Air Asia Indonesia Lost Contact from Surabaya to Singapore

[Propduffer]

Here's a summary of all the information I've been able to glean about search locations:


Asia Air LRP ----> from a graphic released by the Indonesians
52.9 miles from RAFIS ----> Training wheels post # 1421
TAIL ----> Suggested by MGS Ship Geo Survey
tail ----> Suggested by Jeff Wise
Blue suitcase ----> From a picture of Debris released by the Indonesians
FR24 LRP 23:12:37 ----> ADS-B Last reported position
sunken boat ----> a finding by sidescan sonar

[EEngr]

refer constantly to "the black box" when (so I thought) everybody knows that there are two.

New digital units are often combined units. Both FDR and CVR functions in one 'box'.

Flight recorder - Wikipedia, the free encyclopedia

[onetrack]

Santoso Sayogo, an investigator at the Indonesian National Transportation Safety Committee has stated to the media that he has received a report from the field, that their SAR people are now picking up pings from the flight data recorder - and that the pings are some distance from the location of the tail, thus indicating the FDR became detached during the crash.

[_Phoenix]

Black box not in the tail

As per video below, it seems that the black box was separated from tail "a few hundred meters downstream"
BBC News - AirAsia QZ8501: 'Divers in water trying to raise plane'

[p.j.m]

Originally Posted by onetrack

Santoso Sayogo, an investigator at the Indonesian National Transportation Safety Committee has stated to the media that he has received a report from the field, that their SAR people are now picking up pings from the flight data recorder - and that the pings are some distance from the location of the tail, thus indicating the FDR became detached during the crash.

I wonder exactly what "detected 300 metres from" means. but anyway... good news if they have located them!

Jakarta: "Ping" signals from the black box of downed AirAsia flight QZ8501 have been detected 300 metres from the aircraft's sunken tail section, Indonesian army commander Moeldoko has confirmed.


General Moeldoko said the ping was picked up by Indonesian ship Jadayat well away from the tail, which is the current focus of the search and recovery effort.

AirAsia crash: 'ping' signals from black box detected

[PastTense]

This Air Asia crash, if it's similar to the Air New Zealand crash, was in bad weather making diagnosis and recovery even harder, so even with the best pilots, they may not have had a chance to recover.

Coagie:
While the weather situation was much worse for the Air Asia crash than the Air New Zealand crash, the altitude situation was much worse for the Air New Zealand crash: the Air New Zealand pilot did the acceptance tests at low altitude so there was very little time and distance to attempt recovery--while the Air Asia was at high altitude and had a significant amount of time and distance to attempt recovery.

The search and rescue team, on Friday morning, found the bodies of three more victims of the AirAsia QZ8501 flight, Commander of Iskandar Military Airport in Pangkalan Bun Jhonson H. Simatupang stated here on Friday.

"In total, we have found 46 bodies out of the 162 passengers of the plane," stated Jhonson.

http://www.antaranews.com/en/news/97...-victims-found

[Leightman 957]

Originally Post by onetrack
Santoso Sayogo.....he has received a report.....that the pings are some distance from the location of the tail, thus indicating the FDR became detached during the crash.

Interesting to know how distant. AF447 (below) had ~10,000' for currents to nudge debris yet the FDR module was within maybe 150' of the APU, THS, and CVR (though farther from the FDR chassis). Air Aisa's search depth is only ~100'. The FDR would not have flowed with current, though the tail might have depending on what we find it looks like now. However the distance between FDR and tail, and the heading between, calculated together with the current should be telling about what part touched down first, and what forward speed might have caused the distance.

AF447: Map of the debris field - Flight International

Don't misconstrue. I use AF447 ONLY because despite the huge difference in circumstances between the two, debris field maps don't grow on trees, especially accidents that generate huge interest and lots of valuable images for a hungry media, so there aren't a lot to choose from. And comparisons between the two can be as instructive for their dissimilarities as their similarities.

[Capn Bloggs]

Originally Posted by Airscotia

If an updraft was taking him through FL360 with dropping airspeed

An updraft will not in itself reduce airspeed. Updrafts add energy, not reduce it. The first reaction by the autopilot (or PF) would be to try to maintain altitude by putting forward pressure on the stick. This will in effect increase the speed because of the updraft wind vector (and no, I do not subscribe to the previously mentioned theory that the wing will get hit before the tail, so the nose will rise markedly; it all happens too fast for that). Next, the power will come off (ATS) the crew may pull the SB out to keep the speed under control or, as I understand in an Airbus, if an overspeed is going to occur, the AP will raise the nose. The only real problem with convective activity (if the aeroplane doesn't fall apart flying into the updraft in the first place) is the subsequent possible downdraft encounter out the other side. Perhaps with the nose climbing (Airbus) and speed now reducing (no updraft, or potentially a downdraft)... it should still be controllable with full forward stick and full power (which would already be set by the ATS as the speed is below target).

