1. Even after the headline-grabbing airline crashes in 2014 and Tuesday's Germanwings tragedy, flying remains one of the safest ways to travel.
"Statistically speaking, flying just keeps getting safer. Last year was still the safest air travel year on record," airline safety professor Anthony Brickhouse of Embry-Riddle Aeronautical University in Daytona Beach, Florida, told BuzzFeed News.
A 2006 analysis by Harvard's David Ropeik put the yearly odds of dying in a plane crash at 1 in 11 million. In contrast, the risk of dying in a car crash was 1 in 5,000.
2. Rather than a catastrophe causing a crash, most of the time accidents happen because a lot of little things go wrong.
Crash experts call it the "Swiss Cheese" accident model, Brickhouse said.
"You have to have all the holes in the slices line up to get a hole big enough for an accident to happen," he said.
That's because modern planes are designed with multiple, redundant systems to do the same jobs or compensate if something goes wrong. Big planes that normally have four working engines, for example, can easily fly with two.
"I once flew from Dulles to Narita, Japan, on a plane with only two engines," said Brickhouse, a former National Transportation Safety Board investigator. "I was probably watching a crash video from an investigation during the flight, and I didn't break a sweat."
3. Flight crews are also getting more training than ever.
Over the last decade, flight rules have tightened almost yearly for commercial airline pilots and crews.
In 2011, the Federal Aviation Administration (FAA) increased the flight time needed to qualify for commercial airline co-pilot jobs from 250 to 1,500 hours. In 2013, it also tightened rules to give flight crews more sleep, and last year required grounding and retraining for pilots who are graded deficient on any aspect of flying.
Although the Germanwings flight that crashed on Tuesday belonged to an economy flight subsidiary of Lufthansa, pilots and crews still have to undergo the same training and requirements to qualify to fly.
4. Most people actually survive airline accidents.
On July 6, 2013, Asiana Airlines Flight 214 crashed into a seawall at San Francisco International Airport on landing, killing three passengers. But 248 other passengers survived the incident.
"That's what is more typical," Brickhouse said. "The reality is that most crashes, there is a good opportunity to survive."
Between 1959 and 2011, only about one-third of "major" commercial plane accidents saw any fatalities, according to FAA records.
5. Germanwings Flight 9525 seems to be an anomaly.
Takeoffs and landing are the most dangerous times for flight, not during cruising.
Only about 11% of fatal accidents happen during the cruise portion of the flight when Germanwings Flight 9525 crashed on Tuesday. More dangerous is landing, according to that FAA analysis, when about 37% of fatal accidents happen.
Flight 9525's sudden descent to 11,000 feet high from a cruising altitude of 38,000 feet above the Alps, as reported in some news accounts, is a red flag for investigators, Brickhouse said.
"Obviously, there is no reason for that kind of descent in a normal flight," he said.
6. The reason for a crash isn't always the one everyone assumes right from the start.
In June of last year, a private plane crash over Central Florida that killed six passengers triggered fears of weather software steering pilots into thunderclouds. It took six months to find out that faulty autopilot and an overreaction by the pilot likely ripped the wings off the plane.
"An accident investigation is like solving a puzzle with some of the pieces not matching, or some of the pieces missing. It isn't always easy or simple," Brickhouse said. "The one thing people really need is patience when trying to understand what caused one of these tragedies."