French passenger jet gone missing from radar screens........
Discussion
Surprises me that there isnt sufficient radar coverage to get a better idea of where it went down.
I think airliners should also carry radar sets, with the data sent to a remote station where the results could be overlapped to form effectively a corridor of full radar coverage in the air along busier routes.
I think airliners should also carry radar sets, with the data sent to a remote station where the results could be overlapped to form effectively a corridor of full radar coverage in the air along busier routes.
My girlfriend is off duty but just phoned the area control centre and a controller on duty said that the aircraft apparently made a PAN PAN call over Dakar before contact was lost.
ETA Now just heard the PAN PAN was made 3.5 hours from take off
ETA Now just heard the PAN PAN was made 3.5 hours from take off
Edited by Driller on Monday 1st June 12:50
Driller said:
Eric Mc said:
It disappeared just off the cost of Brazil so would not have been anywhere near France to appear on French or other European radar screens.
I don't know why there is so much talk about transponders. Loss of a transponder signal would not, per se, mean loss of the aircraft.
An aeroplane will be tracked on a radar screen because the radio waves broadcast from the radar dish bounce off the aircraft and are received by the radar dish. The return signal will show up as a blip on the controller's radar screen. This basic radar is called Primary Radar and the transponder on board the aircraft is not needed for this primary radar. A skilled controller can track an aircraft (with some limitations) purely using Primary Radar. A transponder is not essential to identify and track an aircraft.
There is a second radar system called Secondary Surveilland Radar (SSR). This is beamed at the aircraft and the transponder on board the aircaft picks up the signal, amplifies it and re-broadcasts it back to the Secondary Radar antenna. The transponder allows the radar screen to show a flight designator (such as a registration letter/number or a flight number) to "affix" itself to the radar blip. The transponder also transmits height information. SSR allows a controller easier identification and tracking of a radar return.
If the aircraft seemingly did not transmit a distress call using voice communications, this indicates a sudden and catastrophic failure of the aircraft. This usally means a complete and sudden failure of (say) a wing or other part of the main structure - such as the fuselage. A fuselage failure can occur if the fuselage is breached for some reason causing explosive decompression and possiblty complete breakup of the aircraft.
A number of airliners which have been lost in this manner have been the victims of bomb attacks. Examples are an Air India 747 off the coast orf Ireland in 1985, the Pan Am Lockerbie 747 in 1988 and an Air Inter (French) DC-10 in 1984.
Air Inter was absorbed into Air France about ten years ago so French airliners have been targetted before.
My girlfriend is off duty but just phoned the area control centre and a controller on duty said that the aircraft apparently made a PAN PAN call over Dakar before contact was lost.I don't know why there is so much talk about transponders. Loss of a transponder signal would not, per se, mean loss of the aircraft.
An aeroplane will be tracked on a radar screen because the radio waves broadcast from the radar dish bounce off the aircraft and are received by the radar dish. The return signal will show up as a blip on the controller's radar screen. This basic radar is called Primary Radar and the transponder on board the aircraft is not needed for this primary radar. A skilled controller can track an aircraft (with some limitations) purely using Primary Radar. A transponder is not essential to identify and track an aircraft.
There is a second radar system called Secondary Surveilland Radar (SSR). This is beamed at the aircraft and the transponder on board the aircaft picks up the signal, amplifies it and re-broadcasts it back to the Secondary Radar antenna. The transponder allows the radar screen to show a flight designator (such as a registration letter/number or a flight number) to "affix" itself to the radar blip. The transponder also transmits height information. SSR allows a controller easier identification and tracking of a radar return.
If the aircraft seemingly did not transmit a distress call using voice communications, this indicates a sudden and catastrophic failure of the aircraft. This usally means a complete and sudden failure of (say) a wing or other part of the main structure - such as the fuselage. A fuselage failure can occur if the fuselage is breached for some reason causing explosive decompression and possiblty complete breakup of the aircraft.
