Jump to content

Air France jet vanishes from radar


Frazer

Recommended Posts

There was a similar accident at the Peru coast, the maintenance people put tape on the data proves; this happened at night over the sea, the pilots got overspeed and stick shaker at the same time; they also got pull ap warnigs and several conflicting warnigs until they hit the sea...they were on a Boeing; now imagine the same scenario on an aircraft that is full flight by wire that don't have any type of mechanical feed back.

Link to comment
Share on other sites

  • Replies 226
  • Created
  • Last Reply

Top Posters In This Topic

From a few Aircraft disaster programs on Nat Geo, there's been a few rundown of similar situations like this:

- Left & right airspeed indicators wrong/not showing the same data.

- Left & right ADI not showing the same data.

- Overspeed warnings + Stall warnings.

- Stick shaker indicating stall.

- Autothrottle pulling back.

- Autopilot turning off.

 

So what system is telling the thruth - which one should you trust?

What do you do next?

 

It's probably easy to see in hinsight.

The mind is like a parachute. It only works when it's open | The important thing is not to stop questioning

Link to comment
Share on other sites

I guess nobody was paying attention to Altitude and Horizon/Pitch angle?

 

I mean engines at Idle with a 13+ degree pitch??? That is just counter intuitive...

 

The report as it is doesn't allow you to link these two facts in a causal manner. Anyway there is still discussion whether the pilots reacted appropriately, but then again I guess the 3.3 minutes they had (for as long as they remained conscious since it was a descent peeking at

-10,912 ft/min!) were essentially useless due to the abrupt high-altitude stall.

 

We could speculate that you can save a fighter aircraft from such a situation, but a big wide-body? Imagine the tremendous forces involved;

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

The throttle was only cut when already well into the descent. From the BEA interim report I gather:

 

- The A/P is disengaged and the PF starts to climb to about 10 degrees.

 

- Aircraft reaches a maximum of 38'000 ft. At this point, the power is set to TO/GA (Take-off and Go-Around => maximum power), but PF is still giving pull-up inputs and hence the aircraft goes into a stall.

 

- At 35'000 ft, the aircraft is having an AoA of 40 (!) and keeps falling.

 

- Throttle is cut for some reason, and the aircraft keeps falling

 

- Aircraft hits the water at 10'000 ft/min

 

It seems the crew got very confused by the faulty airspeed in combination with night+clouds (seems as if they started to doubt all their instruments). They had no outside reference and with stall warnings going on and off, things must have been chaotic. Naturally, in a stall situation, you would pitch down and then increase power, not climb...


Edited by X-man

 

2075291193_EDSig.png.650cd56f2b9a043311112721c4215a47.png

64th Aggressor Squadron
Discord: 64th Aggressor Squadron
TS: 135.181.115.54
Link to comment
Share on other sites

Why did they not pitch down and increase throttle? I don't understand how a stall can cause this to happen with a modern airliner..I'm not saying there was error...Just curious how this could happen...Even with fault readings you'd be aware you're stalling or in a dive...Are there not standard recovery procedures for this?

 

The throttle was only cut when already well into the descent. From the BEA interim report I gather:

 

- The A/P is disengaged and the PF starts to climb to about 10 degrees.

 

- Aircraft reaches a maximum of 38'000 ft. At this point, the power is set to TO/GA (Take-off and Go-Around => maximum power), but PF is still giving pull-up inputs and hence the aircraft goes into a stall.

 

- At 35'000 ft, the aircraft is having an AoA of 40 (!) and keeps falling.

 

- Throttle is cut for some reason, and the aircraft keeps falling

 

- Aircraft hits the water at 10'000 ft/min

 

It seems the crew got very confused by the faulty airspeed in combination with night+clouds (seems as if they started to doubt all their instruments). They had no outside reference and with stall warnings going on and off, things must have been chaotic. Naturally, in a stall situation, you would pitch down and then increase power, not climb...

