“Former Garuda Indonesia pilot Capt. Shadrach M. Nababan, said -based on its logbook data – that the Airbus A320-200 serving AirAsia flight QZ8501 had experienced problems as much as nine times on its auto rudder trim limiter flight control in 2014.
Three days before crashing on December 25, 2014, flight QZ8501 experienced a ‘return to apron’ twice, according to Shadrach…”
Q: Regarding the continuous left turn, and reversion to alternate law, there were reports a number of years ago of FAC (flight augmentation computer) faults on A320s resulting in “runaway” rudder trim. From Youtube (not “runaway”, but … http://www.youtube.com/watch?v=MT0NJiRFA1s My understanding is that FAC failure will also result in a reversion to Alternate2, with a number of protections being lost.
A: You got something there… Ironically a local media called me today and asked about MELs related to:
AUTO FLT RUD TRV LIM (and 2)
ELAC 1 FAULT
Rudder travel limiter 2 fault identification and MEL Cat C allowances
AUTO FLT RUD TRV LIM SYS
FAC 2 FAULT
This… they said was from the aircraft’s write up…
Q: “Safety Recommendation 2010-092 It is recommended that Airbus alert all operators of A320-series aircraft of the possibility that an electrical power generation system fault may not be clearly annunciated on the ECAM, and may lead to uncommanded rudder trim operation.”,
A: Uncommanded rudder command or rudder trim is being suspected.
Q: A dual FAC failure seems to me one factor that could explain the event after the climb as it seems that the aircraft kept structural integrity all the way to the impact. Another problem is that with both FACs failed, the flight control laws revert to ALT w/o protections. It’s not – obviously – the explanation. It just shows how drastic and how complicated the chain of events could have been on this accident. Anyway, the failure(s) must have been severe, given how redundant the systems are on a modern jet. It’s one of the reasons I’d like to know whether the engines were running after / during the climb.
A: Dual FAC fail or fault could have caused reversion to ALTN NO PROT… Even Yaw Damper failure could have caused the above. If it’s an FAC 2 fault only, I wouldn’t suspect Yaw Damper failure… But ELAC2, and FAC2 swap (with another aircraft) and the write ups… does raise my eyebrow…
Q: I thought that even ALT2 had some protections left, but I’m always happy to learn.
A: A320 has a different albeit similar reversion chain… Dual FAC fail, Dual HYD (Green & Yellow) fail, Yaw Damper Failure = Pitch ALT (REDUCED PROT), ROLL DIRECT, YAW MECHANICAL
ALT NO PROT (ALTN 2) in A330 would translate in A320 to…
Pitch: ALT NO PROT
Double ADR Fail (with 1 fail not through self detection of VCAS or M disagree)
Triple ADR Fail
Double SFCC Fail
Double HYD fail (Green & Blue)
This is not what we seem to be looking at ALT RED PROT not ALT NO PROT.
Q: What we call * ELEC EMER CONFIG (on BAT) * is no joke and at 60 kt indicated, I honestly doubt the RAT would deliver anything.
A: Let’s just assume for the moment that the engines are running to the very end… 😉 *hint hint*
email@example.com (Wed 21 Jan 2015)
Q: I believe Mandala499 has pondered an inflight breakup.
A: Pondered only… leaks from within currently indicate recordings were all the way to water impact… this effectively rules out inflight breakup involving separation of the rear fuselage. The photos of the wreck, all seem to indicate a nose high water impact with left bank… but this will have to be confirmed by the FDR.
Q: How can the cockpit and the rest of the fuselage come to rest so far apart on only 100 feet deep water? After separaion they both fill with water in seconds and fall to the bottom.
A: If it was a flat attitude, it’s difficult… but a nose high altitude can make this possible it seems…
The media mayhem have stopped for me for the past 2 days providing much needed relief, rest, and time to look at the information gathered.
There is now a debate within the stakeholders on whether or not to look for the FOQA data (which includes the ECAM messages, which on this aircraft, is (according to sources in the airline) not recorded in the FDR. The FOQA data would be stored in the FDIMU in the avionics bay in a CF card… I am told the CF data, if treated the same way as the FDR from site-retrieval to the lab, would have a high possibility of having the data intact.
Let’s see how things will pan out over the next few days…
“An Indonesian search official said Friday that the crashed AirAsia jet’s fuselage will be lifted to the surface after sea conditions again prevented divers from examining the large chunk of wreckage.
