Airasia Plane Missing?

[GDR]

Good post as usual Don, (except for the ones where we don't agree ).

Mistakes are made by everyone but a lot depends on how we react to those mistakes. Apparently here again, as in cases such as AF and Colgon, the crew has no idea how to recover a stalled airplane. That is one of the first things we learned in basic training. It seems that there are a lot of people out there with no grasp whatsoever of basic airmanship.

[Don Hudson]

Apparently washed up 550km east of the site, https://www.google.com/maps/place/Sembilan+Island,+Baru+City,+South+Kalimantan,+Indonesia/@-2.7647096,113.529495,7z/data=!4m2!3m1!1s0x2de8019f3cbd1047:0xba140c6d211c1388

[Don Hudson]

Hi Greg...can you help? I used the expression "put out their eyes" to express the idea that computers and technology eradicate understanding, ("blind us to ourselves and others"), and that such is to be avoided if we are to retain our humanness. Would this be a correct use? Sorry, it just occurred to me as describing exactly what I meant but I believe it has bliblical sources - I looked briefly online and it wasn't really helpful. Thanks! - Don

Re disagreeing, yes, but the dialog's the thing! ;-)

[Boney]

More like relying on automation to get them out of trouble vs click, click, I have control.

[AAS]

I believe it has bliblical sources - I looked briefly online and it wasn't really helpful.

John 12:40

He hath blinded their eyes, and hardened their heart; that they should not see with their eyes, not understand with their heart, and be converted, and I should heal them.

[Don Hudson]

Hi Boney - re, relying on automation....in this case I don't think so - I can't see a 20,000hr skipper with this guy's background waiting for the automation or even being confused by the Airbus - he had 6000hrs on the A320.

Thanks Boney.

I think they were suddenly overwhelmed by extreme turbulence, (formal definition of the term used here), noise from such turbulence, ECAM messages and auditory warnings. The aircraft even may have been upside down at one point...we don't know yet.

From the youtube videos and media articles I've seen/read, the Indonesians don't seem to have an explanation of how an Airbus can suddenly climb at 6000fpm when only "jet fighters" can do that...and they're right, so what caused the rate of climb? ...a 100kt updraft inside a thunderstorm. I don't get the sense that this is a performance accident like AF447, but is probably a weather accident.

[Don Hudson]

Many thanks AAS...

[DEFCON]

Don

“Trying the AF447 scenario in the sim, unstalling the wing took about 15,000ft and about 10deg nose-down, (full-forward stick) for around 45 seconds.”

Why only 10 down as opposed to say, 20, or even 30 degrees?

[Don Hudson]

Hi Kip;

Why? It started out lower when I first pushed over, but in the descent was all I could get!

ed to attach images - different sizes due screenshot copying methods

Here's what it looked like in one trial. You can see the FPV symbol almost off-scale at the bottom - the airplane is pitched down at about 12deg but the descent angle is almost 40deg. The rate of descent starts at 20,000fpm. As the wing unstalls the FPV symbol moves up, until at FL277 it is showing a descent angle of about 20deg, which, with a pitch attitude of 10deg, is an AoA of about 10deg, (vice the 30+deg it was in the initial image)...that's approximate, but sufficient for government work...

The key in every case was holding the sidestick (or the control column as the case may be), fully forward and not moving it until you know the wing is flying again, (I know you know this...but others may be reading this kind of stuff which isn't mentioned in the manuals). The exercise began at FL350; the climb to FL380 was reproduced, the THS began to move towards -13deg, (minus is the European standard in flight controls for nose-up...it means "tail down"). When the stall warning came on, the SS was placed full-forward. Recovery took 45 seconds and about 12,000ft.

[Boney]

I was referencing GDR's post.

[Kip Powick]

Don said..................

Hi Kip;

Why? It started out lower when I first pushed over, but in the descent was all I could get!

I'm confused...what does this refer to ???

[Kip Powick]

That is what I think Rich, in the Military we were taught, if caught in a nose high attitude, (nose high stall), to unload and roll toward the nearest horizon and pull to get the nose down.

I think that is 'inbred' in ex Mil pilots but for those that have never flown "whiz-bangs" or had the Military training the idea of putting an airliner over 30 degrees of bank feels really out of place.

