Airasia Plane Missing?

[dagger]

Nothing unusual really. Getting to your flight planned altitude when you want it in this part of the world (and many others) can be a problem. Too many aircraft on the same routes. Weather deviations are generally approved but if other aircraft are already occupying that airspace and flight levels, you will need to review plan B.

I guess the question is whether a rapidly unfolding set of bad conditions left too little time for considering Plan B or C.

[HST]

Aircraft wreckage has been found. http://www.msn.com/en-ca/news/world/airasia-says-debris-is-missing-plane/ar-BBhlXhp?ocid=mailsignoutmd

Also, another incident today with AirAsia. http://www.news.com.au/world/asia/another-airasia-plane-is-involved-in-an-incident/story-fnh81fz8-1227170541671

[blues deville]

More details.

http://www.aeroinside.com/item/5119/indonesia-asia-a320-over-java-sea-on-dec-28th-2014-aircraft-went-missing-believed-to-have-impacted-waters-rnl

[Don Hudson]

Hi HST, re, "This (http://avherald.com/...=47d74074&opt=0) recent Airbus incident is unlikely related but worth considering."

The following is the slightly-earlier Airbus AD referenced in your post but with no link in the article. I think it may very well be related.

I know that what we think should have or should not have happened in the cockpit cannot explain this accident at this time, however reasonable speculation is worth engaging and I think your suggestion regarding the AD, actually the earlier one but they're related, is indeed "worth considering".

The captain's experience and time on the A320 does not suggest an intentional attempt to climb over a thunderstorm. None here who fly would ever think of such a thing and I think it is reasonable to assume that this captain would not either. That leaves us with an unintentional and sudden entry into a thunderstorm or a loss of control through other causes.

It will be interesting to find out if the radar was MEL'd. I doubt it but we don't know. Again, this captain's experience does not suggest that he would fly the route that day without radar. Also, other aircraft successfully travelled the route at various altitudes

The aircraft was found within six miles of the last known position, which fits well with the MAK study referenced earlier, (all sudden losses were within 12nm of the LKP and resulted from loss of control followed by a spiral dive, or in AF447's case, a stall in Alternate Law).

http://casa.gov.au/wcmswr/_assets/main/airworth/airwd/ADfiles/OVER/A320/2014-0266-E.pdf

Applicability: Airbus A318-111, A318-112, A318-121, A318-122, A319-111, A319-112, A319-113, A319-114, A319-115, A319-131, A319-132, A319-133, A320-211, A320-212, A320-214, A320-215, A320-216, A320-231, A320-232, A320-233, A321-111, A321-112, A321-131, A321-211, A321-212, A321-213, A321-231 and A321-232 aeroplanes, all manufacturer serial numbers

Reason:
An occurrence was reported where an Airbus A321 aeroplane encountered a blockage of two Angle Of Attack (AOA) probes during climb, leading to activation of the Alpha Protection (Alpha Prot) while the Mach number increased. The flight crew managed to regain full control and the flight landed uneventfully.

When Alpha Prot is activated 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.

To address this unsafe condition, Airbus have developed a specific Aircraft Flight Manual (AFM) procedure, which has been published in AFM Temporary Revision (TR) N° 502.

For the reasons described above, this AD requires amendment of the applicable AFM.

EASA AD No.: 2014-0266-E
TE.CAP.00111-004 © European Aviation Safety Agency. All rights reserved. 2/3
Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.

This is considered to be an interim action and further AD action may follow.
Effective Date:
11 December 2014

etc.

[HST]

I agree Don. The link was posted as a potential cause as accidents like this usually have other contributing factors. This AD might materialize as one of them. Thanks for engaging in the debate. With the wreckage located the cause will begin in earnest.

[mo32a]

The aircraft was found within six miles of the last known position, which fits well with the MAK study referenced earlier, (all sudden losses were within 12nm of the LKP and resulted from loss of control followed by a spiral dive, or in AF447's case, a stall in Alternate Law).

If the depiction of where the aircraft was found is correct, it was located behind it's LKP, is that common?