Intel i7 6700k, Asus GTX1070, 16gb DDR4 @ 3200mhz, CH Fighterstick, CH Pro Throttle, CH Pro Rudder Pedals, Samsung Evo 850 SSD @ 500GB * 2, TrackIR 5 and 27" monitor running at 2560 * 1440, Windows 10.

Link to comment
Share on other sites

Why did they not pitch down and increase throttle? I don't understand how a stall can cause this to happen with a modern airliner..I'm not saying there was error...Just curious how this could happen...Even with fault readings you'd be aware you're stalling or in a dive...Are there not standard recovery procedures for this?

 

Again, at that height there is not much air that you can use to produce lift. The forward vector is extremely important to stay aloft. Minor errors in forward speed can cause catastrophic results. If at that moment your speed indication is erroneous, you have very little options.

 

You also have no visual clues whatever at that altitude. Gravity is not your friend, and an A-330 is a heavy aircraft. You must take into acount that it fell from the sky like a brick. You can totally not compare it to a stall at 6000 ft in Lockon in a fighter-sized aircraft.

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

Again, at that height there is not much air that you can use to produce lift. The forward vector is extremely important to stay aloft. Minor errors in forward speed can cause catastrophic results. If at that moment your speed indication is erroneous, you have very little options.

 

You also have no visual clues whatever at that altitude. Gravity is not your friend, and an A-330 is a heavy aircraft. You must take into acount that it fell from the sky like a brick. You can totally not compare it to a stall at 6000 ft in Lockon in a fighter-sized aircraft.

 

Very frightening stuff. I really feel for those poor poor people on board. It must have been horrific. It seems a lesson has been learned and the failing instrument has been replaced, but what a terrible way to learn a lesson.

Intel i7 6700k, Asus GTX1070, 16gb DDR4 @ 3200mhz, CH Fighterstick, CH Pro Throttle, CH Pro Rudder Pedals, Samsung Evo 850 SSD @ 500GB * 2, TrackIR 5 and 27" monitor running at 2560 * 1440, Windows 10.

Link to comment
Share on other sites

Very frightening stuff. I really feel for those poor poor people on board. It must have been horrific. It seems a lesson has been learned and the failing instrument has been replaced, but what a terrible way to learn a lesson.

 

It's possible the crew did not fully comprehend how much trouble they were in; hopefully it was a similar case for the souls in the cabin.

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

A slight derail - but since this flight hasn't been the only one going down due to sensor-problems:

- I don't understand why the aircraft industry hasn't been more concerned over the fact that these sensors, monitoring and automation is now critical to stay airborne.

 

The combine factors of:

a) Automation of a lot of the standard procedures & operations.

b) Putting either a computer or a human to monitor it (Airbus vs Boeing) - making decitions based on flawed sensors.

c) Not having implemented sufficient faulty sensor detection

d) Not sufficiently training pilots to detect faulty sensors together with safe standards to stay airborne even with critical sensors going offline.

 

I hope the industry learns - and quickly.

 

In todays times it has always been a race between the quality factor and the money factor. I had been working in a petrochemical plant(biggest organization in my country) for 3 years and what I had seen there only tell the story of saving money to all possible extent by the manufacturers. Remember the oil rig of BP in gulf of mexico.. Every manufacture at all levels is trying to reduce manufacturing costs either to increase profit or stay in competition or both. International quality and safety rules are bent as fas as possible, testing of the equipments are done at optimum conditions and not worst possible conditions. There are so many co-contractors working of Airbus, so if we not consider Airbus to be the culprit there are can be one or more of their contractor supplying products which are more economic than safe(quality). For what I know about the hardcore manufacturing industries everybody are still running because either have good people working for them or they are just lucky.

Link to comment
Share on other sites

Read through the last few pages in this thread and one thing that has not been mentioned much is the weather they were flying through at the time of the incident.

 

I have flown in this area of the Atlantic for 10 years and they were flying through an area known as the ITCZ, Inter Tropical Convergenge Zone. Its a area of massive conventivity giving rise to some of the largest and highest Thunderstorms you will find anywhere. Also these TSs aren't necessarily solitary but quite often form a line Squall (I have flown 200 miles off track on one memorable occasion).

