News French plane lost over Atlantic

[Urwumpe]

LOL...no heaters? Do you think bringing out a ice-cold probe into weather that just froze your other probes will do you anything good?

Again, the solution is having proper Watts at the pitot heaters and not saving money by having weaker heaters there.

Also, the maintenance messages had been a blessing, because otherwise, the plane would have been just lost, without a trace. Maybe after some weeks, some wreckage would be washed ashore.

 

[Keatah]

LOL...no heaters? Do you think bringing out a ice-cold probe into weather that just froze your other probes will do you anything good?

Huh? I never said no heaters. The backup tube sits inside a tiny trapdoor, consuming no power.

If the backup tube is needed, the door opens and the tube is deployed into the airstream. Any engineer would design this backup pitot with a heater too. And you turn on the heater just before deployment.

 

[Urwumpe]

Why then have it at all? Can you explain this to me?

Lets assume, for the sake of keeping the thread sane, that invisible gnomes stealing the pitot tubes are impossible. How much does this mechanism help against superfreezing rain for example?

 

[Keatah]

This is very simple.

When the other pitot tubes have frozen up they are no longer useful, right? right..

You then deploy the backup tube. The backup tube is clean and has no ice since it has been "hiding" inside the aircraft body. Till now. Now you have a new, fresh, ice-free, unclogged air probe, ready to work.

Now, if for some reason this one freezes up too, you could always calculate airspeed from the RAT. Or why not measure how much force is required to deflect a flap or other control surface? From that you could get a rough estimate of airspeed.

The best solution would be to prevent them from freezing in the first place. So why not crank up the heater power? Or why not do a reverse flush? Just blast some bleed air into the tube and anything inside there would be pushed out.

 

[Evil_Onyx]

This is very simple.

When the other pitot tubes have frozen up they are no longer useful, right? right..

You then deploy the backup tube. The backup tube is clean and has no ice since it has been "hiding" inside the aircraft body. Till now. Now you have a new, fresh, ice-free, unclogged air probe, ready to work.

Now, if for some reason this one freezes up too, you could always calculate airspeed from the RAT. Or why not measure how much force is required to deflect a flap or other control surface? From that you could get a rough estimate of airspeed.

The best solution would be to prevent them from freezing in the first place. So why not crank up the heater power? Or why not do a reverse flush? Just blast some bleed air into the tube and anything inside there would be pushed out.

Assuming your backup door is not frozen closed or rips some of the aircrafts skin off when it deploys, your cold new pitot tube has seconds to warm up to prevent it from iceing, and in most cases it would be deployed strait in to cold air and freeze in no time at all. Then there is the the weight issue, how much is the system plus wireing/pipeing going weight and where are you going to put it? I don't think there is that much space on most Airliners for the system (at least not in the nose or around the cotpit where it would need to be).

And why have the system at all when it would be only used if 3 or 4 other similar systems have failed?

you could always calculate airspeed from the RAT.

On all the RAT systems I've seen, have a governor to prevent over pressuring the hydrolic lines.

why not measure how much force is required to deflect a flap or other control surface?

That force changes depending on AoA and other factors, which you probably wont get information on if your pitot tubes are not working.

I could go on....

 

[Turbinator]

Good read on how they found the plane:
(it is in English)

http://www.bea.aero/en/enquetes/flight.af.447/note.from.bea.director.end.phase4.pdf

 

[Notebook]

Brazil Air France crash: Flight recorder found empty

http://www.bbc.co.uk/news/world-europe-13218021

N.

 

[Urwumpe]

Yeah, sadly, but it is just one of the installed recorders, also there is still a good chance to find the interior of the recorder in a readable state.

 

[Notebook]

Hope so, they are putting some real effort into this search.

N.

 

[Urwumpe]

Hope so, they are putting some real effort into this search.

N.

Finally, after initially searching 10 NM further east without a good reason why.

 

[Suzy]

One of two flight recorders recovered. Not yet known if it will be readable.

 

[NukeET]

One of two flight recorders recovered. Not yet known if it will be readable.

Hope so.

 

[Turbinator]

The investigation team localized and identified the Cockpit Voice Recorder (CVR) at 21h50 UTC on Monday 2 May, 2011. It was raised and lifted on board the Ile de Sein by the Remora 6000 ROV at 02 h 40 UTC this morning, on Tuesday 3rd May, 2011.

 

[Suzy]

NYT article: "What Happened to Air France Flight 447?"

 

[Quick_Nick]

I heard at least one body has been recovered. (unless I misunderstood NPR's story)

 

[Keatah]

Why are these things shaped like cylinders? And what is the smaller cylinder on the end, the silverish-colored one..?

And what is the bronze-colored "tool" the dude is playing with?

Cool stuff. I didn't have much luck finding the engineering and design philosopies of flight recorders, testing methods and capabilities. Ideas?

 

[Urwumpe]

And what is the bronze-colored "tool" the dude is playing with?

Looks like a manifold to fill something into the tank.

 

[Turbinator]

ICAO Annex 6 document has Flight Data Recorder standards.

 

[Weirdo Earthtorch]

Why are these things shaped like cylinders? And what is the smaller cylinder on the end, the silverish-colored one..?

And what is the bronze-colored "tool" the dude is playing with?

The small cylinder is, I understand, the 'pinger' module. Looking closely at the pic, the tool looks like a good old-fashioned stamp, presumably applying the judicial seal to the storage vessel.

 

[garyw]

The small cylinder is, I understand, the 'pinger' module. Looking closely at the pic, the tool looks like a good old-fashioned stamp, presumably applying the judicial seal to the storage vessel.

If you zoom in you can see what looks like red ink underneath it so I agree it's a seal of some sort to make sure that the recorder isn't tampered with enroute to France.