Fortunately I have never had to "roll" an airliner anywhere near 90-135 degrees over but I think if I recognized that I was in a nose high stalled situation I would not hesitate roll and get the nose going down faster......Passengers would not be impressed but it would be better to avoid being a "lawn-dart" than worry about injured folks in the back.

The manual for the C-130 states that max bank angle is 60 degrees and that there should be no reason to be over 60 degrees. I used to take the newbies up to 8-10000 feet and do wing overs ( 120 -135 degree/steep shandels) to show them that the aircraft was still totally controllable as long as you did not fly it "ham-fisted".

[Don Hudson]

Hi Kip;

After pitching down from 15deg NU at FL380, the pitch attitude of the aircraft/sim was initially lower than ten degrees but as the descent continued, even with full-forward SS, all the airplane would give was ten degrees nose-down. Hope that helps!

Rich - we didn't try the "wing-over" technique to get the nose down. I'm not sure it would be more effective than using just the elevators, which, even in the "stall", (sim stall), they were quite responsive.

I wonder if the risk in rolling the aircraft to say 60deg to get the nose down doesn't risk a loss of control in a spiral dive? Dunno...too complex for me to figure - I'll ask my aerodynamics friend!

[ywgame]

There was a Mayday episode where an A320 out of check crashed during the test flight...investigation indicated they were testing stall protection with frozen AOA indicators (over-zealous wet wash) and the stall protection didn't work.

They had toga and max forward stick but were unable to unload the wing in a straight forward direction. EICAS indicated in big red letters that they needed to manually move the stab ("manual pitch trim required") but apparently this was either ignored or not seen...forget the altitude it started at but was not cruise. I think it would be unusual to manualy move pitch trim on an airbus during flight unless other system's failed. (mechanic, not pilot )

Kip's roll method may not work if still in normal law...I think it woud require direct law. Any thoughts?

[Woody Pusher]

I think they were suddenly overwhelmed by extreme turbulence, (formal definition of the term used here), noise from such turbulence, ECAM messages and auditory warnings. The aircraft even may have been upside down at one point...we don't know yet.

Hi Don,

Bearing in mind that we haven't seen all of the Radome, it's a guess as to when it detached.

As for the ECAM, auditory warnings and possibly fighting the effects of unusual 'g' forces, I'm reminded of the following:-

An "in context" adaption of an excerpt from Ironies of Automation, by Lisanne Bainbridge, Department of Psychology, University College London, UK.

Manual control skills

Several studies have shown the difference between inexperienced and experienced pilots making a flight path change. The experienced pilot makes the minimum number of actions, and the aircraft's flight path moves smoothly and quickly to the new position, while with an inexperienced pilot it oscillates round the target value. Unfortunately, physical skills deteriorate when they are not used, particularly the refinements of gain and timing. This means that a formerly experienced pilot who has been monitoring an automated aircraft's flight parameters may now be an inexperienced one. If he/she takes over he/she may set the aircraft's trajectory into oscillation. He/she may have to wait for feedback, rather than controlling by open-loop, and it will be difficult for him/her to interpret whether the feedback shows that there is something wrong with the system or more simply that he/she has misjudged his/her control action. He/she will need to make actions to counteract this ineffective control, which will add to his/her work load. When manual takeover is needed there is likely to be something wrong with the automated process, so that unusual actions will be needed to control it, and one can argue that the pilot needs to be more rather than less skilled, and less rather than more (sensory) loaded, than average.

Essentially, when all "hell" breaks out, you'll have a "hell" of a job trying to sort it. Especially the various implications of being shunted into Alt-1/Alt-2 or Direct Law.

The updraft AoA implications; I've got some ideas drafted for a graphic, but best left until we know what actually happened. Likewise the final vectors.