A number of airliners which have been lost in this manner have been the victims of bomb attacks. Examples are an Air India 747 off the coast orf Ireland in 1985, the Pan Am Lockerbie 747 in 1988 and an Air Inter (French) DC-10 in 1984.
Air Inter was absorbed into Air France about ten years ago so French airliners have been targetted before.
thehawk said:
Driller said:
Eric Mc said:
It disappeared just off the cost of Brazil so would not have been anywhere near France to appear on French or other European radar screens.
I don't know why there is so much talk about transponders. Loss of a transponder signal would not, per se, mean loss of the aircraft.
An aeroplane will be tracked on a radar screen because the radio waves broadcast from the radar dish bounce off the aircraft and are received by the radar dish. The return signal will show up as a blip on the controller's radar screen. This basic radar is called Primary Radar and the transponder on board the aircraft is not needed for this primary radar. A skilled controller can track an aircraft (with some limitations) purely using Primary Radar. A transponder is not essential to identify and track an aircraft.
There is a second radar system called Secondary Surveilland Radar (SSR). This is beamed at the aircraft and the transponder on board the aircaft picks up the signal, amplifies it and re-broadcasts it back to the Secondary Radar antenna. The transponder allows the radar screen to show a flight designator (such as a registration letter/number or a flight number) to "affix" itself to the radar blip. The transponder also transmits height information. SSR allows a controller easier identification and tracking of a radar return.
If the aircraft seemingly did not transmit a distress call using voice communications, this indicates a sudden and catastrophic failure of the aircraft. This usally means a complete and sudden failure of (say) a wing or other part of the main structure - such as the fuselage. A fuselage failure can occur if the fuselage is breached for some reason causing explosive decompression and possiblty complete breakup of the aircraft.
A number of airliners which have been lost in this manner have been the victims of bomb attacks. Examples are an Air India 747 off the coast orf Ireland in 1985, the Pan Am Lockerbie 747 in 1988 and an Air Inter (French) DC-10 in 1984.
Air Inter was absorbed into Air France about ten years ago so French airliners have been targetted before.
My girlfriend is off duty but just phoned the area control centre and a controller on duty said that the aircraft apparently made a PAN PAN call over Dakar before contact was lost.I don't know why there is so much talk about transponders. Loss of a transponder signal would not, per se, mean loss of the aircraft.
An aeroplane will be tracked on a radar screen because the radio waves broadcast from the radar dish bounce off the aircraft and are received by the radar dish. The return signal will show up as a blip on the controller's radar screen. This basic radar is called Primary Radar and the transponder on board the aircraft is not needed for this primary radar. A skilled controller can track an aircraft (with some limitations) purely using Primary Radar. A transponder is not essential to identify and track an aircraft.
There is a second radar system called Secondary Surveilland Radar (SSR). This is beamed at the aircraft and the transponder on board the aircaft picks up the signal, amplifies it and re-broadcasts it back to the Secondary Radar antenna. The transponder allows the radar screen to show a flight designator (such as a registration letter/number or a flight number) to "affix" itself to the radar blip. The transponder also transmits height information. SSR allows a controller easier identification and tracking of a radar return.
If the aircraft seemingly did not transmit a distress call using voice communications, this indicates a sudden and catastrophic failure of the aircraft. This usally means a complete and sudden failure of (say) a wing or other part of the main structure - such as the fuselage. A fuselage failure can occur if the fuselage is breached for some reason causing explosive decompression and possiblty complete breakup of the aircraft.
A number of airliners which have been lost in this manner have been the victims of bomb attacks. Examples are an Air India 747 off the coast orf Ireland in 1985, the Pan Am Lockerbie 747 in 1988 and an Air Inter (French) DC-10 in 1984.
Air Inter was absorbed into Air France about ten years ago so French airliners have been targetted before.
Driller said:
My girlfriend is off duty but just phoned the area control centre and a controller on duty said that the aircraft apparently made a PAN PAN call over Dakar before contact was lost.