I do not buy the claimed 9000ft/min ROC and massive speed reduction was caused only by an updraft. And that would assume they were actually in a cell. Updrafts are essentially overshoot shear scenarios, and you don't stall in those scenarios.

[Propduffer]

Although we don't know exactly what it was based on - because we were never told what radar had reported this, but in the first few days all the media was reporting that they had been told that the GS for QZ8501 was very low.

Now that we have the ADS-B information we can be sure this low groundspeed couldn't have come from secondary radar so it had to have come from a military primary radar. Or it might have been bogus information, but it has never been retracted afik.


Edit: After a bit of research I've come to the conclusion that the entire basis for the low speed assumptions for QZ8501 have been based on that radar plot which was released on day one of this event and had the numbers 363 which was taken to be the altitude and the number 353 which was taken to be the speed (IAS at FL 36.0).

That's not very solid evidence, that "radar plot" may have been composed for a news release quickly - it may have been mostly eye candy.

[sopwithnz]

small correction, but important ...

It was not an Air New Zealand captain or pilot in the seat for the Perpignan crash. He was a German pilot for the safety checks to return the plane to Air New Zealand. Very sad circumstance ... and nothing the crew could do to save themselves.

https://www.youtube.com/watch?v=jJrK-1qr59M

[Derfred]

I do not buy the claimed 9000ft/min ROC and massive speed reduction was caused only by an updraft.

Thank you Bloggs.

This whole "updraft" discussion is completely baseless on the known information.

[autoflight]

tcas

In ordinary circumstances, TCAS can be very useful for awareness of other aircraft.

If pilots have their hands full controlling aircraft in severe conditions or possibly eyeball bounce, things become more difficult. I spent a lot of effort avoiding this stuff. Experienced plus and minus 3000 ft in turbulence and iceing with seriously impaired vision in an embedded CB in my early days. There was no such thing as TCAS, but if there had been, it would have been useless, due poor vision.

[bille1319]

Tidal currents

The tidal streams seem to have quite a range in the search area, something like a 2-3m range. We're just past Springs or full moon so they should be easing now with neaps on the 13th, the best conditions for diving there.

[training wheels]

Originally Posted by Propduffer

That's not very solid evidence, that "radar plot" may have been composed for a news release quickly - it may have been mostly eye candy.

I can assure you catergorically that radar plot I posted on page 1 came from a well respected senior ATC controller at Jakarta whom I know personally.

[chefrp]

Propduffer

It seems to me that any pilot who has flown gliders in the past would just smile ear to ear (and maybe even throw the plane into a sharp turn so as to not lose the updraft)

Not sure anyone would be "smiling ear to ear" faced with the still unknown situation QZ8501 was in...

Furthermore I don't believe the Captain lacked in flying ability...I feel his experience flying fighter jets would attest to this...

Blind speculation is just that at this point... for all we know the Captain went to the toilet and all hell broke loose...it has happened before...

[VR-HFX]

When they find the nose section, it could well look like this:

Oh, Hail! | Aero-News Network

Which may also explain the "no comms" due possibly to shredded antennae.

It may also explain the low GS due possibly to flame outs.

Anyone who has a lot of experience in SE Asia has noticed a large increase in "newbies" who believe the glossy brochures and management cost mantra that modern a/c can weather any storm.

For those who have been in one and lived to tell the tale, they never, ever do it a second time.

If the CVR has been located, we shall all know soon enough.

RIP to all those innocent souls

[airsound]

New digital units are often combined units. Both FDR and CVR functions in one 'box'.

I stand to be corrected, EEngr, but I think you're referring to the ‘enhanced airborne flight recorder’ (EAFR). As I noted in the 787 thread (#2161, 3 Dec), according to the NTSB report on the Boston battery fire, the 787 is the only aircraft so far that

uses the EAFR to record CVR, FDR, and other data.

As it happens, the 787 EAFR seems to be problematic, but that's for another thread.

The upshot is that I'm assuming we're talking separate FDR and CVR in PK-AXC.

[mm43]

This appears to be where the search is currently at:-

[Flagon]

Any chance you could authenticate those height, heading etc readings or do we just dismiss them?

[TyroPicard]

sopwithnz

and nothing the crew could do to save themselves.

Not true, but this is not the place to discuss it.