Air Asia Indonesia Lost Contact from Surabaya to Singapore

[alph2z]

From Emergency Airworthiness Directive (AD) 2014-25-52

... due to blocked AOA probes, the flight control laws
order a continuous nose down pitch rate that, in a worst case scenario, cannot
be stopped with backward sidestick inputs, even in the full backward position. If
the Mach number increases during a nose down order, the AOA value of the
Alpha Prot will continue to decrease. As a result, the flight control laws will
continue to order a nose down pitch rate, even if the speed is above minimum
selectable speed, known as VLS.
This condition, if not corrected, could result in loss of control of the aeroplane....


AD – AFM Procedure
• If the Alpha Prot strip (black and amber) completely and permanently hides the VLS strip (amber) in a stabilized wings-level flight path (without an increase in the load factor):

Keep on one ADR.
Turn off two ADRs.

(emphasis mine)

Gesus: this reads a bit like Space Odyssey 2001 where Dave is deactivating HAL.

[training wheels]

...and YES, communicating is last thing and quite useless if you are falling from the sky...

That goes without saying for anyone who is a professional pilot. Those who question it, really shouldn't be here ...

[mixture]

So to sum up-
There IS sufficient satellite bandwidth to send DFDR/CVR data but probably as a short burst when the aircraft thinks it has a problem rather than a continuous download.

So to sum up .... I'm right. There IS insufficient bandwidth.

[glendalegoon]

eabandit

would you rather spend 10 million on tracking or training for pilots to be safer?

you don't have all the money in the world to spend.

And quite frankly , every passenger has a choice on which airline to fly and votes with his pocketbook.

Not that a reservation agent will know, but simply find out. Does your airline, if the route is over significant , non radar covered , bodies of water have tracking?

IF NO, don't fly on them.



I know how I would run an airline and how to allocate resources. And looking back and saying: gee, if we had put gadgets on all the planes we wouldn't have to send out the 7th fleet to find things and think abouthow much money that would save.

It doesn't work that way.

[framer]

But - does pressing the Tx button involve that much distraction from the acknowledged essentials? Perhaps it does?

Like others have said, it is obvious when people posting here are not professional pilots and it creates a situation where there is debate about things ( such as above) that there is no debate about between the pro's. It is a waste of space and moves the conversation further away from where it should be in a professional pilots forum.
If you are using 99% of your brain to try to make sense of what erroneous instrumentation is telling you while at the same time being affected by g forces, now is not the time to allocate 10% of your brain space to making a radio call.

[Brenoch]

Apparently I'll have to rephrase that. What's the point in reiterating "aviate, navigate, communicate" on a forum presumably used by pro's? Most likely it all went pear shaped at aviate for some reason and I'm fairly certain they knew what was next, only they never got to that step in this marvel that is aviation.

[DCrefugee]

If you are using 99% of your brain to try to make sense of what erroneous instrumentation is telling you while at the same time being affected by g forces, now is not the time to allocate 10% of your brain space to making a radio call.

+1. Besides, you're still planning to fix whatever the problem is, so issuing a Mayday call is admitting defeat. And you may not know enough about the problem to verbalize it in the first place. This whole conversation is rather silly...

[Hedge36]

Originally Posted by framer

Like others have said, it is obvious when people posting here are not professional pilots and it creates a situation where there is debate about things ( such as above) that there is no debate about between the pro's. It is a waste of space and moves the conversation further away from where it should be in a professional pilots forum.
If you are using 99% of your brain to try to make sense of what erroneous instrumentation is telling you while at the same time being affected by g forces, now is not the time to allocate 10% of your brain space to making a radio call.

I've been addressing this very topic repeatedly today with my non-aviator friends. They simply cannot comprehend the difference between making a radio call containing dubious information - yielding zero result - and a call to 911/999 asking for assistance.

News flash, lurkers: "Ground, 8501, we've departed" will get you

no

help

at all.

[truckflyer]

"due to blocked AOA probes, the flight control laws " From Emergency Airworthiness Directive (AD) 2014-25-52

If this situation is not understood fairly fast, there will be not long time until you have lost full control.

This will depend on the training department, sending out a directive does not necessary mean that this is understood, how the aircraft will behave.

Of course there will be a combination of things colluding at similar time that will confuse the pilots.

Bad weather in combination with this, and the Swiss cheese model can be lined up step by step!

I experienced this scenario in the Sim without being aware of this, and it did not take long time before you sat there fat, dumb and happy, without a clue of what to do!

Because you get conflicting messages and you can not control the aircraft! The time it takes for this to develop is not very long, and before you know it you might be in an unrecoverable state!

[peekay4]

That climb request to FL380 "to avoid weather" has been puzzling me.

(begin speculation)

Now I think the pilots were not overly concerned with the weather, before flying into a developing cell.

Consider, at the time, there were up to seven other planes nearby, including several flying just ahead and just behind QZ8501 on the same airway. According to media, none of the other pilots reported flying through strong turbulence or any other hazardous conditions.