[Don Hudson]

Woody - I agree on waiting. In discussing with others the theory which I posted above regarding entry into a thunderstorm followed by the "climb" by updraft, then stall doesn't seem a viable scenario in and of itself, although one thinks the airplane would be stalled by such an encounter. The argument against the notion is, the "columns" of updraft aren't "sharp-edged" but would entrain the local air, (viscosity) such that the change in AoA wouldn't be instant. The argument against the theory was that the airplane would "adjust" through the entrained air, begin riding the column (as we would a mountain wave though much brisker!, & bearing in mind the inertia of a large mass), and once the airplane "settled" in the column the rate of climb being relative to the column would not alter the AoA significantly - we'll see what the recorders have to offer. I maintain that a sufficient AoA change would stall the wing even in normal law but I can't argue the aerodynamics or the fluid dynamics!

Thanks for the link - it sounds as though she's given AF447 a lot of thought. I think many would concur that there is a great deal of muscle-memory behind a good pair of "hands". I would also agree with her comments regarding small adjustments - that just comes with experience and it works with CC or SS configurations. Her thinking may explain Colgan as well.

[Woody Pusher]

Thanks for the link - it sounds as though she's given AF447 a lot of thought. I think many would concur that there is a great deal of muscle-memory behind a good pair of "hands". I would also agree with her comments regarding small adjustments - that just comes with experience and it works with CC or SS configurations. Her thinking may explain Colgan as well.

Hi Don,

She actually wrote the thesis in 1983! I just transposed what she wrote into an aviation idiom. I agree, she observed and understood the resulting situation very well, i.e. an automation controled operation versus an unexpected reversion to a manual process.

[Don Hudson]

Wow...pretty insightful work - right on the leading edge of the "automation revolution", so to speak. At the time of the A320 introduction, the FCOM had the statement in the introduction that the autoflight system will be engaged immediately after takeoff and disconnected on the landing roll-out. Since it was in the manual it was mandatory and there was no relief to disengage and hand-fly. That was the mentality of the time, (the Bangalore & Mt Odile accidents had not yet occurred). I can say now that we fought extremely hard to get a paragraph into the FCOM that permitted hand-flying "when appropriate" - it was a very steep, uphill battle at the time. Today, carriers have automation policies which define when full automation is required and when full disconnection is appropriate. I'm uncertain as to what time in the sim is dedicated solely to actually flying the aircraft. I recall one check pilot giving us climbing and descending "S-turns" while changing speed and configuration, all on raw data, manual thrust. It was the best exercise I'd ever done in the sim, (B767). I think such should be standard in all recurrent training exercises but valuable time is taken with the "must-do's", which don't seem to include hand-flying.

Enough editorializing...

Woody, I understand the basics of thunderstorm development but I'm struggling with the details of updrafts inside a thunderstorm - their relative size, speed, duration as they may relate say, to a sixty-ton aircraft. It seems to me that the strongest updrafts inside what may be called a "supercell", (not very precise I know), could displace such an object quite easily. Some describe such updrafts not as sharply-defined, tube-like columns of high-speed air but recognize viscosity and describe the column's "edges" (so to speak) as viscous entrainment, meaning simply that viscosity affects the surrounding air "gradually" creating a gradient of speed, (here, a horizontal gradient), and that an aircraft, rather "a wing", entering or transitioning into such a column would not have its AoA exceeded as the aircraft would have time to adjust the AoA, (pitch down, etc) such that exceeding a stall AoA would be unlikely. I think that such a transition would occur so rapidly, (A320 typical turbulence penetration speed is about 750fps TAS, in my understanding, updrafts would be in the order of 100 to 150fps TAS), that the aircraft wouldn't be able to respond in time to avoid the AoA exceedence and consequent loss of control.

Not arguing the case so much as trying to comprehend the dynamics with limited exposure to the details of thunderstorms, (but a healthy visceral fear!). I haven't been in a thunderstorm, but have had some very sharp turbulence encounters nearby one or two and can't imagine it being anything but far more violent "inside". But that's imagination, and here we're talking physics notions and calculations which are beyond me.