National Search and Rescue Agency chief Henry Bambang Soelistyo said that rescue teams discovered more wreckage despite the strong current and poor visibility.
“Apart from the fuselage, we found what we suspected as the aircraft’s cockpit and also an engine,” he said. “We also found what seems to be a passenger seat in which we thought there still bodies tied on it.”
He did not specify whether or not the seat was inside the fuselage section that sits on the seabed at a depth of 28 meters (92 feet). The 30-meter-long (100-foot-long) part of the plane body with a wing attached was sighted Wednesday.
Rescuers believe that many of the bodies are still inside the main fuselage.
Soelistyo said the failure of the underwater examination of the wreckage left no option but to lift the fuselage, either by using floating balloons as the tail part was lifted early this week, or using cranes from tugboats. He did not say when the operation would start.
He added that one victim’s body was recovered on Friday, raising the total to 51…
..Earlier Friday, chief of operation of the agency, Suryadi Bambang Supriyadi said the wreckage that appears to be the cockpit was located by sonar imagery about 500 meters (yards) from the fuselage and partly embedded in the mud.”
Just spoken over the phone with the Commander Task Group for underwater search operations on board the MV Swift Rescue, SLTC Chow Khim Chong. He described to me how their sonar first detected the wreckage about 2km from where the tail was found earlier. They then sent the remotely operated vehicle to have visual confirmation before informing BASARNAS, the Indonesian search authority. The wreckage with wings was about 26m long. I asked Khim Chong to convey my thanks and appreciation to his crew. I’m sure Singaporeans are proud of them for their hard work. Attaching an audio-clip of the phone call.
– Ng Eng Hen
“Reports from the field are trickling in… There is means to guarantee that the following make sense or accurate. This is a speculation warning.
From the description I am getting it appears that the horizontal stabilizer had separated from the rear fuselage, which separated from the rest of the aircraft, at around FL220 (where the recorded ADSB altitude is only GEO alt, and no more barometric).
From the description of the SAR team, it is unclear if the FDR was found on the sea floor below the horizontal stabilizer or the aircraft wing. 1 FA found strapped to his seat, indicates that those onboard were anticipating something.
The above may be obvious to some already, and this news from ‘inside’… gets me baffled once more…
Still a great deal of obfuscation going on and it seems to me that one of the most important things still unfound in this accident is absolute truth. The obfuscation by the SAR team isn’t helping. They, and the military brass seems to be seeking glory with every single discovery. Thankfully, they are not the ones doing the investigation, and sources from inside the search team has indicated that the locations reported are so far accurate.
Q: If that’s what happened I guess this wasn’t just a simple stall like AF447 as in that kind of a flight condition there shouldn’t be high enough forces to damage the aircraft so badly…
A: Well, -20000fpm, and the last recorded valid barometric info (I just received the info) on the ADS-B, was at FL235, with -15,681.25fpm, at the beginning of a tight left turn. Seems that the load factor protection of the FBW had failed… the question is, what caused the failure.
… I have seen the data and there was a wide left 180 (with a stall in the middle) followed by… a tight left orbit before the data stopped…
Q: Does this normally degrade with degraded flight control law (normal to alternate to etc.) or is it supposed to always be present?
A: If it goes to ALT with reduced protection (load factor protection available), the icing argument, makes sense, but doesn’t explain the breakup… If it goes to ALT with reduced protection then go into an upset, this needs opening the books (which I can’t do effectively at the moment).
“Divers have retrieved the cockpit voice recorder of crashed AirAsia flight QZ8501, according to reports…”
“…Henry Bambang Soelistyo, chief of Indonesia’s search and rescue agency, says the flight data recorder was brought to the surface by four divers early Monday morning. He says the search continues for the cockpit voice recorder…”
“Cockpit voice recorder located 20m from flight data recorder, says official”
Update – 11 January 2015
“…Forty-eight bodies have been retrieved so far. Search teams believe most of the remains may still be inside the fuselage of the plane, which has yet to be found…”
“THREE ships equipped with ping detectors received pings from the same location,” said Ridwan Djamaluddin, from the Agency for the Application of Technology, whose ship was involved in the search.
He said the ping came from a location about one to four kilometres from where the aircraft’s broken tail section was retrieved on Saturday. “We are confident it’s from the black box,” he said, referring to the voice cockpit recorder and the flight data recorder…”
“If one assumed that the aircraft pancaked, or even broke up attempting to ditch, you would expect that the remainder of the aircraft, particularly all the concentrated mass components, ie, the dense and heavy bits, like engines, apu, mlgs, nlg, and if they separated from their mounting trays, the cvr, fdr etc, and the other larger major components like ths, outboard wing panels, and centre section, would be, indeed must be, immediately proximate, regardless of currents. So far, that does not seem to be the case.