[Don Hudson]

Hi Rich;

The AD above and the one dealing with the A330/A340 are recent issues of similar ADs issued in 2012. These (for the A320 and A330/A340 series) were issued after a Lufthansa A321 experienced a serious event in November of 2014 attributed to the AoA probes.

Happy New Year to you! ;-)

[Don Hudson]

Hi mo32a, re "If the depiction of where the aircraft was found is correct, it was located behind it's LKP, is that common?"

If so, that's information, (new to me anyway); it could mean that the airplane was in a spiral dive or it more probably, (because one doesn't travel six miles horizontally in a spiral dive), could be that they had the airplane turned around and had proceeded eastward prior to whatever occurred to bring it down.

[John S.]

Or, one more thought: There's a current that needs to be considered.

[Don Hudson]

Hi John, Happy New Year!

I think drift due to current would affect anything floating on the surface but I don't think it would affect the aircraft itself after impact with the sea.

From what I read this morning, the actual wreckage site has not been found yet. News sources from Indonesia often have contradicting information. However given the depth of the sea and better weather, location should not take long once equipment capable of searching the sea bottom via sonar is available.

Bill Palmer, (author, "Understanding AF447") has offered some thoughts that are worth reading:

http://www.cnn.com/2014/12/31/opinion/palmer-airasia-air-france-disasters/

[blues deville]

Hi John, Happy New Year!

I think drift due to current would affect anything floating on the surface but I don't think it would affect the aircraft itself after impact with the sea.

From what I read this morning, the actual wreckage site has not been found yet. News sources from Indonesia often have contradicting information. However given the depth of the sea and better weather, location should not take long once equipment capable of searching the sea bottom via sonar is available.

Bill Palmer, (author, "Understanding AF447") has offered some thoughts that are worth reading:

http://www.cnn.com/2014/12/31/opinion/palmer-airasia-air-france-disasters/

Very interesting read. Thanks for the link.

[Kip Powick]

I would be amazed if the "dark shadow" that has been 'reported' would be the hull of the aircraft.

It is virtually impossible to see 50 meters, (over 150 feet) into the depths of the ocean and with the monsoon season in full swing, horizontal visibility would also be reduced to about 30 feet. We dove in that area and it was shortly after the monsoon season and visibility was very restricted.

What might have been "seen" is an underwater reef where the top of the reef may have been only 50 feet below the surface.

Be interesting to see where they actually find the bulk of the hull..

[Don Hudson]

I was wondering about visibility Kip, thanks for the experienced view! Yes, the mind can "see" all manner of things in ill-defined shapes and colors.

That said, is the dive a realistic one, or is it on the edge where mechanical recovery devices (like AF447's) will be required? I know one would have to consider depth, visibility, currents, reefs etc. I suspect they'll need assistance from Australia or the US.

I think the hull and wings are going to look much like the AF447 wreckage site; heavier items settling closest to the impact point, etc.

[Kip Powick]

A normal sport scuba diver can stay at 130 feet for 10 minutes with no decompression required,(on first dive only), although we always stop at 15 feet for 3 minutes to be on the safe side.(( I have broken the rule when trying to get a closer photo of a shark and did hit 160 feet or so but we had to do decompressions stops, (3), on the way up).

Over 130 feet professional salvage and recue divers will stay longer but must do decompression stops on the way back up. I think if the wreckage is between 100-150 feet it would not provide any difficulty for professional rescue divers, working in teams to bring the wreckage up without having to employ manned or unmanned submersibles.

I don't know the cut-off depth where those involved feel it would be safer, and perhaps faster, to employ submersibles.

The new underwater radios make the job much easier when the divers use wireless hard hats..

[Woody Pusher]

Don,

With reference to the MAK LOC and distance to surface from LKP data; I suspect something other than an immediate LOC situation has been involved in this particular accident.

S3.3708 E109.6911 LKP (ATC screen shot)

S3.9133 E110.5177 Debris (AV Herald)

123.15 T, 59.522 NM (110.234 Km)

Though pointless speculating!

