A circle with a radius of 4,000 kilometres encompasses an area of roughly 50 million square km. This is about as much as the land area of the United States, Russia, Canada, China and Brazil combined. The missing Malaysian Airlines flight, MH370, disappeared somewhere within a circle of those dimensions.
The disappearance must have been deliberate. Sudden catastrophe is not a possibility. That Boeing 777 flew for at least seven hours without any attempt at communication. It did not try to land at any of the many airports in range. Somebody was in charge, given many changes in course and altitude across some of the world's busiest sea routes and air routes.
A fortnight after the flight vanished on March 8, there is little data in public domain. Airliners communicate via radio, automated transponder and manual-plus-automated aircraft communications addressing and reporting system (ACARS). The last automated ACARS report was at 0107 Malaysian Standard Time (MST is eight hours ahead of GMT). The last voice message was at 0119. The last transponder signal was at 0121. Malaysian radar lost contact at 0215.
Transponders use automated communications with air traffic control systems. They receive signals from ground-based radar and reply with so-called squawk codes to identify the aircraft. The transponder was switched off at 0122.
ACARS automatically transmits engine data via satellites (the 777 uses Rolls Royce engines) every 30 minutes during a flight. Pilots may also manually send text ACARS messages. ACARS pings satellites, "handshaking" to establish connection with a satellite, before transmission or reception. The messaging can be switched off. But the pinging cannot.
The last ACARS message was sent 12 minutes before the last voice communication. ACARS continued to ping satellites until 0811, over seven hours later. Pings don't carry location information. But if the same ping is received at two or more satellites, the difference in reception times can be used to triangulate rough location. As of now, search is focused off West Australia where satellites have picked up signs of debris in the ocean.
The aircraft passed through the airspace of many countries. Radar coverage has gaps everywhere and a low-flying aircraft may not be picked up. But it takes a smart, experienced pilot to run the gauntlet of multiple radar systems. Again, this seems to be deliberate evasion. (Thailand's radar system may have picked up MH370, but it was not noticed in real time.)
Aircraft also have "black boxes", which are actually Day-Glo orange in colour. The flight data recorder records a minimum of 88 different flight variables, and the cockpit voice recorder records voice communications. These can withstand big explosions and they are waterproof. Data from these could help solve the mystery. The flight data recorder and the cockpit voice recorder send out beacon location signals for 30 days if the plane crashes, but the beacon range is only 25 km.
Conspiracy theories are natural. The missing 777 could have been hijacked for use in a terrorist attack on a target in any of 14 nations. It may be in a secret location, refuelled for some nefarious purpose. Some dedicated conspiracy theorists assert that the search involving 26 nations is a sham, and secret negotiations are on with hijackers. My favourite is that this disappearance was arranged by the "military-industrial complex" to boost sales of new-generation radar.
Due to the terror implications, this can't just be written off, unlike mysterious disappearances in earlier eras. It will force reviews of airspace and airline security. The Indian Navy is unlikely to continue switching off its Andaman radars every night, as it blithely admitted to doing. ACARS may be reprogrammed to continuously stream location data. Manual switches, which allow pilots to shut down transponders and ACARS, may be disabled.
Massive investments on security since 9/11, coupled to modern aircraft technology, have made disappearances like this very rare. But MH370 emphasises that no security system is really secure and technology can always be bypassed by someone who's smart enough.
Disclaimer: These are personal views of the writer. They do not necessarily reflect the opinion of www.business-standard.com or the Business Standard newspaper
