The world’s mystery for the last month has been the fate of Malaysia Airlines flight 370, which vanished on March 8 shortly after departing Kuala Lumpur on a routine, twice-daily flight to Beijing. The airplane was a modern Boeing 777-200, one of the most common airliners in service and which has only been involved in one fatal crash in the last 20 years. The captain had over 18,000 hours of flight time, and the airline had a safety record on par with any U.S. or European carrier. What went wrong? At this point, there are no answers and very few leads – not even a clear picture of where the aircraft is. But let’s go over what we know so far.
MH370 departed Kuala Lumpur around midnight and climbed to its cruising altitude of 35,000 feet, reporting nothing unusual along the way. About 40 minutes into the flight, as the aircraft was transferred from Malaysian to Vietnamese air traffic control, radio and secondary radar contact were lost.
Aircraft communicate with the ground in a variety of ways. When near land, pilots talk directly to air traffic controllers over VHF radios, and aircraft are tracked via secondary, or passive, radar. This type of radar sends out a radio “ping”, effectively calling “who’s out there” into the sky. All commercial aircraft are equipped with transponders, which hear the radar’s greeting and respond with a message like, “Hi, I’m MH370 at 35,000 feet, 450 knots, my coordinates are xx.xx east, yy.yy north, and everything is normal.”
So when controllers say they “lost contact” with MH370, they mean that the pilots stopped responding to radio messages and the airplane’s transponder stopped answering secondary radar pings. Communication failures do occur – transponders and radios stop working sometimes, and there are procedures in place for aircraft to land safely without air traffic control contact. This occurs rarely but regularly and is not an emergency. But in this case, the sequence in which communications were lost has led the investigation to conclude that the airplane’s transponders, radios, and an additional data-link system were turned off deliberately.
After this loss of communication, there are only a few leads for the investigation to follow. The airplane made a sharp left turn and actually flew back over the Malaysian peninsula, passing over several major cities. We know this because, about a week after the incident, an unidentified aircraft tracked by Malaysian military radar – this time primary radar which detects physical objects rather than transponders – was confirmed to be MH370. It is unclear why there was no immediate response to a “silent” aircraft breeching Malaysian airspace.
Next, we know that the airplane turned left again and climbed and descended several times, eventually settling on a southbound path into the vast Indian ocean, with nothing ahead but Antarctica.
There is only one more clue as to what happened. The satellite communication system, which was turned off in the initial loss of contact, still sent hourly pings to the nearest satellite, similar to how your cell phone periodically sends a “hello” to the nearest cell towers. Through an analysis of the precise angle that the signals traveled on their way from the aircraft to the satellite along with the exact time that it took them to get there, the investigation has determined that the last ping occurred somewhere along an approximately 1,500-mile arc in the southern Indian Ocean. The speed of the aircraft was also estimated from these pings, and by taking into account the winds aloft and the normal fuel burn, it was possible to make an educated guess as to where the airplane ran out of fuel and then crashed into the ocean.
But, this educated guess is not a very good starting point for a search in one of the most remote and hostile parts of the planet. The search area is currently about the size of Ireland, and the object of interest is about 200 feet long when intact – but is now likely broken into a widely scattered debris field, some of it floating but most of it on the sea floor nearly two miles down.
This is the challenge that the search team is facing, and this is why it has been possible to “lose” such a large and sophisticated vehicle and its occupants. An airplane is one of the safest places in the world to be, and events like this are extraordinarily rare. That said, the reality is that aircraft are small and their routes are extremely large. Out over the ocean we are alone in a way that we’re not accustomed to in the age of GPS and cell phones, even if the movies and Internet available on the airplane make it seem like nothing special is going on.
It’s possible that we will never really know what happened to MH370, although I tend to think this is unlikely. The aviation industry does not like uncertainty and at all levels the No. 1 priority really is safety – if something happened to this airplane that could have been prevented, we need to find out. The search will continue for the foreseeable future, but it will almost certainly take years for answers to emerge.
The disappearance of MH370 is disturbing, but the thing to focus on is the rarity of any sort of air disaster. There are millions of flights per year and always a single-digit number of accidents – and many years, that digit is zero. Flying is as safe as ever, and Malaysia Airlines has a safety record on par with any western carrier; this is the second fatal crash in its 50-year history.
To me, the ability to eat somewhat identifiable “chicken or beef” while watching a movie and safely blasting through the sky at 600 miles per hour is a stunning achievement. Aviation was a key driver of my interest in science, engineering and the atmosphere, and I still love feeling the power of the engines as we accelerate and then the slight lift and sudden smoothness as the airplane’s weight is transferred from the wheels to the wings. Perhaps the most amazing part is that we’ve turned flight into a regular, precise and safe method of transportation – and a very public demonstration of what science is capable of.