[Woody Pusher]

Woody, I understand the basics of thunderstorm development but I'm struggling with the details of updrafts inside a thunderstorm - their relative size, speed, duration as they may relate say, to a sixty-ton aircraft. It seems to me that the strongest updrafts inside what may be called a "supercell", (not very precise I know), could displace such an object quite easily. Some describe such updrafts not as sharply-defined, tube-like columns of high-speed air but recognize viscosity and describe the column's "edges" (so to speak) as viscous entrainment, meaning simply that viscosity affects the surrounding air "gradually" creating a gradient of speed, (here, a horizontal gradient), and that an aircraft, rather "a wing", entering or transitioning into such a column would not have its AoA exceeded as the aircraft would have time to adjust the AoA, (pitch down, etc) such that exceeding a stall AoA would be unlikely. I think that such a transition would occur so rapidly, (A320 typical turbulence penetration speed is about 750fps TAS, in my understanding, updrafts would be in the order of 100 to 150fps TAS), that the aircraft wouldn't be able to respond in time to avoid the AoA exceedence and consequent loss of control.

Don,

The transfer of a Maritime heated/saturated airmass into the atmosphere is, I suspect subject to the 2nd Law of Themodynamics. The laws of gases were something I stumbled through at school, and basically all I can remember are things like Boyle's and Charles' Laws.

My feeling is that after viewing a number of Cb anvils and the satellite images showing their central overshoots, this sort of airmass creates a viscous wall that generates the "chimney" effect. Not getting into that chimney is the most important issue, especially when transiting the ITCZ, as a non standard atmosphere could introduce a temperature incline resulting in a more rapid vertical acceleration of the entrapped airmass. I suspect this is the root cause of this particular accident.

Remember the ACARS transponder issue that cropped up with AF447? Well, I believe we have actually seen this happen in SSR coverage, where the barometric data becomes invalid (NCD) and the only data the transponder sends is GEO (GPS). So, the transponder is not "off", its just not sending dud data that could cause a TCAS problem.

[DEFCON]

Don posted a picture of the radome, which exhibits an interesting feature I think?

If we were to assume for the minute that the radome is equally preserved around its periphery, the absence of visible stress / fracture / failure of any of the attachment through holes seems to imply the fasteners failed under a load that was instant, powerful and exerted equally around its base from the inside to outside and simultaneously.

How close is the base of the radome to the forward pressure bulkhead?

[DEFCON]

Don posted a picture of the radome, which exhibits an interesting feature I think?

If we were to assume for the minute that the radome is equally preserved around its periphery, the absence of visible stress / fracture / failure of any of the attachment through holes seems to imply the fasteners failed under a load that was instant, powerful and exerted equally around its base from the inside to outside and simultaneously.

How close is the base of the radome to the forward pressure bulkhead?

[blues deville]

If this link works you can see what's immediately behind the radome of an A320. I suppose an intact radome "might" mean it did not hit the water nose low. Was there a last minute attempt at a water landing?

http://s1210.photobucket.com/user/intelmani5/media/United%20Hanger/IMG_3089.jpg.html

[Woody Pusher]

@ blues deville,

Thanks for the pics. The bottom seam was visible in the Indonesian photo, so doesn't appear that the water took it off.

From percursory examination of the wreckage photos available, the fuselage damage is consistent with a high vertical speed, underside down, impact with the sea surface, i.e. very little horizontal velocity.

[DEFCON]

"AirAsia Flight 8501: 'Screaming' Alarms Buried Pilots' Voices, Stalling Alarm Also Heard Before Crash

AirAsia cockpit recorder

Indonesian officials stand near the cockpit voice recorder of AirAsia flight QZ8501 during news conference at the National Transportation Safety Committee office in Jakarta Jan. 13, 2015. Reuters/Pius Erlangga

AirAsia Flight 8501 alarms were "screaming" as the pilots attempted to control the plane before it crashed into the Java Sea, an investigator told Agence France-Presse (AFP) on Wednesday. Investigators at the National Transportation Safety Committee (NTSC) are analyzing the flight data recorders to determine the cause of the crash.

The NTSC investigator, who did not want to be named, told AFP that the sound of the alarms, which also included one that goes off when an aircraft stalls, were heard on the plane's cockpit voice recorder. The news comes a day after Indonesia's transport minister said that the plane made an abnormally steep climb before stalling and crashing into the sea.

"The warning alarms, we can say, were screaming, while in the background they (the pilot and co-pilot) were busy trying to recover," the investigator reportedly said, adding that the warning signals went on "for some time." The investigator also reportedly said that the pilots' voices were buried by the sound of the alarms.