It seems to me that QZ8501 was a routine flight. There was some weather ahead so they requested deviation to the left, like they've done hundreds of times before. From the radar picture you can see Emirates 409 had done the same just ahead. In fact, QZ8501 was joining the track UAE409 had left a few minutes before.

Then they requested climb to FL380 not due to "weather" per se, but because it was routine at this stage of the flight to climb higher (being lighter with less fuel). I've reviewed several other A320 flights on this route and it's not unusual to see flights go to FL360 or FL380 near this spot.

The routine aspect of this climb is what makes me think the crew was not overly concerned about the weather or the situation they were in. If they were seriously concerned, they would have deviated further first, not climb up at that point.

(I can see pilots climbing to better assess what's ahead, and maybe for a smoother ride, but I highly doubt a very experienced Captain from the tropics would try to out-climb a cumulonimbus.)

Yet the radar picture shows QZ8501 at FL363 and climbing (*). Perhaps control was already lost at this point. By deviating left, they inadvertently flew into a newly developing CB with very powerful updrafts. The plane is violently pushed up, nose very high, and quickly rolled to one side; groundspeed rapidly drops.

The pilots tried to recover from the unusual attitude and were not able to do so.

The plane did not "break up in flight", but flight control was lost. Perhaps the rudder or other control surfaces sheared. As the plane was plunging to the ground, below FL290, the ADS-B signal was lost due to line-of-sight distance from the nearest ground station at Pangkalan Bun.

The aircraft was largely intact when it impacted the ocean, perhaps steeply nose-down, creating few debris. The pilots tried to save the airplane all the way down.

(*) also note that ATC FLs are not actually physical altitudes but derived from Mode C pressure transmissions, which may be erroneous.

(end speculation)

[touch1337]

Originally Posted by peekay4

That climb request to FL380 "to avoid weather" has been puzzling me.

This seems to be media speculation rather than fact. The official statement of events says that they dont know why he requested to climb:

According to AirNav, the pilot then asked to take the plane from 32,000ft (9,800m) to 38,000ft but did not explain why he wanted to do so.

source

[Lost in Saigon]

From what I have been reading, they were initially maintaining 470 knots at FL320 and requested a course deviation and climb to FL380. They never responded to the clearance to climb to FL340 and they were probably out of control as they climbed through FL363 with a groundspeed of only 353 knots. (approx 333 knots TAS) (approx 180 knots IAS)

What was the time of the AirNav Indonesia Radar screen shot showing them climbing through FL363? I assume it was at approx 06:14-06:16 local.

Details from AirNav Indonesia (http://www.airnavindonesia.co.id):

06:12

- QZ8501 requests left deviation from airway. Deviation approved.
- Pilot then requests climb from FL320 to FL380
- ATC asks pilot to standby, due to nearby traffic and to coordinate with next sector (Singapore)

06:14

- ATC calls QZ8501 to approve partial climb to FL340
- No response received after 2 or 3 further attempts to contact
- ATC requests help from nearby aircraft to contact QZ8501

06:16

- ATC still cannot reach QZ8501
- Aircraft still observed on radar screen

06:17

- Radar contact lost
- Last reported altitude: FL290

The Aviation Herald Crash: Indonesia Asia A320 over Java Sea on Dec 28th 2014, aircraft went missing believed to have impacted waters

A radar screenshot leaked from AirNav Indonesia shows the aircraft had turned left off the airway and was climbing through FL363, the speed over ground had decayed from 470 knots at FL320 to 353 knots however.

On Dec 29th 2014 Indonesia's Ministry of Transport reported the aircraft took off from Surabaya at 05:36L (Dec 27th 22:36Z), at 06:12L contacted Jakarta Center enroute at FL320, Jakarta Center identified the aircraft on radar. The crew requested to climb to FL380 and requested to deviate to the left of M-635 around cloud. The aircraft seemingly was on the radar screen at 06:16L, at 06:17L only the ADS-B signal remained, contact with ATC was lost, at 06:18L the target disappeared from the radar screen. At 07:08L INCERFA was invoked by ATC, at 07:28L ATC declared ALERTFA and at 07:55L DETRESFA was declared by ATC. According to standard operating procedures AirNav Indonesia opened a crisis center under the lead of the director of Civil Aviation at the Tower of Jakarta Airport. All crew with the exception of the first officer (French citizen) were Indonesians. In addition to the 6 crew there were 155 passengers on board of the aircraft.

On Dec 29th 2014 AirNav Indonesia reported that the captain of the flight requested to climb to FL380. AirNav Indonesia coordinated with Singapore, which took not more than two, maybe three minutes. Due to other traffic the aircraft could not get cleared to FL380 instantly and was cleared to FL340 at first. When the aircraft was radioed with the clearance to climb to FL340 at 06:14L, there was no response anymore. At that time the aircraft was still visible on the radar screen, the controller asked other aircraft around QZ-8501 to relay, but neither aircraft received a response from QZ-8501. There were seven aircraft passing through the area at that time at flight levels between 290 and 380, neither of them encountered any difficulties. The radar target of QZ-8501 disappeared from radar screen at 06:18L.

