As I look back on the year 2014, it’s hard not to be struck by the sheer number of flights that disappeared or were lost. It seems as if every week brought news of another missing plane, each more mysterious than the last. It’s tempting to think of these incidents as isolated occurrences, unrelated to each other or to any broader trends. But a closer look reveals a very different story.

Let’s start with Malaysia Airlines Flight 370, which disappeared on March 8, 2014. This was arguably the most high-profile disappearance of the year, and it captured the world’s attention for months. The search for the missing plane was one of the largest and most expensive in history, and yet no trace of the aircraft was ever found. Theories abound as to what might have happened, from mechanical failure to pilot suicide to hijacking by terrorists. But whatever the explanation, the fact remains that a modern airliner with 239 people on board simply vanished without a trace.

Then there was AirAsia Flight 8501, which disappeared on December 28, 2014. Like MH370, this plane was en route to China when it went missing, and again, no trace of the aircraft was found for several days. When debris from the plane was finally located, it was clear that the plane had crashed into the sea, killing all 162 people on board. The cause of the crash was determined to be a combination of pilot error and a malfunctioning rudder control system, but again, the fact that a plane could disappear so completely in the age of GPS and satellite tracking is deeply troubling.

And those were just the high-profile disappearances. In total, there were at least eight commercial airliners that went missing in 2014, with a total of more than 600 people on board. Some of these incidents were eventually resolved, with wreckage and bodies being found, but others remain shrouded in mystery.

So what does all this mean? Well, for one thing, it’s clear that the aviation industry has a serious problem when it comes to tracking and locating planes that go missing. In the wake of the MH370 disappearance, there was a lot of talk about improving satellite tracking and other technologies, but it’s not clear that much has actually been done in this regard. And while some of the disappearances can be chalked up to pilot error or mechanical failure, others are more sinister in nature, raising uncomfortable questions about security and terrorism