Transport Minister Ignasius Jonan had said Tuesday that radar data revealed that the plane "went up faster than normal speed. ... Then it stalled."

The NTSC's chairman announced Wednesday that a preliminary report on the probe will not be publicly released. However, the agency investigating the crash is expected to conduct a press briefing next Wednesday, according to Reuters. On Tuesday, investigators said that the probe will now focus on human error and aircraft damage as possible reasons for the plane's crash, after ruling out terrorist involvement.

Indonesia's meteorological agency had previously said that bad weather may have caused the crash after the plane went off radar on Dec. 28, following a request from the pilot for a change of course due to unfavorable weather.

Meanwhile, divers continue to make efforts to reach the fuselage at the bottom of the Java Sea where the bodies of several passengers are expected to be trapped. So far, 53 bodies of the 162 people on board the plane have been recovered from the sea, and 46 have been identified."

http://www.ibtimes.com/airasia-flight-8501-screaming-alarms-buried-pilots-voices-stalling-alarm-also-heard-1789688

"a preliminary report on the probe will not be publicly released"

Are we heading off the rails?

"

[Don Hudson]

"Are we heading off the rails?"

No, I don't think so although from commentary elsewhere one can see that the confidence levels are low.

One senses that there isn't the same singular "command-and-control" that we're used to in North America/Europe/Australia/New Zealand etc, and those in high positions of authority throughout Indonesian society or the military seem to make their own pronouncements with little coordination and limited understanding of what's going on elsewhere. The comparison of climb speeds with fighter-jet speeds is one such clanger, the warning systems "screaming" is another...both are wrong because (to us) they're exaggerations - fighters can do in excess of 50,000fpm straight up and warnings don't "scream" they are "heard". But that is the nature of Indonesian communications and we have conflicting messages from uncoordinated sources leaving us with the impression that the Indonesians don't know what they're doing. Here, I think they do and I think they'll get this right, partly because the Airbus is there and the NTSB is "negotiating" status. While the NTSC has "buried" at least one report, (an MD80 overrun with fatalities), they got the Lion Air B737-800 CFIT (water landing, no fatalities) right, so they're learning. You can bet that Airbus is not only "there" but keeping AF447 in mind...

To illustrate that they need to work on getting the message right, the last sentence in this report, which I beleive came out at the same time as the one above, states, "The final report on the investigation, which will be made public, must be filed within a year." It is the preliminary report which will "not be made public". We'll see...they have a week to say something formal.

(Reuters) - Indonesian divers on Thursday found six bodies near the fuselage of an AirAsia jet that crashed last month into the Java Sea, but were unable to enter the wreckage where most of the victims are believed to be trapped, a navy official said.

Days of rough weather and poor underwater visibility have hampered navy divers' efforts to recover bodies and lift the main part of the plane off the sea bed.

"It was very dark, visibility was very limited so our diving teams could not enter," Rear Admiral Widodo, commander of the navy's western fleet, told reporters aboard the warship KRI Banda Aceh. "However we still predict we can evacuate all the bodies from there."

Widodo added rescuers expected to attach giant air bags to the fuselage to lift it to the surface by Friday.

Indonesia AirAsia Flight QZ8501 lost contact with air traffic control in bad weather on Dec. 28, less than halfway into a two-hour flight from the Indonesian city of Surabaya to Singapore. There were no survivors among the 162 people on board the Airbus A320.

A multinational search and rescue operation has recovered 59 bodies so far and located both "black box" flight recorders, which will provide clues as to why the plane crashed.

The cause of AirAsia's first fatal crash is not yet known, though investigators have ruled out foul play.

Transport Minister Ignasius Jonan on Tuesday told a parliamentary hearing that radar data showed the plane had climbed faster than normal in its final minutes, and then stalled.

Three days after the crash a source familiar with initial investigations had told Reuters the plane appeared to have made an "unbelievably steep climb" that may have pushed it beyond its performance envelope.

The National Transport Safety Committee (NTSC), which is responsible for the crash investigations in Indonesia, is set to release some initial findings next week, but its full preliminary report will not be made public.

The final report on the investigation, which will be made public, must be filed within a year.

http://www.reuters.com/article/2015/01/22/us-indonesia-airplane-idUSKBN0KV0PX20150122