 

So, back to the incident. They have pitot source information giving them erroneous speed instrument indications. The aircraft has overspeed/stall/overbank/overpitch protection systems all of which are now receiving incorrect information and therefore the plethora of failure messages & warnings (over 20 in total I believe). Their EICAM must have lit up like a christmas tree. Their autopilot system failed, their fly-by-wire system was in alternate law (which still has some of the aforementioned protection systems which kick in even when the autopilot is disengaged) and they are still avoiding convective cloud/TSs. What isn't known yet is whether their ADIRU (provides attitude info) failed or was giving erronious information. If this is so & at night with no discernable horizon they really were in a tight spot so to speak.

 

If you just lose your airspeed and nothing else you can fly pitch & power settings (there is even a non-normal checklist for it in the Boeing) but if you are fighting protection systems & there is more failures on top then any crew are going to struggle.

 

We can draw conclusions to our hearts content but until the accident report is published maybe I have given the armchair pilots a little insight into the fact that it isn't as straight forward as "they were stalling so why did he have the nose up".

 

"Co-pilot PF said "I don't have any more indications", and the co-pilot PNF said "we have no valid indications"."

 

I don't even know wtf that means. They have two copilots? Since when?

They had 3 pilots on board, 1 Captain & two F.O.'s. On long flights which are outside the normal crew duty hours you carry an extra (sometimes 2) pilot which allows each pilot about 3-4 hrs rest/sleep which extends their available crew duty hours. The Captain arriving in the flight deck having just woken would have been in a poor state & again without the CVR 'report we're not sure he even made it into his seat which was occupied by the relief F.O.

i7-7700K : 16Gb DDR4 2800 Mhz : Asus Mobo : 2TB HDD : Intel 520 SSD 240gb : RTX 2080ti: Win10 64pro : Dx10 : TrackiR4 : TM Warthog : ASUS ROG SWIFT PG348Q

Link to comment
Share on other sites

the weather is a curiousity...

 

is it possible that exceptionally strong winds/ long gusts could have caused havoc with the flight surfaces and indicators, along with systems failure?

 

ie an exceptionally strong tail wind fooling the system into thinking the plane was flying slower than it was, as well when pitched up (probably to try and get up over the storm?) a strong headwind fooled the system into thinking the plane was faster than it was?

City Hall is easier to fight, than a boys' club - an observation :P

"Resort is had to ridicule only when reason is against us." - Jefferson

"Give a group of potheads a bunch of weed and nothing to smoke out of, and they'll quickly turn into engineers... its simply amazing."

EVGA X99 FTW, EVGA GTX980Ti FTW, i7 5930K, 16Gb Corsair Dominator 2666Hz, Windows 7 Ultimate 64Bit, Intel 520 SSD x 2, Samsung PX2370 monitor and all the other toys

-

"I am a leaf on the wind, watch how I soar"

Link to comment
Share on other sites

The problem with Thunderstorms & highly convective cloud is rapid updraughts & downdraughts (turbulence) combined with heavy rain, lightening & possibly Hail & at the upper levels heavy icing. Changes in lateral wind direction & speed are less significant.

 

Tailwinds do not fool aircraft into thinking they are flying slower than they are unless of course you have blocked pitot probes

 

The only speed indication the aircraft has then comes from its groundspeed fed from the INS/GPS.

i7-7700K : 16Gb DDR4 2800 Mhz : Asus Mobo : 2TB HDD : Intel 520 SSD 240gb : RTX 2080ti: Win10 64pro : Dx10 : TrackiR4 : TM Warthog : ASUS ROG SWIFT PG348Q

Link to comment
Share on other sites

If you just lose your airspeed and nothing else you can fly pitch & power settings (there is even a non-normal checklist for it in the Boeing) but if you are fighting protection systems & there is more failures on top then any crew are going to struggle.