ETA Now just heard the PAN PAN was made 3.5 hours from take off
Sad news indeed, though the pistonhead jungle drums are always impressive getting the news first.ETA Now just heard the PAN PAN was made 3.5 hours from take off
Edited by Driller on Monday 1st June 12:50
So do these planes have live telemetrics sent back to their base? If Air France received an automatic message that there was a short circuit and then knew it flew into turbulence 15 minutes later they must have been monitoring it somehow.
http://www.reuters.com/article/topNews/idUSTRE5501...
http://www.reuters.com/article/topNews/idUSTRE5501...
It sounds like electrical problems were occuring - but they may have been a symptom of a more serious underlying problem - like an engine failure, for instance.
The A330 is a Fly By Wire airliner so is very dependent on good electrical reliability to ensure the flight control computers and instrumentation work properly.
A total electrical failure is very, very unlikely and it will take a long hard search to get to the bottom of what went wrong.
First they need to locate where thge aircraft went down.
The A330 is a Fly By Wire airliner so is very dependent on good electrical reliability to ensure the flight control computers and instrumentation work properly.
A total electrical failure is very, very unlikely and it will take a long hard search to get to the bottom of what went wrong.
First they need to locate where thge aircraft went down.
ref Eric's post above:
Hardly any civil radar units use Primary radar these days for regular taffic management purposes. It's almost all done using Secondary returns. I'm sure Euroboy or a colleague of his could expound on that.
Weather over that part of the Atlantic last night/early this morning was pretty crappy(Embedded CBs up to 52000').
This looks bad. It's pretty much impossible to lose all contact unless you have a total electrical failure. Comms over that stretch of water are on HF with Atlantico, Dakar or Sal depending on where you are. There is normally a period of VHF Comms/Radar cover with Sal as you pass over the Cap Verdes, and then onwards towards the Canaries.
It's not uncommon to lose contact on HF if the weather is bad (too much static and interference from CBs), and then you always have the ability to do relays with other aircraft who are in radio contact with ATC. Failing that, there's SatCom (which i'm certain the A330 has) - many times I've telephoned Gander/Shannon/Tripoli/Algiers when all other means of communication don't seem to work. Once I've even had Gander call me on the aircraft SatCom to pass a clearance when they couldn't get hold of us on HF.
Whatever has happened to them - there is nil chance of the aeroplane still being in the air at this time.
Hardly any civil radar units use Primary radar these days for regular taffic management purposes. It's almost all done using Secondary returns. I'm sure Euroboy or a colleague of his could expound on that.
Weather over that part of the Atlantic last night/early this morning was pretty crappy(Embedded CBs up to 52000').
This looks bad. It's pretty much impossible to lose all contact unless you have a total electrical failure. Comms over that stretch of water are on HF with Atlantico, Dakar or Sal depending on where you are. There is normally a period of VHF Comms/Radar cover with Sal as you pass over the Cap Verdes, and then onwards towards the Canaries.
It's not uncommon to lose contact on HF if the weather is bad (too much static and interference from CBs), and then you always have the ability to do relays with other aircraft who are in radio contact with ATC. Failing that, there's SatCom (which i'm certain the A330 has) - many times I've telephoned Gander/Shannon/Tripoli/Algiers when all other means of communication don't seem to work. Once I've even had Gander call me on the aircraft SatCom to pass a clearance when they couldn't get hold of us on HF.
Whatever has happened to them - there is nil chance of the aeroplane still being in the air at this time.
According to one of my French speaking colleagues, the French media are reporting that the plane sent out an automated distress message after losing all electrical power following flying through an electrical storm.
Very curious, as if true, I would have thought that the plane had backup systems that backup backup systems etc.
Very curious, as if true, I would have thought that the plane had backup systems that backup backup systems etc.
Edited by schmalex on Monday 1st June 13:19
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