There is no evidence, at this stage, of any other major component wreckage, anywhere, let alone anywhere near the location of the tail. It has been reported that a suspected pinger is over a mile away.
The reported condition of the recovered bodys (at this stage less than one third) suggests relatively low “g” conditions. The leaked mode “s” data showed high rod at much below cruise level.
Taken together therefore, these observations suggest strongly to me, the high probability of an in flight breakup, not a whole aircraft experiencing surface induced structural disruption.
My viewing of the recovered upper empenage and fin, and lower rudder, suggests to me, that the ths, and it’s mounting structure (including apu mounting structure and apu) most likely separated from the upper empenage by downward bending with pitch down torsion.
If that is the case, it would have taken tremendous downward ths loading of the support structure to do that, which suggests to me, probable breakup during pull-up, attempting recovery from a significantly pitch down attitude, at high speed (high dynamic pressure), probably at a relatively low altitude, ie, between FL200 – FL100.
Under such conditions, if the ths separated first, with the aircraft otherwise still “whole at that instant”, the remainder of the aircraft would immediately, and violently, “tumble in the pitch down direction”, with high angular velocity. The weakened empenage would “immediately” tear off, and the remaining fuselage aft of the wing, and the fuselage forward of the wing, would then both rapidly separate from the wingbox, probably before the pitch axis had even passed through the vertical. In the same timeframe, the pylons would fail, the engines would separate, and the outboard wing sections would fail in downward bending and torsion overload, and separate, probably at or just outboard of the pylons.
The schredded wreckage would then descend. If that be the case, the greater the altitude of the breakup, the greater the dimensions of the resulting debris field. The foreward section of the fuselage, and the remaining aft section of the fuselage, may have remained relatively intact, and may still contain most of the occupants.”
AirAsia Update – 7 Jan 2015
AirAsia Indonesia Flight QZ8501 UPDATE (as of 7th January 2015 8:00 PM (GMT+7)
SURABAYA, 7 JANUARY 2015 – The National Search and Rescue Agency (BASARNAS) Republic of Indonesia today confirmed that the SAR team retrieved a visual confirmation of the tail part of QZ 8501’s aircraft. The visual confirmation was made following underwater documentation of the aircraft’s tail and small wreckage, which showed the plane’s registration number (PK-AXC), captured by the SAR team’s sea divers.
The tail part was found in the additional focus search area (approx. 30 kms from the primary focus area). The SAR operation is still underway as the weather is reported to be clear with good underwater visibility for the divers to continue observation.
Sunu Widyatmoko, Chief Executive Officer AirAsia Indonesia commented, “We would like to extend our appreciation to all authorities and personnel that has been involved in the SAR operation. Today is the eleventh day and the latest finding is indeed an breakthrough for all of us who have been anxiously waiting for further development on the SAR operation.” Following the latest finding, BASARNAS confirmed that the later SAR operation will be focused in this area to see if there are any trapped remains that must be recovered as well as the continued search for the black box.
Earlier today, Indonesian Navy Commander of the KRI Bung Tomo-357, Lieutenant Colonel Ashari Alamsyah officially handed over the debris and passengers belongings of QZ 8501’s flight that were found in the search area to the Deputy Commander of Indonesian Naval Aviation Unit, Colonel Yuwono at SAR Operation center in Juanda International Airport. As for the next phase, debris will be transferred to Indonesia’s National Transportation Safety Committee (KNKT) for further investigation.
This morning, BASARNAS also confirmed to have recovered one more remain from the search area. The remain is still in Pangkalan Bun, waiting to be transported to Surabaya for further identification process. Meanwhile, the Disaster Victim Identification Police Department Republic of Indonesia (DVI POLRI) today announced that they have identified 8 more remains of QZ 8501 passengers as: Ratri Sri Andriani (female),Rudy Soetjipto (male), Jou Christine Yuanita (female), Soetikno Sia (male), Ruth Natalia Made Puspita Sari (female), Nico Giovani (male), Indahju Liangsih (female), Stephanie Yulianto (female). AirAsia Indonesia officially handed over the remains to the respective families at Bhayangkara Hospital, Surabaya this afternoon.
To date, BASARNAS confirmed to have recovered a total of 40 remains of which 24 remains have been identified by DVI POLRI and 16 remains are still being identified.
