Safety

How the NTSB Makes Air Travel Safer

By Blair Watson, Special to Aviation.com

posted: 25 June 2008 05:13 pm ET

: A Southwest Airlines Boeing 737 rests nose first in the intersection of W.55th Street and Central Ave. in Chicago after it skidded off the runway at Midway Airport on the night of Thursday Dec. 8, 2005. Flight 1248 from Baltimore to Chicago tried to land in heavy snow but slid off the end of the runway, crashing through the boundary fence and crushing a car, killing a passenger. The accident, Southwest Airlines' first-ever involving a fatality, was promptly investigated by the National Transportation Safety Board. Credit: AP Photo/Charles Rex Arbogast

For more than four decades, the National Transportation Safety Board (NTSB) has investigated aircraft accidents and recommended changes that have saved the lives of countless air travelers.

Since its formation on April 1, 1967, the NTSB has become one of the world’s premier accident investigation agencies, employing hundreds of specialists who have investigated some 130,000 aviation accidents. The NTSB also investigates rail, highway, marine and pipeline accidents.

Until 1975 the NTSB was part of the Department of Transportation (DOT). However, its organizational ties to the DOT were severed in 1975 to ensure independence from the Federal Aviation Administration and other DOT agencies.

The NTSB has five members appointed by the President for 5-year terms, one of whom is designated the chairman and approved by the Senate for a 2-year term. Another member is designated as vice-chairman and becomes acting chairman when there is no formal chairman. No more than three of the five NTSB members can be from the same political party.

NTSB aviation accident investigators work out of offices in 10 U.S. states (including Alaska), as well as a “Telework” office in Hawaii. They travel throughout the U.S. and to other countries to investigate significant accidents and develop factual records and safety recommendations.

The NTSB has investigated accidents involving a very wide variety of aircraft, from World War II-vintage, single-seat airplanes to modern jetliners that carry hundreds of passengers.

NTSB 'Go Teams'

As soon as the NTSB is notified of an aircraft disaster, it dispatches a 'Go Team' to "begin the investigation of a major accident at the accident scene, as quickly as possible, assembling the broad spectrum of technical expertise that is needed to solve complex transportation safety problems,” in the agency's words.

The team comprises three or four to more than 12 specialists — depending on the scale of the accident — from NTSB headquarters in Washington, D.C. Go Teams are assigned on a rotational basis to respond to catastrophic airline crashes as quickly as possible, traveling to the accident scene on commercial or government aircraft.

Because Go Team members never know when they will be contacted about a major accident, they have their tools — digital cameras and a voice recorder, wrenches, screwdrivers, flashlights and other devices — packed and ready to go. Investigators can be sent to any part of the world, from major cities to remote Arctic, desert or jungle regions.

The Go Team leader is the Investigator-in-Charge (IIC), a senior investigator with years of NTSB and industry experience. Each investigator is a specialist responsible for a major aspect of the investigation. Areas of specialty are operations, structures, powerplants (engines, and propellers when applicable), aircraft systems, air traffic control, weather, human performance and survival factors.

Black boxes provide vital clues

Every airliner and business aircraft has a flight data recorder (FDR), which provides critical information about what was happening to the aircraft up to its final moment. The latest FDRs record hundreds of different parameters of information. Each aircraft also has a cockpit voice recorder (CVR), which captures the last 30 to 120 minutes — depending on the make and model of the CVR — of words spoken by the pilots and received in the cockpit from air traffic control.

The CVR's microphones also can be sensitive enough to capture other cockpit and external sounds that sometimes can provide clues to the proximal cause of an accident — for instance, the sound of an explosion — and can help pinpoint the direction from which such sounds came.

Both "black boxes" — which usually are colored bright orange, to be easily noticeable at crash scenes, where they might have ended up some distance away from the rest of the aircraft — are of rugged design and construction. This is so that they can survive the high forces of a high-speed impact with the ground well enough to prevent the vitally important data they have recorded from being completely lost. Today's FDRs and CVRs are built with solid-state memory storage to improve the chances of their data remaining intact for transcription and analysis following an accident.

The FDR and CVR recovered from an accident site are carefully transported to the NTSB's laboratories in Washington, D.C. There technicians retrieve the data and audio recordings for accident investigators. Using FDR data, computer animation is created to help investigators understand the airplane’s movements better and its performance in the period leading up to the accident.

NTSB recommendations and aviation safety

Since 1967, the NTSB has issued more than 6,000 recommendations to improve air safety. Nearly every aspect of aviation has been affected, including aircraft design and maintenance, the training of pilots, air traffic controllers and other personnel, and airline and airport operations.

A recent NTSB recommendation— issued less than two weeks ago — affects the best-selling EA-500 very light jet (VLJ) from Eclipse Aviation of Albuquerque, NM. “The National Transportation Safety Board today issued two urgent recommendations to the Federal Aviation Administration to address a safety issue concerning a failure that resulted in uncontrollable engine thrust in an Eclipse 500 airplane and the lack of emergency procedures developed for that failure,” the agency said in a June 12 statement.

More than 200 EA-500s have been delivered to companies and private individuals and Eclipse Aviation has more than 2,000 orders for its VLJ. The Federal Aviation Administration issued an Emergency Airworthiness Directive for the EA-500 on June 13, just a day after the NTSB made its recommendations. The emergency directive required an immediate inspection of each EA-500's trust levers to make sure they weren't making "unusual noises" such as grinding or scraping, which might have indicated they could become stuck.

NTSB recommendations have been instrumental in making flying a very safe form of travel in comparison with other means of transportation. For example, U.S. air carriers transported an estimated 770 million passengers last year and according to the NTSB, a total of 44 people died in 62 air carrier accidents. In contrast, more than 44,000 people died in vehicle accidents in the United States in 2007.