Tracking Transport: How Can MH370 Go Missing?
Flight MH370 has been missing for nearly two months. To the world, this Boeing 777-200ER and its 239 passengers and crew have disappeared off of the face of the Earth. Yet, in the 21st Century, with access to life-changing and groundbreaking technology, how can we lose a modern aircraft?
The eight primary countries assisting in the search - Australia, New Zealand, Malaysia, Japan, South Korea, the United States, Britain and China – have now called off the aerial search with no discovery of any debris.
One thing that has become clear from the investigation so far is that key communications equipment on the flight were turned off. Ordinarily, aircraft, whether commercial or freight, are tracked by an extensive global radar system. This system will be either ‘Primary Radar’, where microwave radiation is transmitted and then returns as an echo, providing an approximate location of the aircraft whether it wants to be tracked or not, or ‘Secondary Radar’ which requires the aircraft to have an internal piece of equipment, the transponder, functioning correctly. The transponder will receive coded microwave energy and then transmit its own coded microwave energy back. This was not the case on flight MH370 – the transponder had been switched off. Radar does not, however, function if the aircraft is more than 250km out to sea as this surpasses its range. From this point, pilots will stay in contact with air traffic control by making periodical radio broadcasts. But radar must be given credit in this investigation – it was military radar after all that showed MH370 to have changed course, from flying North-East to due West.
The first question that tends to be asked about tracking flights is ‘why can’t you use GPS?’ While pilots will use GPS to plot their location on a map, this data is not usually shared with air traffic. There is the option for the plane to uplink the GPS data to satellite tracking services, but this data is large so handling becomes very expensive. Radar information is also stored for 30 days, but again, due to the extreme size of the data, it is stored for no more time due to expense. Then of course there are the online websites which allow live tracking of aircraft – but, once again, they can only store so much data and will only provide information gathered from standard radar and air traffic. They will know only as much as we do.
So what about satellites? Around 3000 satellites currently circle the earth, so surely one of them saw something? The majority of satellites are only communications or has another function that means they are not photographing the Earth. Of those that were photographing the Earth at this time, such as spy-satellites, their coverage has been investigated and no further information has been found.
The two final systems this leaves are the Aircraft Addressing and Reporting System (ACARS) and the ‘Black Box’. ACARS essentially allows the in-flight computers to communicate with computers back on the ground about how the aircraft systems are functioning. Yet, the final message from the ACARS on MH370 came at 01:07, and investigation has led to believe that it was purposefully shut down. As for ‘Black Boxes’, when found they can provide every detail needed to know what went wrong. The only problem is they have no tracking system other than emitting ultrasonic signals, but these have a very limited range. The black box might only be found if a search team is right above the crash site.
The tracking of aircraft is extensive and, providing the aircraft has all systems switched on and functioning correctly, there should be no reason for it to go missing. While flight MH370 appears to be lost forever, this doesn’t mean it will never be recovered - only two months have passed so far. In the case of Air France flight 477, which crashed over the Atlantic, it took nearly two years.