In the 21st Century with all its modern technologies, one would think it is impossible to disappear or get lost. But Malaysia Airlines flight MH370 has shown that it is not so. One can disappear completely and not be traceable for a long time. How did this happen?
The sky is big, so big you can’t see it completely. Even with modern technology, the coverage of the sky is not complete at all times. There are satellites that pass over various regions, and the entire sky is seen by some instrument sometime, but that is either not all the time or not with good resolution. For example, INSAT satellites can see the Earth at all times, but they can only see large objects, while IRS satellites that have the resolution to see an aircraft are not geo-stationary and hence see a particular region only once in a few days. And an aircraft is not really visible on radar once it is far away.
Aircrafts have to make themselves visible to be seen by an air traffic controller. They use transponders that relay information about the plane to the air traffic controller. Apart from this, the pilot has a whole set of navigational tools which allow him/her to take the plane along a definite path, and airports along the way take note of passing planes. However, the communication system is entirely in the hands of the pilot and the plane’s electrical system. Pilots can easily make an aircraft invisible (intentionally or otherwise) if they wish to, by switching off the transponders and not responding to radio messages from the control towers.
The radars of control towers can directly track aircraft only when they are within viewing reach. Planes outside this reach can remain invisible. Air traffic controllers have long range but low resolution radars that can see far away. Even then, the farther away the aircraft, the higher it has to fly to be visible to the air traffic controllers.
High resolution military radars can track only nearby regions very effectively, making it impossible for enemy aircraft to remain invisible close to the country’s borders. But they also have a limited range. That is why, for example, armed forces use special planes called Airborne Early Warning And Control Aircrafts (AEWACs) for long range survey in war and intelligence gathering.
So, the question is not whether an aircraft sufficiently far from an airport can disappear, but why and how. The how is easy to answer – a pilot or the plane’s electronics can switch off power to the transponder and it would stop telling the world where it is. If intentionally or otherwise, the radio communication is unresponsive, i.e. if radio silence is maintained, then the disappearance is complete.
The question is, what caused the transponder in MH370 to go off?
It is more or less clear that the plane did not spontaneously disintegrate at its cruising altitude where it was last seen, or we would have seen some floating debris by now. It is also clear the plane was not where it was supposed to be, and flew with the transponders switched off for quite some time. So, why did the plane fly incognito?
One obvious suspicion is that the pilot was made to – by terrorists. This is a difficult speculation to sustain. In modern aircrafts, it is impossible to get into the cockpit without the pilot’s permission, and overruling the pilot (a safety feature in case the pilot suddenly falls ill) is lengthy and takes several minutes, during which the pilot has enough time to warn air traffic controllers that something is amiss. Even if a pilot lets someone in who plays mischief, he/she has enough time to inform air traffic control. But given how paranoid airlines are, it is extremely unlikely that a pilot would allow this. Even a crew member who is in on a hijack will give the pilot enough time to at least inform air traffic controllers of the situation, or relay the highjackers' demands.
Modern aircrafts like the Boeing 777 have a whole host of overlapping technologies to note everything and warn everyone in multiple ways of any problem. In the worst case scenario of a catastrophic failure, the aircraft black boxes emit signals that can be picked up for over a month. These black boxes are designed to withstand the most extreme conditions of an air accident and yet emit homing signals by which they can be detected. Also, a catastrophic explosion at a cruising altitude of around 11 km above the sea would create debris that would spread far and wide, and be visible over several miles, depending on how high the aircraft was when it disappeared. Also, aircrafts are not designed to be strong enough to survive impact with water and would disintegrate immediately. In this case too, the debris will be spread over a reasonably large area.
The problem with MH370 is that it seems to have disappeared completely. It was flying at its cruising altitude over the South China Sea towards Beijing as expected, and was about to enter Vietnamese airspace when it vanished. No debris has been found anywhere near where it should have been.
Let us look at the possibilities. The first could be that something went seriously wrong in the cockpit – like an explosive break in a window. In that case, the pressure difference would suck people out of the plane. But the pilot would certainly not switch off the transponder, and if he did that by mistake, the plane’s debris would have been found by now.
The next possibility is that the plane had a catastrophic power failure. Aircraft manufacturers add layers of protection in terms of generating power from the jet engines, and having rechargeable batteries in parallel circuits etc. So, the probability that all electrical systems failed simultaneously is also rather low. Moreover, in this case as well, the aircraft would have dived into the water, leaving behind enough debris on the surface.
We know the pilot was not only experienced, but also an avid lover of aircrafts, and had set up a flight simulator in his house to practice on holidays. So, it is unlikely that he was not fully prepared to tackle a large variety of possible failures.
The only thing that seems to be rationally possible is that the disappearance had something to do with the fact that it was night, and the pilot was in one of the darkest night spaces in the world. In that case, if the navigational equipment fails, the pilot can become seriously disoriented as he has no landmarks to judge his location. Since he was away from any air traffic controllers, he would have had to rely on his wits. In such a case, the slightest of errors can take the plane off course in a significant manner. There are indications that the plane did change direction, apparently after its transponders stopped, as seen by the Malaysian military radar.
If this is indeed the case, given that it was a pitch dark night, the plane was over the sea and fuelled for a truly long haul, it could have gone hundreds of kilometres off course while the pilot searched for an airport or air traffic controllers who could help him land the plane. At some stage then, once he ran out of fuel, he would have crashed. In the days of GPS and accurate location trackers, this is improbable but not impossible and as Sherlock Homes would say, when you have eliminated the impossible, whatever remains, however improbable, must be the truth.
In the past, an aircraft had become depressurised over Greece and everyone was rendered unconscious. The plane went on to fly several hundred kilometres off course before crashing when fuel ran out. However, since then, aircraft manufacturers have ensured such problems do not arise or cripple an aircraft.
So, the mystery of MH370 deepens. Catastrophic failure at the place where the plane should have been is clearly not tenable. The only rational explanation seems to be that the pilot, losing power, became disoriented in a dark night over the sea, in an area poorly covered for civilian aircraft support, and while trying to seek help, took the plane to it its doom. That seems to be the only rational possibility – but then there are people who will talk of alien abductions…
Dr Mayank Vahia is a scientist working at the Tata Institute of Fundamental Research since 1979. His main fields of interest are high-energy astrophysics, mainly Cosmic Rays, X-rays and Gamma Rays. He is currently looking at the area of archeo-astronomy and learning about the way our ancestors saw the stars, and thereby developed intellectually. He has, in particular, been working on the Indus Valley Civilisation and taking a deeper look at their script.