The safety records of air carriers flying the same nonstop routes are so similar that flyers cannot expect to improve their odds by choosing some carriers over others, says an MIT expert in air safety.
"While there are some big differences in airline safety records, these differences wither away when two airlines compete on the same route," says Arnold I. Barnett, George Eastman Professor of Management Science at MIT's Sloan School of Management. "Thus, it is not clear that travelers can benefit by favoring some airlines and shunning others.
"In particular, recent death-risk statistics do not support the oft-repeated assertions that established airlines in the U.S. are safer than newly-formed ones, that U.S. carriers are the safest in the world, or that First World carriers are systematically safer than Third-World airlines. Many of the differences in observed safety records could be ascribed either to differences in flying environments or to short-term fluctuations in luck."
The remarks are based on a paper, "Aviation Safety in Numbers," that is being presented at a convention of the Institute for Operations Research and the Management Sciences (INFORMS®). Prof. Barnett delivers the Omega Rho Distinguished Lecture Plenary Address in the Philadelphia Marriott Hotel on Sunday, November 7 at 4:45 PM.
Professor Barnett has been described on NBC News as the nation's leading expert on aviation safety. He has worked for three airports and ten airlines, and headed an FAA research team formed at the request of the White House Commission on Aviation Safety and Security to investigate antiterrorist measures. Challenging Popular Perceptions
In his speech, Professor Barnett makes the following major points:
- The death risk per flight on established US domestic jet carriers was 1 in 7 million over 1987-96. At that rate, a person who flew one flight every day would on average go 19,000 years until suffering a fatal accident. This statistic means not only that the risk is infinitesimal on individual flights, but that even frequent flyers face minimal cumulative risk.
- Over 1987-96, post-deregulation new entrant jet carriers performed 3 million flights and suffered one fatal crash. There is no statistically significant difference between this outcome and the fatal-accident record of established US jet carriers. However, that one crash was the 1996 ValuJet disaster, which led to widespread concerns about the safety of new-entrant airlines and contributed to the demise of several of them. (Professor Barnett discloses that he was hired by a law firm to defend Valujet after the crash).
- The death risk per flight over 1987-96 was about 1 in 2 million on US commuter air carriers (short haul flights on propeller or propjet aircraft). Given the number of fatal events over the period, this statistic is significantly higher than the corresponding one for US domestic jet operations. However, jet and commuter planes generally fly different routes, and the risk disparity may reflect variations in flying conditions rather than differences in safety.
- Data from 1987-96 do not support assertions that US carriers are "the safest in the world." For both domestic and international jet operations, death risk per flight was higher for US carriers than their counterparts elsewhere in the First-World. However, the difference was not statistically significant, and was well within the range of year-to-year fluctuations in fatal-accident rates. First-World jet carriers are homogeneous in aviation safety, much as First World nations are homogeneous in road safety, rail safety, industrial safety, and life expectancy.
- Passenger death risk per flight over 1987-96 was about 15 times as high on domestic jet flights in the Developing World as in the First World. The discrepancy is about a factor of 7 on international jet routes.
- However, First World carriers did not outperform Developing World airlines at all over 1987-96 on routes for which the two groups of carriers directly compete, namely, those routes linking the two "worlds" (e.g. Paris-Karachi, Miami-Sao Paulo, Tokyo-New Delhi). Operations in the Developing World appear to entail higher risks for all airlines that perform them, and not just for local carriers.
- Based on his research assessing safety performance over given periods, Prof. Barnett believes that the most accurate conclusions are based on "bottom line" statistics about passenger death risk. He sees little merit in popular attempts to connect a carrier's record of nonfatal mishaps with the risk of a fatal crash.
Philadelphia Convention
Members of the Institute for Operations Research and the Management Sciences (INFORMS®) will hold a national convention place at the Philadelphia Marriott Hotel from Sunday, November 7 to Wednesday, November 10. The theme is "ORMS and the Quality of Life." The convention will include sessions on topics applied to numerous fields, including commuter transit, e-commerce, health care, information technology, energy, transportation, marketing, telecommunications, and sports. More than 1,600 papers are scheduled to be delivered. Additional information about the conference, including a full list of workshops, is at http://www.informs.org/Conf/Philadelphia99/ and http://www.informs.org/Press .
The Institute for Operations Research and the Management Sciences (INFORMS®) is an international scientific society with 12,000 members, including Nobel Prize laureates, dedicated to applying scientific methods to help improve decision-making, management, and operations. Members of INFORMS work in business, government, and academia. They are represented in fields as diverse as airlines, health care, law enforcement, the military, the stock market, and telecommunications. The INFORMS website is at http://www.informs.org .