Some ATC data - transcribed from a poor quality image.

[Moon The Loon]

I just can't believe we're having this discussion again, after the extensive review of AF447. On first view, this is a mirror image occurrence.

Unbelievable. Unforgiveable.

Unimaginable?

Unfortunately, no.

Repeatable?

More unfortunately: It's only just begun...

[Don Hudson]

Woody;

More mere speculation...!

With the difference between the ATC LKP and where the debris was found, (123T, 59nm), were you thinking mid-air break-up? The descent rate of just over 11,000fpm, if accurate certainly indicates LOC and a sufficiently-intact airplane to transmit a signal, (or is this calculated from a primary target?)

Moon...yes, incredible - there are only a few mechanisms by which this could have happened...

[Woody Pusher]

Don;

The ATC Target Data I posted earlier, appears to be from a PSR source, and the Geo.Vertical Rate of -11,516 ft/min would indicate "terminal velocity".

From the given position, the aircraft would appear to have been recovered and managed another 50+ nm to the ESE. Conjecture is that it was never recovered from a double flame-out and in the weather conditions at the surface an attempted ditching wasn't successful. There has been no indication of massive trauma to the bodies so-far recovered.

I assume that the Xpnder would normally get power from the battery back-up buss, so why was that off?

[Kip Powick]

A double flameout???

No " May-Day"...not even a "Pan-Pan"......I really find that a double flameout occurred and neither pilot got on the radio.........the CVR and FDR will be very interesting

[inchman]

A double flameout???

No " May-Day"...not even a "Pan-Pan"......I really find that a double flameout occurred and neither pilot got on the radio.........the CVR and FDR will be very interesting

They just about always are... interesting... to say the least, in these off-the-wall crashes.

[Seeker]

No " May-Day"...not even a "Pan-Pan"......I really find that a double flameout occurred and neither pilot got on the radio........

Aviate, Navigate, Communicate..........maybe they were too busy to make a radio call?

[mo32a]

^If that's the case, they failed horribly at job 1.

[Don Hudson]

mo32a...re "failed horribly"...bit early for that kind of judging isn't it?

We don't know what happened, and the qualifying "if" statement just makes it a tautology which by definition is a statement which proves / says nothing and so again we don't know if they "failed" or were overwhelmed by circumstance.

[Woody Pusher]

Of interest, and irrespective of Simon Hradecky of the Aviation Herald trashing the ADS-B data (as he calls it) that I presented earlier, the Indonesian Search and Recovery effort is focused in a narrow corridor from the two positions given to the now confirmed debris field.

My understanding is that the source of the two positions was a Primary Surveillance Radar which also was fitted with a Secondary Surveillance beam. Once the aircraft was identified via the aircraft transponder data, the Primary was able to continue tracking it once the ADS-B data was lost. The image below is a representation of possibly how the aircraft left the M635 airway and where it went. I'm not terrible happy with the 2316 position, but that is what the Indonesians have said it was.

Tim Vasquez of WeatherGraphics.com has used FlightRadar24.com data to determine the last ADS-B position, but I suspect that the data is as a result of FR24 substituting data when tracking is lost. If you look at the images posted by Tim, you'll note that highly convective tops are shown very close to where I believe that aircraft actually went:-

To date there has been no confirmed contact made with the ULB's attached to each of the DFDR and CVR, and previous experience is that often they don't work!

Surface winds and currents can be found at http://earth.nullschool.net/#2014/12/29/1200Z/ocean/surface/currents/orthographic=-251.39,-2.90,3000 The url to the left is for the currents at 2014/12/29/1200Z, and that portion of the url can be adjusted for the time you want. At present the wind at the surface is most likely having a predominate effect. Check for the correct url once you have opened the page in your browser.

[Don Hudson]

Hi Woody - I see something's being reported at 3.9241948672S, 110.5252477224E but someone has also noted that the Java Sea was a large theatre of operation during WWII, including the loss of a number of battleships...