Traveling on commercial airlines has never been safer, according to a new study by an MIT professor tracking the continuing decline in passenger deaths around the world.
The study found that between 2008 and 2017, airline passenger deaths declined significantly compared to the previous decade, as measured per passenger on board — essentially the total number of passengers. Globally, this rate is now one death for every 7.9 million passengers on board, compared to one death for every 2.7 million passengers during the period 1998-2007, and one death for every 1.3 million passengers during the period 1988-1997.
Going back further, the risk of death for commercial airlines was one death for every 750,000 flights during the period 1978-1987, and one death for every 350,000 flights during the period 1968-1977.
“The risk of being killed globally has been falling by a factor of two every decade,” says Arnold Barnett, a researcher at the Massachusetts Institute of Technology who published a new paper summarizing the study’s findings. “Not only has that continued in the last decade, but the (recent) improvement is closer to a factor of three. And the pace of improvement has not slowed down at all even as flying is safer than ever and making more gains is more difficult. That’s really impressive.” It is important for people to take this into consideration.
The paper is titled “Aviation Safety: A Whole New World?” It was published online this month in the journal Transportation Science. Barnett is the sole author.
The new research also reveals that there is notable regional variation in airline safety around the world. The study found that the countries hosting the least risky airlines are the United States, members of the European Union, China, Japan, Canada, Australia, New Zealand and Israel. The overall risk of death among these countries was 1 death per 33.1 million passengers during the period 2008-2017. Barnett chose the nation as the unit of measurement in the study because important safety regulations for both airlines and airports are determined at the national level.
For airlines in the second group of countries, which Barnett calls the “advanced” group with a moderate risk level, the rate is one death for every 7.4 million flights over the period 2008-2017. This group—which includes countries that are generally rapidly industrializing and have recently achieved increases in overall life expectancy and per capita GDP—includes many countries in Asia as well as some countries in South America and the Middle East.
For a third and more vulnerable group of developing countries, including some countries in Asia, Africa and Latin America, the risk of death over the period 2008-2017 was one for every 1.2 million passengers on board – an improvement from one death for every 400,000 passengers on board. On board the aircraft during the years 1998-2007.
“The two most obvious changes compared to previous decades were the sharp improvements in China and Eastern Europe,” says Barnett, who is the George Eastman Professor of Management at the MIT Sloan School of Management. He points out that these places had achieved safety achievements in the past decade that were strong even within the group of countries least at risk.
Overall, Barnett points out, the death rate has declined much faster than public concerns about flying.
“Flying has become safer and more secure,” Barnett says. “It’s 10 times safer than it was 40 years ago, although I bet anxiety levels haven’t gone down that much. I think it’s good to get the facts.”
Barnett is a long-standing expert in aviation safety and risk, and his work has helped put accident and safety statistics into context. Whatever the absolute numbers of aviation accidents and deaths – and they fluctuate from year to year – Barnett sought to measure these numbers against the growth of air travel.
To conduct the current study, Barnett used data from a number of sources, including the Aviation Safety Foundation’s Aviation Safety Network accident database. It mostly used data from the World Bank, based on information from the International Civil Aviation Organization, to measure the number of passengers carried, which now stands at nearly 4 billion passengers annually.
In this paper Barnett discusses the pros and cons of some alternative metrics that can be used to evaluate commercial air safety, including deaths per flight and deaths per passenger mile. He prefers to use the number of deaths per flight because, as he wrote in the paper, it “literally reflects the proportion of passengers who died during flights.”
The new study also includes historical data showing that even in today’s riskiest areas for commercial aviation, the fatality rate is better, overall, than it was in the leading air travel countries just a few decades ago.
“The risk now in the most vulnerable countries is basically the risk we used to face 40 to 50 years ago” in safer air travel countries, Barnett points out.
Barnett readily acknowledges that the research evaluates aggregate numbers, and does not provide a causal explanation for the air safety trend; He says he would welcome more research to try to explain the continued gains in air safety.
In the article, Barnett also points out that air fatality numbers from year to year vary significantly. In 2017, for example, only 12 people died during air travel, compared to 473 people in 2018.
“Even if the trend line is flat, the numbers will bounce up and down,” Barnett says. For this reason, he believes that looking at trends decade-by-decade is a better way to understand the full trajectory of commercial airline safety.
On a personal level, Barnett says he understands the types of concerns people have about flying. He began studying the subject in part because of his own fears about flying, and joked that he was trying to “make light of my fears in a way that might be publishable.”
These kinds of visceral fears may be normal, but Barnett says he hopes his work can at least build public knowledge about the facts and put them into perspective for people who are afraid of plane crashes.
“The risk is so low that the fear of flying is a bit like the fear of going to the supermarket because the roof might collapse,” Barnett says.
