Missing Flight MH370: Are there really unmonitored black spots? Your questions answered


Travel Correspondent

10 days after Malaysia Airlines flight MH370 from Kuala Lumpur to Beijing was lost, the range of possibilities to explain its disappearance is still extremely wide. We invited readers to pose questions about the lost Boeing 777- and the wider implications of the biggest mystery in 21st-century aviation.

Given the level of satellite coverage, are there really unmonitored black spots?

Sarah Johns

Many travellers have reacted with dismay or astonishment to the revelation that it is apparently so difficult to track the movements of a 250-ton aircraft with 239 people aboard. To understand why it is tricky, first look at the needs of individual nations. Governments are interested in knowing about aircraft flying overhead or approaching their airspace. In the US, Europe and some other parts of the world, control is maintained at all times. At the other extreme, parts of sub-Saharan Africa have extremely patchy coverage. South East Asia is busy in aviation terms, but air-traffic management is not as effective as in Europe. The main way to detect an aircraft whose transponder (which normally transmits identification details) is turned off is through “primary radar”. This is Second World War technology that sweeps the sky with a high-energy electromagnetic beam and registers any reflections. An unexplained radar “blip” in the early hours of the morning may go unnoticed, especially if it goes away quickly, or at least may not prompt a reaction.

From the airlines’ perspective, a relatively primitive reporting system has worked remarkably well over the decades: duty rooms note the departure time, estimate the arrival time, and ask the crew to report their position by radio at regular intervals. This could be replaced by a much more effective satellite reporting system, though it would prove expensive to retro-fit existing aircraft.

There is effectively saturation coverage by satellite of the surface of the earth, albeit with some weakness around the poles (not relevant in this case). Satellites fitted with cameras are routinely able to see aircraft in flight – to see some snapped serendipitously, just search for “Google Earth planes flying”. But in the hours of darkness, this would be virtually impossible.

I don't understand from the "pings" why the aircraft can be in two possible corridors in relation to the satellite?

James Taylor

After the main communication systems were turned off aboard MH370, one channel remained open: a periodic “handshake” between the aircraft and an Inmarsat communications satellite in geostationary orbit 22,250 miles above the Indian Ocean. The last was at 8.11am, local time. From the time that it took the responding “ping” to reach the satellite, it is possible to compute the distance from the satellite. Then, elementary geometry comes into play: draw a circle on the surface of the earth showing all the points that match that distance. The circle has a circumference of about 18,000 miles, but most of it can be disregarded because the limited range of the plane from its last known point. In addition, the Malaysian authorities chose to rule out a 1,200-mile segment between the two arcs, though the logic for doing so seems flawed: they say it takes into account the minimum flying speed of the jet, though this interpretation appears to ignore the possibility that the aircraft could zig-zag or fly around in circles.

The aircraft is unlikely to be exactly on one or other arc, since in the time since that “handshake” was registered it could have flown 250 miles in any direction.

Do cabin crew have no way to signal an “incident”? Perhaps they should after this

Michael Choo

Cabin crew have access to emergency locator transmitters, but these are electronic distress beacons designed to be used in the event of a ditching at sea or forced landing rather than in flight. There is no publicly available evidence that one was activated aboard MH370.

What will the impact be on airline security?


The long-term effects will depend upon what more we learn about the fate of MH370. But already the aviation community is looking at two possible areas of intensified security, one affecting passengers and the other pilot.

The revelation that two passengers were travelling on stolen passports may lead to a requirement that details of travel documents are compared against a central database of missing passports. And if it is found that either an intruder to the flight deck or one of the pilots was responsible for the disappearance, there may be calls for an air marshal to be seated on the cockpit to deter unwanted intrusions – and to keep an eye on the captain and first officer.

Either move would prove expensive, and the latter would be strongly resisted by many pilots.

Weren't there reports of passengers’ mobiles still ringing? Stories dismissed but now credible.


Early on in the hunt for the aircraft, some reports suggested that passengers’ mobiles were ringing out rather than going straight to voicemail – but it appears that this was simply due to the phone networks' configuration. Indeed, one of the most troubling aspects of this case is the absence of reliable evidence of contact between people on the plane and their relatives on the ground. If and when the passengers became aware of a threat, a natural response would be to attempt to contact family using mobile phones. Although voice calls from a plane at 30,000 feet do not usually work, SMS messages sometimes do. In their absence, it is difficult to conclude other than the passengers were prevented from using them, or that the plane was flying over the sea well out of range of mobile-phone masts.

A friend bought a Malaysian Airlines ticket before this happened. Now she's very worried indeed. Is there need to be?

John Brady

No. Flying on commercial jets remains an astonishingly safe form of transport. The accident-free record of Britain’s airlines over the past 25 years is the envy of the world, but other major carriers – including Malaysia Airlines – are also extremely safe. The most significant risk of any trip to South East Asia is a road accident.

