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Old 31 May 2010, 03:57   #11
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Did any one see 'Disappearance of flight 447' docu last night? The Air France Airbus that crashed into the Atlantic last year. Scary stuff. Basically, if the 3 air speed pitots block through a phenomenon known as supercooled water, all the automated systems go down. If the pilots are not quick enough or well trained enough to recover airspeed immediately and whack the throttles forward,the plane will stall and fall out of the sky. Because modern airline pilots do very little stick flying, very few, apart from maybe ex-fighter pilots, are able to recover normal flight after an uncontrolled rapid decent.
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Old 31 May 2010, 06:40   #12
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I didn't but hopefully it will be on here at some point. Amazing if that caused it - pitot icing has been known about for years - I think it's a requirement for anything big to have heated pitots (and presumably three of them on that aircraft) to stop exactly that .... and I would have thought in this day and age an airliner was intelligent enough to watch a GPS speed and squawk if the readings didn't agree. I bet there are a few changes as a result, sadly too late for those on the flight
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Old 01 June 2010, 00:07   #13
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Aye and thats what annoys me .. where have we gone since then ? ,, nowhere !

IMVVHO from an engineering point of view, allowing it, and the concept to founder is a very backwards move
It does seem like aeronautical engineering has been rather stagnant for about the last 40 years. When was the last time someone walked on the moon?
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Old 01 June 2010, 07:36   #14
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I didn't but hopefully it will be on here at some point. Amazing if that caused it - pitot icing has been known about for years - I think it's a requirement for anything big to have heated pitots (and presumably three of them on that aircraft) to stop exactly that .... and I would have thought in this day and age an airliner was intelligent enough to watch a GPS speed and squawk if the readings didn't agree. I bet there are a few changes as a result, sadly too late for those on the flight
Apparently the pitots were heated but they had realised that the heaters were not really up to the job, and so Airbus (or was it Air France?) were in the middle of an upgrade programme. The flight 447 AB330 hadn't been upgraded!
Like you, I was sitting there thinking where's the GPS
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Old 01 June 2010, 07:52   #15
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Apparently the pitots were heated but they had realised that the heaters were not really up to the job, and so Airbus (or was it Air France?) were in the middle of an upgrade programme. The flight 447 AB330 hadn't been upgraded!
Like you, I was sitting there thinking where's the GPS
Airspeed & groundspeed could differ by a big ( I'd guess up to 100knts + ) at 40,000 feet and with no visual refs the recovery of any aircraft is very tough - relying on just instruments (which had failed) and airliners dont respond as well, or have the roll rates to sort out 'unusual attitudes' .

Dont get me wrongs its not ideal , but I really do think that any decent Western Airline commercial pilots are capable of recovering anything if it is physically possible. Remember these guys have been doing it a long time & are tested to extremes on a very regular basis.

Concorde is a differant animal - my phone has more computing power I am sure - hence why they didn't worry too much about the 'millenium bug' in it - no computers = no problems! Simple (realtively) systems and instruments etc - and used to fly much higher, so above most duff weather.
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Old 01 June 2010, 07:53   #16
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Squawk wont help, its a passive output for Air Traffic Control to show on radar displays.
GPS unfortunately is not used by the aircraft systems as a primary sourse of information, as the quality and consistancy is not yet good enough. There are still places and times around the globe where a GPS signal is not guarenteed.
However, had it been available and the pilots had the piece of mind to use it, it may have helped as a guide to the speed of the aircraft.
The GPS will only give you the speed over the ground and a readout in Kts. At high levels (FL290+) aircraft are flown with reference to the local speed of sound or Mach number. This is a percentage of the speed of sound according to the outside air temperature, so typically a large jet will fly at 0.84mach or 84% of the speed of sound. A GPS would not know what the outside air temp was and therefore not help.
For a jet at FL370, the difference between the stall speed and the max speed (VNE) can be as little as 15kts! Therefore even a small deviation can result in falling out the sky or damaging the airframe (and then falling out the sky).
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Old 01 June 2010, 08:00   #17
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Squawk wont help, its a passive output for Air Traffic Control to show on radar displays.
GPS unfortunately is not used by the aircraft systems as a primary sourse of information, as the quality and consistancy is not yet good enough. There are still places and times around the globe where a GPS signal is not guarenteed.
However, had it been available and the pilots had the piece of mind to use it, it may have helped as a guide to the speed of the aircraft.
The GPS will only give you the speed over the ground and a readout in Kts. At high levels (FL290+) aircraft are flown with reference to the local speed of sound or Mach number. This is a percentage of the speed of sound according to the outside air temperature, so typically a large jet will fly at 0.84mach or 84% of the speed of sound. A GPS would not know what the outside air temp was and therefore not help.
For a jet at FL370, the difference between the stall speed and the max speed (VNE) can be as little as 15kts! Therefore even a small deviation can result in falling out the sky or damaging the airframe (and then falling out the sky).
Steve

Really looking forward to my flight tomorrow!
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Old 01 June 2010, 08:23   #18
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Really looking forward to my flight tomorrow!
But don't worry - your more likely to die in the car on the way, or drown falling off a pontoon , be killed by the food, or a terrorist in the airport, run over in the car park etc etc

Me - I love flying ........
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Old 01 June 2010, 09:05   #19
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or a terrorist in the airport.
Me - I love flying ........
Algeria here I come!
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Old 01 June 2010, 09:21   #20
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But don't worry - your more likely to die in the car on the way, or drown falling off a pontoon , be killed by the food, or a terrorist in the airport, run over in the car park etc etc

Me - I love flying ........
Me too and I see some of the horrors that go on.

Put you practical head on, if the same number of people were killed in the air, as are killed on the roads every year in the UK, they would ban flying! But you dont think about getting in your car and driving everytime, do you?

Water and the air in can deal with, its terrafirma that kills ....
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