AirNav Indonesia Radar screen shot:



Chart showing 20 Knot tailwind

[727forever]

Some pilots have been able to call ATC when their aircraft was doomed, the PSA 727 crash comes to mind as a good example. This was after the crew knew they had lost control of the aircraft and they had time to let the tower know. Every situation is different and every crew member is different, if you have time to let ATC know whats happening that's a good thing, but only after you have addressed the priorities as other members on this board have mentioned.

09:01:55 Captain (to Lindbergh tower) Tower, we're going down, this is PSA
09:01:57 Lindbergh tower OK, we'll call the equipment for you
09:01:58 Unknown Whoo!
09:01:58 ((Sound of stall warning))
09:01:59 Unknown Bob!
09:01:59 Captain (to Lindbergh tower) This is it, baby!

[WTech]

What about the FDR pinger/locator?

Has anyone got any updates/details about whether there are signals from the FDR pinger locator - seems to be ignored in this thread ?!

[The FUB]

Does this A320 variety suffer at all from Ice Crystal Icing? Any operators have first or second hand experience of this on a A320 series?

[training wheels]

Originally Posted by peekay4

That climb request to FL380 "to avoid weather" has been puzzling me.

(begin speculation)By deviating left, they inadvertently flew into a newly developing CB with very powerful updrafts. The plane is violently pushed up, nose very high, and quickly rolled to one side; groundspeed rapidly drops.


(end speculation)

I don't fly the bus so I may have the terminology wrong here, but in normal law, wouldn't the high angle of attack and high angle of bank protection prevent this from happening?

[Mad (Flt) Scientist]

Originally Posted by The FUB

Does this A320 variety suffer at all from Ice Crystal Icing? Any operators have first or second hand experience of this on a A320 series?

There's an EASA proposed AD (PAD 14-139 Date: 09 September 2014) which appears to potentially apply to all A320 series, but the critical factor appears to be which variety of probe is fitted. (The PAD does not specify what the replacement probe is to be, just what is to be removed and is no longer allowed; I seem to recall that at one time there was a suggestion that this was a "Thales/Sextant problem" and some operators were intentionally introducing "mixed" probe configurations (Goodrich mixed with Thales) as a kind of "insurance" again this being a design flaw, but I think there have been Goodrich incidents since, so that theory may have been discredited.

But perhaps a more important point is that practically all pitot probes are vulnerable to the ice crystal phenomenom; until very recently, nothing in the certification of probe addressed it at all, so any robustness one design might have had was as much luck as by design.

[Mad (Flt) Scientist]

Originally Posted by training wheels

I don't fly the bus so I may have the terminology wrong here, but in normal law, wouldn't the high angle of attack and high angle of bank protection prevent this from happening?

Simplistically, not necessarily.

The protections are pretty much fool proof against a pilot induced high aoa/low energy state being achieved - it just won't let you command the plane into trouble (again, simplistic) - but subject the aircraft to a massive external disturbance, and there's not a lot the FBW can do if the disturbance is too big. If full nose down elevator isn't enough to prevent an externally induced pitch up, the FBW is along for the ride, just like a crew of a conventionally controlled plane.

This is where we get the difference between "An airbus cannot be stalled" - which is kind of true, as it implies that this is a "commanded stall", and thus the FBW can simply prevent the pilot from causing the stall - and "An airbus cannot stall" which implies magic aerodynamics that work at 90 degrees AOA, and which neither Toulouse nor anyone else has the ability to create.

[etudiant]

Quote:
Has anyone got any updates/details about whether there are signals from the FDR pinger locator - seems to be ignored in this thread ?!




Probably the plan is to wait for the weather to clear and hopefully have some debris spotted before the acoustic search is begun. At least the search should be fairly flexible because there is no need to stream several miles of cable just to get the fish down close to the bottom.
Still, finding the pinger in a shallow and heavily trafficked strait will not be easy.

[mickjoebill]

I am in favour of reducing the stress and trauma on the thousands of relatives of missing passengers, who themselves are victims.
Apparently many hold out hope, even now, that their loved ones could be alive or injured.


A dozen $400 plbs and a few more eperbs distributed throughout the cabin would if nothing help those left behind come to a more speedy realisation of the prospects of survival of their loved ones.

The relience on one or two ruggedised expensive locator beacons to locate wreckage in water quickly has failed us in this regard.

So the likelyhood of lets say, one in twelve non ruggedised water activated epirbs suviving the chaotic nature of a crash and floating to the surface should now be considered.

A proactive carrier could provide a belt worn plb to cabin crew and stuff one in the survival pouch of every life raft.

A plb holstered above every exit door with instructions on its use in the seat back saftey card would also be a step forward.

In the eyes of the travelling public the aviation industry is making an ass of itself.