontrollable. After the NTSB issued its report, the FAA required the installation of a fail-safe device that prevents propellers from rotating too far. In its investigation of another crash in Georgia in 1995, the NTSB found that a small crack had developed in the aircraft’s propeller, resulting from the improper installation of a propeller blade. As a result of this investigation, the NTSB advocated the use of ultrasonic inspection techniques to detect future problems. After the crash of a Turkish Airlines DC-10 near Paris, France, in 1974, the NTSB suggested the use of blowout pressure-relief doors to prevent a recurrence of an explosion that would buckle the cabin floor and damage flight controls. In 1989, the NTSB investigated a similar incident. On February 24 of that year, a United Air Lines Boeing 747 took off from Honolulu, Hawaii, bound for New Zealand. During the airplane’s ascent, the lower cargo door flew off, but the modifications implemented as the result of the Turkish Airlines crash saved the 355 lives on board.
In addition to accidents caused by faulty airline design, the NTSB also investigates accidents involving structural fatigue and corrosion. On April 28, 1988, the NTSB investigated the structural failure of an Aloha Airlines Boeing 737-200 that lost a portion of its fuselage during takeoff from Hilo, Hawaii. The force of decompression during the accident resulted in one flight attendant being sucked out of the plane. After examining the aircraft, the NTSB recommended numerous changes in the structure and design of similar aircraft.
The NTSB offers additional recommendations in numerous areas, including the improved quality of off-wing escape slides, fuel-tank protection, and safety belts. In addition to airplane safety, the board is also interested in the safety of helicopters and investigates problems involving the in-flight loss of the main rotor control and the need for flight restrictions during adverse weather conditions. More recently, the NTSB has worked with the National Aeronautics and Space Administration (NASA) to determine the survivability of space orbiters. The NTSB was involved in the investigation of the 1986 space shuttle Challenger explosion. NTSB investigators also located a flaw in a crashed Titan 34D military launch vehicle, enabling the problem to be addressed before another accident occurred.
Over the past four decades, the National Transportation Safety Board has gained a reputation for its fair and impartial analysis of crash sites. The recommendations made by the board have been implemented with a high degree of success. Many lives have been saved, and the board continues to improve the safety conditions on commercial aircraft, earning the confidence of the traveling public. With only four hundred employees, the agency provides an invaluable service.
Collar, Charles S. Barnstorming to Air Safety. Miami, Fla.: Lysmata, 1997. Addresses the issues of safety and the recommendations and changes necessary to ensure the safety of persons who fly. Watson, Thomas W. Uphappy Landings: Why Airplanes Crash. Melbourne, Fla.: Harbor City Press, 1992. Deals with the causes of airplane accidents resulting from design and structural problems and weather-related issues. Wolfe, Louis. Disaster Detectives. New York: Julian Missner, 1981. An excellent look at NTSB investigators and the techniques they employ while analyzing transportation disasters.
Airline industry, U.S.
Federal Aviation Administration
National Aeronautics and Space Administration