 

We can draw conclusions to our hearts content but until the accident report is published maybe I have given the armchair pilots a little insight into the fact that it isn't as straight forward as "they were stalling so why did he have the nose up".

 

 

First of all they were indeed trying to evade a turbulence region;

Second, what is lacking in the English translation of the BEA report and what I read in the French texts is that while the aircraft was descending post stall, the aircraft had heavy erratic movement which the pilots were fighting. So indeed, it is a little simplistic to state "why didn't they push nose down".

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

Here on this video you can see the type of automatization the airbus uses.

You can see that the computer won't let you stall the airplane; where the pilots trained to fly the jet full manual; without the help of the computer?

was the ADI working? if not I figure they suffer the same type of confusion of the Aeroperu 603

 

Link to comment
Share on other sites

  • 1 month later...

[sIGPIC][/sIGPIC]

Link to comment
Share on other sites

 

How do you know stalled the airplane if you can't rely on your instruments?

Link to comment
Share on other sites

  • 4 months later...

New article with long excerpts from the cockpit voice recorder: What Really Happened Aboard Air France 447.

 

 

02:13:40 (Robert) Remonte... remonte... remonte... remonte...

Climb... climb... climb... climb...

 

02:13:40 (Bonin) Mais je suis à fond à cabrer depuis tout à l'heure!

But I've had the stick back the whole time!

 

At last, Bonin tells the others the crucial fact whose import he has so grievously failed to understand himself.

 

02:13:42 (Captain) Non, non, non... Ne remonte pas... non, non.

No, no, no... Don't climb... no, no.

 

02:13:43 (Robert) Alors descends... Alors, donne-moi les commandes... À moi les commandes!

Descend, then... Give me the controls... Give me the controls!

  • Like 1
Link to comment
Share on other sites

Those circuits, pretty much like the rest of the aircraft, are shielded.

 

The investigation is done, and it wasn't lightning.

 

speculation on my part..

airbus is flyby wire, so lightning may have casued the circuits to go awol, any inputs from pilot may have went unregistered.. causing a steep dive beyond recovery.

[sIGPIC][/sIGPIC]

Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

Link to comment
Share on other sites

We now understand that, indeed, AF447 passed into clouds associated with a large system of thunderstorms, its speed sensors became iced over, and the autopilot disengaged. In the ensuing confusion, the pilots lost control of the airplane because they reacted incorrectly to the loss of instrumentation and then seemed unable to comprehend the nature of the problems they had caused. Neither weather nor malfunction doomed AF447, nor a complex chain of error, but a simple but persistent mistake on the part of one of the pilots.

 

..................................

 

 

ic the possible mistake they turned on anti ice to late , flying at high alts and speed through cloud layers. imo the aircraft iced up and the sensors.

..........................................

02:06:50 (Bonin) Va pour les anti-ice. C'est toujours ça de pris.

Let's go for the anti-icing system. It's better than nothing.

 

Because they are flying through clouds, the pilots turn on the anti-icing system to try to keep ice off the flight surfaces; ice reduces the plane's aerodynamic efficiency, weighs it down, and in extreme cases, can cause it to crash.

 

 

....................


Edited by diveplane
Link to comment
Share on other sites

I travel a lot and often fly. It scares me to death to even think that pilots flying this miracles of technologies are often not trained, thus not qualified to fly them. These two co-pilots were not trained to recover from stall!! Incredible, scary, unbelievable!

Thermaltake Kandalf LCS | Gigabyte GA-X58A-UD3R | Etasis ET750 (850W Max) | i7-920 OC to 4.0 GHz | Gigabyte HD5850 | OCZ Gold 6GB DDR3 2000 | 2 X 30GB OCZ Vertex SSD in RAID 0 | ASUS VW266H 25.5" | LG Blue Ray 10X burner | TIR 5 | Saitek X-52 Pro | Logitech G930 | Saitek Pro flight rudder pedals | Windows 7 Home Premium 64 bit

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...