Life and Style
A teenager boy wakes up.
Life and Style
It is believed that historically rising rates of alcohol consumption have contributed to the increase
food + drink
An Apple iPhone 6 stands on display at the Apple Store
businessRegulators give iPhone 6 and 6 Plus the green light
Arts and Entertainment
Critics say Kipling showed loathing for India's primitive villagers in The Jungle Book
filmChristopher Walken, Bill Murray, Scarlett Johanssen Idris Elba, Andy Serkis, Benedict Cumberbatch, Cate Blanchett and Christian Bale
Have you tried new the Independent Digital Edition apps?
Life and Style
Britain's internet habits have been revealed in a new survey
Life and Style
Playing to win: for Tanith Carey, pictured with Lily, right, and Clio, even simple games had to have an educational purpose
lifeTanith Carey explains what made her take her foot off the gas
Arts and Entertainment
Arts and Entertainment
The White Sails Hospital and Spa is to be built in the new Tunisia Economic City.
architectureRussian billionaire designs boat-shaped hospital for new Dubai-style Tunisia Economic City
Arts and Entertainment
Life and Style
Arts and Entertainment
A still from Duncan Campbell's hour-long film 'It for Others'
Turner Prize 2014
Life and Style
food + drink
Arts and Entertainment
Tony Hadley in a scene from ‘Soul Boys Of The Western World’
musicSpandau Ballet are back together - on stage and screen
ebookHow to enjoy the perfect short break in 20 great cities
Life and Style
Bearing up: Sebastian Flyte with his teddy Aloysius in Brideshead Revisited
lifePhilippa Perry explains why a third of students take a bear to uni
Arts and Entertainment
Sir Alan Sugar appearing in a shot from Apprentice which was used in a Cassette Boy mashup
artsA judge will rule if pieces are funny enough to be classed as parodies
Arts and Entertainment
Independent Travel Videos
Independent Travel Videos
Simon Calder in Amsterdam
Independent Travel Videos
Simon Calder in Giverny
Independent Travel Videos
Simon Calder in St John's
Independent Travel Videos
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

ES Rentals

    iJobs Job Widget
    iJobs Travel

    Management Accountant

    28,000 to 32,000 per annum: Accountancy Action: Our client, a hospitality busi...

    Food and Beverage Cost Controller

    18,000 to 20,000 per annum: Accountancy Action: Our fantastic leisure client i...

    Marketing Analyst / Marketing Executive

    £20 - 24k: Guru Careers: A Marketing Analyst / Marketing Executive is needed t...

    IT Administrator - Graduate

    £18000 Per Annum: Clearwater People Solutions Ltd: ***EXCELLENT OPPORTUNITY FO...

    Day In a Page

    Isis is an hour from Baghdad, the Iraq army has little chance against it, and air strikes won't help

    Isis an hour away from Baghdad -

    and with no sign of Iraq army being able to make a successful counter-attack
    Turner Prize 2014 is frustratingly timid

    Turner Prize 2014 is frustratingly timid

    The exhibition nods to rich and potentially brilliant ideas, but steps back
    Last chance to see: Half the world’s animals have disappeared over the last 40 years

    Last chance to see...

    The Earth’s animal wildlife population has halved in 40 years
    So here's why teenagers are always grumpy - and it's not what you think

    Truth behind teens' grumpiness

    Early school hours mess with their biological clocks
    Why can no one stop hackers putting celebrities' private photos online?

    Hacked photos: the third wave

    Why can no one stop hackers putting celebrities' private photos online?
    Royal Ballet star dubbed 'Charlize Theron in pointe shoes' takes on Manon

    Homegrown ballerina is on the rise

    Royal Ballet star Melissa Hamilton is about to tackle the role of Manon
    Education, eduction, education? Our growing fascination with what really goes on in school

    Education, education, education

    TV documentaries filmed in classrooms are now a genre in their own right
    It’s reasonable to negotiate with the likes of Isis, so why don’t we do it and save lives?

    It’s perfectly reasonable to negotiate with villains like Isis

    So why don’t we do it and save some lives?
    This man just ran a marathon in under 2 hours 3 minutes. Is a 2-hour race in sight?

    Is a sub-2-hour race now within sight?

    Dennis Kimetto breaks marathon record
    We shall not be moved, say Stratford's single parents fighting eviction

    Inside the E15 'occupation'

    We shall not be moved, say Stratford single parents
    Air strikes alone will fail to stop Isis

    Air strikes alone will fail to stop Isis

    Talks between all touched by the crisis in Syria and Iraq can achieve as much as the Tornadoes, says Patrick Cockburn
    Nadhim Zahawi: From a refugee on welfare to the heart of No 10

    Nadhim Zahawi: From a refugee on welfare to the heart of No 10

    The Tory MP speaks for the first time about the devastating effect of his father's bankruptcy
    Witches: A history of misogyny

    Witches: A history of misogyny

    The sexist abuse that haunts modern life is nothing new: women have been 'trolled' in art for 500 years
    Shona Rhimes interview: Meet the most powerful woman in US television

    Meet the most powerful woman in US television

    Writer and producer of shows like Grey's Anatomy, Shonda Rhimes now has her own evening of primetime TV – but she’s taking it in her stride
    'Before They Pass Away': Endangered communities photographed 'like Kate Moss'

    Endangered communities photographed 'like Kate Moss'

    Jimmy Nelson travelled the world to photograph 35 threatened tribes in an unashamedly glamorous style