Search teams looking for underwater wreckage from crashed AirAsia flight QZ8501 have located the tail of the aircraft, the section where the crucial black box flight recorders are housed, Indonesia’s search and rescue agency chief says.
Bambang Soelistyo, the chief of Basarnas, Indonesia’s search and rescue agency, told reporters in Jakarta recovery teams found the tail of the plane in the Java Sea.
“We have successfully obtained part of the plane that has been our target. The tail portion has been confirmed found,” he said.
AirAsia Update – 6 Jan 2015
“…This evening, BASARNAS also confirmed to recover two more remains from the focused search area. The two remains are still in Pangkalan Bun, waiting to be transported to Surabaya for further identification process.
Meanwhile, the Disaster Victim Identification Police Department Republic of Indonesia (DVI POLRI) today announced that they have identified 3 more remains of QZ 8501 passengers as: Indra Yulianto (male), Hindarto Halim (male), Jou Brian Youvito (male). AirAsia Indonesia officially handed over the remains to the respective families at Bhayangkara Hospital, Surabaya this afternoon.
To date, BASARNAS confirmed to have recovered a total of 39 remains of which 16 remains have been identified by DVI POLRI and 23 remains are still being identified…”
The Jakarta Post
Indonesian officials said Saturday that they were confident wreckage of AirAsia Flight 8501 had been located after sonar equipment detected four massive objects on the ocean floor.
The biggest piece, measuring 18 meters (59 feet) long and 5.4 meters (18 feet) wide, appeared to be part of the jet’s body, said Henry Bambang Soelistyo, chief of the National Search and Rescue Agency.
Though strong currents and big surf have prevented divers from entering waters to get a visual of the suspected fuselage, officials are hopeful they will find many of the passengers and crew inside, still strapped in their seats…
The objects on the seafloor were discovered Friday and Saturday, and an Indonesian Geological Survey vessel was used to assess their dimensions, Soelistyo said.
In addition to what appeared to be a significant part of the plane’s body, chunks of debris found in the target search area measured up to 12 meters (39 feet) long.
Other suspected plane parts were seen scattered on beaches during an aerial survey, Soelistyo said…
Strong currents and towering waves as high as 4 meters (13 feet) have slowed recovery efforts, scattering bodies and debris in all directions. The discoveries so far include an emergency exit door and slide, as well as a backpack with food and a camera inside.
As part of the investigation into the crash, autopsies will be carried out on some of the bodies, including the pilot and co-pilot, whose remains have not yet been recovered, said Budiyono, who heads East Java’s Disaster Victim Identification unit and, like many Indonesians, uses only one name…
2 Additional Large Objects Found by USS Fort Worth
Q: The news is stating 4 large pieces of the plane have been identified/found/located, are these very close to each other?
A: 3 within 30-50 meters of each other and 1 within 300-400m of the other, that is what I heard or misheard on the press conference 18 hours ago or so.
Q: Several threads ago you gave information which was transmitted from the aircraft. Has this data been able to be validated by cross referencing with other data which either qualifies the data as good or suggests it is maybe questionable?
A: I cross checked this with someone involved in the wreckage search, and the position “made sense” after allowing for debris drift. I have since obtained more on the so-called Mode-S transmissions from the aircraft, and trust me, it is NOT a pretty picture. Honestly, it makes AF447 look like a doddle.
Q: The AD did not concern a “computer glitch,” but rather an issue with frozen AoA vanes which, under the right conditions, can cause Alpha Prot to activate and the flight control system to therefore command nose-down pitch rates.
A: People I believe are incorrectly referring to this Red OEB as they are looking for anything to quickly solve the cause. The OEB deals with the situation where the AoA probs which are an input to the flight control computers are frozen at an angle of attack, and the aircraft mach number is increased. This should not be an issue in the cruise when mach is relatively stable.
What the flight control computers see is a higher angle of attack on two or more probes which is normal for lower speeds, however as they aircraft accelerates the AoA should decrease. By having two or more of them them frozen (unable to rotate), AoA remains unchanged for the speed, so the flight control system will lower the nose to reduce the AoA. If it is the case of a single one being frozen, the aircraft will vote the incorrect one out, this problem only occurs when there are multiple incorrect inputs.
Q: implies a very definite nose-down attitude.
A: No it does not.
Q: Forgive my ignorance, but just how out of the ordinary is this?
