Nate Silver has a proven track record for using statistics wisely, which is why I was intrigued by a chart he posted on his blog fivethirtyeight.com today.
The chart tracks "violent passenger incidents" on airplanes since the 1930s, when commercial aviation became a big deal in the U.S.
He got his data from PlaneCrashInfo.com, the most complete (but not perfect) database of aviation calamities on the Internet. From the database, Silver compiled the number of passenger fatalities from sabotage (such as bombings to collect life insurance or to make a political statement), hijackings, and pilot shootings. He also counted deaths on the ground caused by the crashing of the planes.
Because many more people fly now than did years ago, he has done the math to see how many violent deaths there are per billion of passengers who fly.
The chart shows that about 22 passengers per one billion enplanements were killed as the result of violent plane incidents during the 2000s, but deaths on the ground because of 9/11 added more than 3,000 deaths to the total. So there were 151 deaths in the U.S. for every one billion passenger boardings.
The surprise to me is that deaths due to violent passengers, both in the sky and on the ground, has been a feature of flight for a long time.
That is not to minimize the tragedy of 9/11 by any means. As Silver says, "Since the beginning of commercial air travel, a total of about 6,500 people have been killed as the result of Violent Passenger Incidents—nearly half of those, or 2,995, came on 9/11 itself." It was a horrible day, and there are terrorists out there who want to repeat the uniquely awful tragedy.
That said, the chances of dying from airplane related violence has been pretty steady since the 1930s.