Air France jet vanishes

Speaking of Pitot blockage, I was with my brother in a rented Piper Arrow making IFR approach from 20 miles out in the fog when he lost airspeed indications. I don't know what he did to get us in but he was on the radio A LOT!.

We popped out right on the numbers. He said it was a plugged pitot later.

 

The pilot of whom you speak was a check pilot who, as requested, rode with three students who were doing practice IFR flights. They took off at night and were working thier way to the south west of Oregon in actual IFR. They lost all NavCom somewhere near Eugene and he took over from the girl who was flying. He knew the elevation of the coast range to the west so he headed out to the Pacific at a safe altitude and made a gradual let down until he could see the ocean and then headed east to intercept the coast. They flew south along the coast until they got to Coos Bay where they made a safe landing with an airplane that had been zapped by some sort of electrical anomaly.
Switches

 

I have really learnt a lot from this thread, its just a shame how it came about. I have always been interested in flying and started to get my licence a few years ago but ended up putting it on hold. I remember another airliner crashing because of a blocked pitot, i believe the plane had been standing for a while and it was not covered and some insects had entered.

16 Bodies found now according to the news, RIP

 

Unless they recover the CVR and FDR, we'll most likely never know the answer to that one.

 

Debris recovery pics.........

Looks like the vertical fin broke close to where the fin on the AA Airbus crash in NYC did.......and I'm not saying these incidents are related in any way either, that's beyond my knowledge.
Image Unavailable, Please Login
Image Unavailable, Please Login

 

I was afraid of something like this -

Look at the bottom trailing edge...

Of course, the claim could be made that this was just the result of the breakup, not the cause of the breakup.

But none of these fly very far without a vertical stabilizer.

 

The most glaring thing to me in that picture is that the attachment flange has no other structure from the fuselage still connected to it...it's clean! To me that indicates a clean break away from the fuselage.The trailing edge of the rudder shows that it could have translated aft and rotated backwards to sustain the damage that is evident. I'm no crash expert but that's what it looks like to me.
Switches

 

Forgive my stupid question, but why is the guy on the wing wearing nothing but a speedo? Wouldnt he freeze? This is truly a tragedy.

Chris

 

It's warm down there..........the water is quite nice actually.

Here's a graphic of where the tail looks like it seperated.

All pics taken from pprune.org..................
Image Unavailable, Please Login

 

I think the cut line in the picture is too high.
The fin is fore-shortened in picture because of the angle it was taken.
If it did break off at the point of the green line in the picture then the Red and Blue stripes on the tail would run right to the edge of the break.
If you look closely at the picture the stripes do not run all the way to the edge.
I think the break was closer to the fuselage than depicted in the picture.

 

Excuse, please, but in the first picture don't I see the blue stripes terminate into the white area of the web? In which case Mr. Parks is right, it may well have just snapped off right where it is bolted on just like the NYC crash...?

 

The photo of the fin in the first picture shows the entire fin assembly down to the mounting flange that can be seen with a swimmer near it.

 

Exactly. The current media wisdom is concentrating on an airspeed malfunction (of the indicators) due to "icing of the pitot tube(s)". Heated pitot tubes. At 35,000 feet.

I have two questions, and maybe this verges into the naive - if this plane is so heavily computerized, and so dependant on those computers and critical inputs thereof - isn't there some source of backup to the pitot input for airspeed?

For example, wouldn't the inertial guidance system "know" that the airspeed didn't just suddenly dissappear? How about GPS?

I know that for example an F-16 had two IAS pitots, and TWO angle of attack inputs (one for each wing), as well as G force devices, to work out the highly complex firing solutions and a pretty sophisticated computer system for the day to crunch the numbers. All of it had to agree to end up as display before the pilot's eyes.

I don't know. As horrible as it is to say (and it is horrible) I almost feel that I am reluctantly wishing for some kind of pilot error on this one. Edit to say that any alternative I can think of is even more horrible.

 

If you want to see a vertical fin on an airliner behave the way it's supposed too look at the video of the hijacked 767 hitting the water with the left wing tip and skidding into the water sideways. You can see the fin actually twisting the aft fuselage from the huge side loads that it's taking. It never came off even after it hit the water.
Switches

 

Stupid question: what gives that tail debris buoyancy? It is hollow and has an air pocket? Is it filled with some sort of buoyant material? While I would expect to see floating debris in the nature of seat cushions, I wouldn't expect to see structural debris. I would have expected it to be on the sea floor.

CW

 

I think a lot of pieces were breaking off this aircraft before it impacted. I agree with the analysis that most of the vertical stabilizer and rudder are there, not just part of it. You can see the white border below the colored stripes.

Air France pilots are making unofficial noises about not flying A330s or A340s until the pitots are changed as recommended by Airbus. Not enough information to attribute the accident to the pitot at this stage, and likely nothing will come of their musings.

There are other sources of data for the aircraft, including GPS and INS, but the pitots also feed a baro-inertial mixer for altitude and airspeed (inertials lag too much), and also provide density information to the engines. A Kalman filter manages and weighs INS, GPS and air data for navigation, but for functions like attitude, air density and climb/descent rate, air data (pitot inputs) is very heavily weighted.

When the central air data computer system is bad or unreliable, many bad things can happen. On most aircraft with a CADC system failure, it is safest to limit airspeed to a farily narrow band to prevent compressor stalls. Hard to do at heavy weight and high altitude over really nasty weather. This is a very complicated problem, and they really need the data recorders to figure out exactly what happened.

Taz
Terry Phillips

 

I noticed that the first time I saw it. There is a lot of torque being applied with no noticable effect.

 

Which leads to a theory offered by a friend who works for the FAA and is a combination of the lightning strike + vertical stab failure theories.

Airbus' fly-by-wire system limits rudder deflection above ~ 140kts. If that failed -- and it looks like it may have from the warnings -- it is possible that pilot inputs after the A/P disengaged overstressed the vertical stab with catastrophic consequences.

 

I can only say from an operational point, that our mechanics do not like the AB's because they are very confusing to work on. They say the Boeings are much more simplistic and the support is easier. As one of them told me, "Hey they are built by the French, that tells it all."

 

Well, it pretty much has the mass density of a styrofoam beer cooler -

 

Low density and large surface area

 

And that is exactly why I am so suspicious of the fracture of the lower trailing edge stab and rudder - how else could you get that sort of thing except by a massive control surface displacement, which initiates a breakaway of part of the rudder, then followed by a disastrous uncontrolled yaw which snaps off the whole veritcal stab?

I can imagine lots of parts breaking off in an uncontrolled stall/dive from falling off at altitude, but it is hard to imagine that exact damage to the rudder.

 

So, then, is it insulation material? Or is it really that light? Or maybe it's the shape. Obviously, steel floats if it's in the correct shape. But, when these things are damaged and compromised, I would think they're not airtight and water leaks in resulting in negative buoyancy.

CW

 

Again, if it's punctured/ruptured/compromised, wouldn't it flood and sink? Is it trapped air in the composite material itself? Carbon Fiber sinks, too. And, it's buoyant enough for 3 average sized men to be on it like a raft.

CW

 

The rudder is a watertight assembly, being glued together and made of a honeycomb material. I would imagine that the vertical stab. has airtight compartments also by virtue of being glued together. Spasso should know more about this than I. Spasso ?
Switches