A: Depends on the level they are at, it is not uncommon to have -60 deg C in cruise in the tropics, if they are looking at cloud tops of a mature CB, it can reach the best part of 20-30,000 above normal cruising altitudes in the tropics. The tropopause is up around 55,000 ft at the moment in the area, which is normal this time of year.
Q: The general area of the main wreckage relative to floating debris varies not just with time (currents) but also depends highly on what exactly happened to the plane in the first place.
A: The parts of the cabin that have been recovered in my view show signs of vertical deceleration.
LB Note: As best I can determine, Air Asia did not have Airbus ACARS maintenance subscription nor on-line engine monitoring.
When avoiding CBs ahead you can ask for a clearance in many different ways.
– You can ask for a new specific heading: “Callsign requesting left/right turn heading xxx due to weather” You have to ask again when a further deviation is required.
– You can ask for a clearance to proceed offtrack: ” Callsign requesting up to 30NM right/left of track due to weather” This request allows you to basically to use headings on your own as long as you stay within the mileage which was granted.
In most parts of the world it is way easier to obtain a lateral deviation clearance than a vertical. Vertical separation is almost everywhere 1000′ and the limiting factor.
Lateral separation is around 5NM in terminal areas up to 100NM or more in remote areas. Take a look on flightradar and skyvector to get am impression of airway density in different parts of the world.
QZ8501 was filed on airway M635. The next airway towards the southwest is airway L511. It is more that 70NM southwest of M635. This enables the controller to use the airspace between the airways for traffic avoiding CBs…
Safety is first!
… Bravery… Being a pilot does not require bravery. But people are different. Sometimes I observe other traffic (on the nav display) which is very close to a build up. They are in a position where I would not want to be. Are they brave? I don’t know. They might be less sensitive to CBs than I am. But I really don’t like build ups that much.
The pressure on pilots might be different, depending on where you work. This was on CB cluster we were deviating around. And it looks like that we did not received a clearance for that (Africa).
Q: Thanks again for your contributions. What are the circumstances under which you will climb to better see what you are trying to fly around?
A: This depends on lots of factors: Day, Night, Moonlight or not, what type of cloud am I in, tropopause height, relative position to build ups (if any), wind direction, … But in the end I don’t have to see anything, because the weather radar is a pretty good tool to avoid the dangerous stuff.
Q: Will the weather radar display hail that gets kicked out of the tops and can come down well away from the storm center?
A: You need to know the structure of a cumulonimbus cloud to identify dangerous areas. The reflectivity of precipitation depends on droplet type (rain, wet hail, dry hail, ice crystals). So you need a combination of weather radar display and knowledge to identify hail areas.
It is better not to fly in the areas where the hail will come down obviously. The hail itself will not be kicked out of the tops, but it will be in the cloud, next to the cloud and below the anvil. During cruise, the part under the anvil is the one you want to avoid because here you will find hail furthest from the cloud. You do not want to fly too close to the CB anyway.
Here is an open document, which contains some nice images, drawings and weather radar information:
“To summarise, the flight was in a northwesterly heading and probably climbing from FL320 to its cleared level of FL340. The crew had already initiated a deviation to the left of bad weather just before the accident, and meteorological data show some vigorous convection – and therefore moderate to severe turbulence – in the immediate vicinity. At least two other flights also appear to have taken a (wider) deviation. Upper air observations and model data suggest that icing conditions were also possible. Radar data show that the aircraft’s groundspeed was unusually slow for the conditions observed.”
The transponder today is no longer a simple device, it is a complicated transmitted connected to numerous systems designed to provide different levels of data to ATC and other aircraft.
In its most simple mode, the transponder will return a ping to a radar without any altitude information, and the time of flight and azimuth of the ping is used to generate an arc of that distance from zero ft at maximum distance to directly above the radar head where the aircraft must be. Next to useless as the height of the aircraft is needed to establish where the aircraft is on that arc.
The error with this position information is the similar to position errors with a VOR, the airways need to be calibrated to account for position errors. Calibration is needed to establish the ground station and site effect error, the can be as much as 2 degrees which at 200 nm from the radar head can mean a position error of around 7 nm.
Mode C is taken from the aircraft air data system, if the air data system is compromised, eg probes or ports blocked, the transmitted encoded altitude can be in error.
