A few Q&A by Guy Walter;
You can read the full article here:GUY WALTERS offers answers to mysteries surrounding Malaysian Airlines flight MH370 | Mail Online
1. How could there be reports from relatives that some of the passengersâ phones are still ringing?
If the phones are ringing, that could mean they are on land and near a mobile cell site. If that is the case, it seems bizarre nobody noticed the plane land or crash.
However, experts doubt the phones are ringing. If you call someone whose phone has no charge, it sounds as though the phone is ringing, before you go through to the voicemail.
âThe phones definitely wonât be working,â says Professor William Webb, a Fellow of the Royal Academy of Engineering.
âThey will be underwater, out of coverage and by this time out of battery.â
2. One theory says the plane was escorted to a secret location by Vietnamese fighter jets. Could that happen?
The Boeing 777 is a large aeroplane â 242ft long, with a 200ft wingspan. Itâs difficult for an aircraft of that size to land somewhere unusual without people spotting it.
âA 777 needs a runway that is a good 2,000m (2,180 yards) long,â says Robin Durie, an experienced commercial pilot.
âYou donât just land a plane like that in a clearing in the jungle.â
3. Why is the âblack boxâ not revealing the planeâs location?
The black box, or flight data recorder, stores much of the information about the flight, including the conversations of the pilots.
The boxes are almost indestructible, and resilient to impact and heat.
After a plane has crashed, the black box transmits a homing beacon, but the range is only 2,000 or 3,000 yards, and even less if it is deep underwater.
âA device such as a black box doesnât make the aircraft safer,â says Mr Durie. âThey just tell you where its wreckage is. But airlines are very reluctant to add numerous pieces of technology, as they are expensive to buy and maintain.â
There has recently been discussion within the industry about the possibility of sending data from aircraft during their flights to a remote server, thereby negating the need for a black box, but this is regarded as being too expensive.
4. Why can no debris or wreckage be found? It seems inconceivable that an aircraft of this size could leave no trace.
âI find that very odd as well,â says Mr Durie. âAeroplanes are not just made from metal, and there are lots of parts of them, such as seats and luggage, that can float.
âEven after the Air France crash over the Atlantic in June 2009, a whole piece of rudder was found on the water.â
However, Mr Durie also cites the example of the 2005 crash of Helios Airways Flight 522, which flew on its own for almost three hours after the crew members were incapacitated by a lack of oxygen. It crashed near Athens, killing all on board.
With several hours of fuel, it is possible that MH370 crashed hundreds of miles away from its last known location.
5. Are there areas of the world where a plane can just âslip off the radarâ?
Plenty. Tracts of Africa, much of the interior of Russia, jungles in Malaysia, for example.
Modern airliners use transponders, which transmit a unique four-digit code that is identified with the flight. It is these codes that are picked up by air traffic controllers and used to locate the aircraft.
If the transponder stops transmitting â either because it is turned off or as the result of a sudden, catastrophic incident â then over many parts of the globe, the plane would be invisible to air traffic controllers.
6. Why was no distress signal sent?
âIf you have some form of emergency, then the first thing the pilot does is to change the transponder code,â says Mr Durie. âIf you change your code to 7500, that means you have been hijacked.
âBack at Air Traffic Control, a big red box appears around your flight, and people take notice very quickly.â
In the event of a serious malfunction, the code changes to 7600, and in a Mayday situation, to 7700.
Changing the code is as quick as entering your PIN on a cash machine.
âThe fact that the transponder code didnât change suggests to me that whatever happened, happened really quickly,â says Mr Durie. âThis might mean an explosion.â
7. A pilot on another aircraft claims to have made contact with MH370 shortly before it went missing â but all he heard was mumbling. What could this mean?
'All pilots have frequencies that we use to chat on,â says Mr Durie. âOften this is company traffic, when crew from the same carrier are simply talking to each other.
âTechnically, itâs not legal, but the practice is widespread and many pilots tune into the easy-to-remember VHF band of 123.45.â
If another pilot heard some mumbling, it is possible that it was chat coming from another pilot on the same frequency. However, it could have been a crew member from MH370.
âThe mumbling suggests to me that the pilot was passing out from a lack of oxygen,â says Mr Durie, âwhich could mean that the aircraft had suffered an explosive decompression, such as a window popping out, or a small hole appearing in the fuselage.â
8. Would it be possible for a deranged or psychotic passenger to seize control and cause a disaster?
The door to the cockpit is locked, and can be opened only from the inside. However, large airliners carry an axe in a secret location in one of the galleys.
A fanatic who found the axe could break into the cockpit, but it is unlikely the axe could be found without the knowledge of the cabin crew.
9. Could the pilot have hijacked or deliberately crashed the aircraft?
Pilots have been known to hijack their own planes. One theory behind the crash of EgyptAir Flight 990 into the Atlantic in 1999 is that the Relief First Officer wanted to commit suicide.
âA pilot can turn off his transponder, thereby making his plane invisible to Air Traffic Control,â says Mr Durie.
âThen, if he takes control of the cockpit, he can fly where he wants â either somewhere to seek asylum, or horribly, to kill himself and all on board.â
[h=2]0. If the flight was downed by an explosion, why wasnât it captured on film by a US satellite?[/h]Not even the United States has the capability to record what happens everywhere in the world all the time.
If the plane did explode, then it is perfectly possible that the event would not have been captured by satellite.