Globally the datalink standard ADS-B out uses is the 1090 MHz Mode S Extended Squitter (1090 ES) (some regional areas also use VHF Data Link Mode 4 (VDL-4) and Universal Access Transceiver (UAT)). ATC has two types of ADS-B, ADS-B RAD : ADS-B for Radar Airspace and ADS-B NRA : ADS-B for Non Radar Airspace. Data for the ADS-B out comes from a different system again, it comes from the navigation system, the system will normally provide 8 labels to the transponder from the GPS, GNSS Altitude (Msl) Feet, GNSS Latitude Degrees, GNSS Longitude Degrees, GNSS Ground Speed Knots, Vertical Figure Of Merit Feet, Vertical Velocity Feet/Min, EPU Estimate Position Uncertainty/ (ANP), Actual Navigation Performance, Horizontal Figure Of Merit, GNSS Height Feet. It can take up to two seconds for each ADS-B out packet to be sent, and for Routine Surveillance or Navigation the ATC equipment will process 95% of the ADS-B data within 22.5 seconds, and 99.996% within 45 seconds.
Bottom line, with the delay in generating and transmitting the ADS-B packets, you need to be aware of the limits of the different pieces of information, what their source is, and what the errors are in each system before drawing conclusions.
Also need to keep in mind is you are looking at SSR data, the altitude information is from the air data system on the aircraft, if its ADS-B, the altitude information is from the GPS/NAV system.
The radar screen image provided in a previous thread showed the aircraft as an open circle, that means the data source was SSR, ADS-B derived positions, aircraft are displayed differently (like a fly by waypoint symbol tilted by 45 deg).
AirAsia flight QZ8501: Crucial black boxes may not be found with wreckage after plane ‘split or cracked’ during crash
Five large objects have been found at the bottom of the Java Sea about 90 nautical miles off the coast of Borneo, and experts believe them to be parts of the Airbus A320-200 that plunged into the sea on route from Surabaya to Singapore last Sunday.
At about 18 metres (59 feet) long, the largest piece suspected to be the fuselage of the plane – but bad weather and strong currents have prevented searchers from making the relatively shallow 30-metre dive to verify this.
Fransiskus Bambang Soelistyo, the head of Indonesia’s search and rescue agency, said the focus now was to reach that fuselage, where many bodies could still be strapped in to seats. “Our priority is to dive in the location we suspect parts of the plane to be,” he said.
But Soelistyo said none of the ships searching the area have detected any “pings” – locator signals sent out by black boxes in the event of a crash…
Air Force Lt Col Johnson Supriyadi, a search and rescue official co-ordinating the operation, said it now looked like the boxes, located in the tail of the plane, had broken away from the rest of the wreckage.
“Based on the finding of pieces of debris it looks like the body of the aircraft split or cracked and was separated from its tail,” he said…
-03° 38′ 39″ 109° 43′ 43″ (degrees minutes seconds)
This is about 2.5nm South East of the last SSR/ADS-B location (Google Maps measures 3.03 statute miles = 2.63nm)
In my screen grab [above]:
– the lower yellow start marke the tail section (and the blue annotation is the distance from the purple star)
– the purple circle is the last lat/lon from the SSR (ADS-B),
– the purple star is the approx location from the primary radar image.
– The red box is supposed to be “Most Probable Area 2″,
– the black tilted rectangular outline is the left (Western) section of the “Underwater Search Area”.
– The yellow diagonal line is Route M635 between TAVIP to RAFIS.
– The black diagonal line is the FR24 estimated flight path (the inverted teardrops are individual extrapolations from FR24 after the last valid ADS-B data data they received)
[ignore the white square, the blue square, the Northern yellow star, and the green diagonal line]
The photo of inside tells the most: it is taken inside aft fuselage looking from front towards the tail end and considering that light comes from the top of photo, I believe camera was held reasonably level. Therefore, this part of tail section probably rests leaning on vertical stabiliser with its right side on the bottom (left side exposed – photographed) Right half of horizontal stabiliser pushed into the mud or is (partially) broken away-fuselage rests half inverted to the right side-approx. 130 deg. from normal. Interior shows parts of THS mechanism, that moves-trims horizontal stabiliser via jackscrew. It appears it is in extreme position ANU, (leading edge to the bottom) but cannot say for sure as mechanism looks broken and fuselage skin severely distorted. Am surprised that CVR / DFDR were not found, as they are installed very close to position, from where the photo was taken. I assume that part of the fuselage is not in the same piece with the structure photographed.
AD No.: 2014-0266-E – Date: 09 December 2014
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.
AIRBUS A320 (PDF) Materials
**Disclaimer: The Smartcockpit PDF files are for training purposes only and may be obsolete.**