Lion Air 737 Missing

[Undried Plum]

Looking at the graph, it appears that they were fighting the trim and the trim won.

Undoudtedly there were other factors at play, but the very extreme departure in the last few seconds of the recording suggests that there was a massive pitchdown which is most unlikley to have been a deliberate pitch input at those very high speeds.

[Slasher]

Well now you're speculating Plum. Your interpretation of the graph as being possible ASI/Alt problems as I said before has merit, but a suggestion now of trim indicates a misuse in combination with the primary problem or perhaps a runaway - but the stab trim cutout switches on the pedestal would clear that.

I can't remember if the 737 had associated trim problems with **** ASIs except if the A/P was in CWS - then you'd be fighting autotrim. Nor have I any idea what the flight control/AP hookup design is in the 737 Max either.

We'd have to see exactly what the dIspatched MEL(s) was/were to get a clearer picture. As it is I'll wait and see what the DFDR and CVR say.

[Cacophonix]

Indonesian search and rescue workers believe they have found the fuselage of a Lion Air passenger jet that crashed with 189 people on board, and are also trying to confirm the origin of an underwater "ping" signal, officials said on Wednesday.

Indonesia's military chief said he believed the plane had been located, and a transport safety official said divers would be sent to confirm the origin of a "ping" signal picked up by a search and rescue team late on Tuesday.

"We strongly believe that we have found a part of the fuselage," armed forces chief Hadi Tjahjanto told broadcaster TV One.

Speaking on board the navy ship KRI Rigel, navy official Colonel Haris Djoko Nugroho told broadcaster TVOne that a 22-metre long object had been found in waters about 32 metres deep, and a sonar was being used to identify it.

Divers would also be sent to check, he said.

The accident is the first to be reported involving the widely sold Boeing 737 MAX, an updated, more fuel-efficient version of the manufacturer's single-aisle jet.

The plane's blackboxes, as the cockpit voice recorder and flight data recorder are known, should help explain why the almost-new jet went down minutes after take-off.

Amid media speculation over the airworthiness of the aircraft, the transport minister suspended Lion Air's technical director and several technicians to facilitate the crash investigation.

The suspended technicians "issued the recommendations for that flight", the ministry said in a press release. It did not say how many technicians had been suspended.

An official of the national transport safety panel has said the plane had technical problems on its previous flight on Sunday, from the city of Denpasar on the resort island of Bali, including an issue over "unreliable airspeed".

Privately owned Lion Air, founded in 1999, said the aircraft had been in operation since August and was airworthy. The pilot and co-pilot had 11,000 hours of flying time between them, it said.
Lion Air chief executive Edward Sirait has acknowledged reports of technical problems with the aircraft, but said maintenance had been carried out "according to procedure" before it was cleared for flight again.

https://www.msn.com/en-gb/news/uknews/s ... spartanntp

Caco

[Slasher]

An official of the national transport safety panel has said the plane had technical problems on its previous flight on Sunday, from the city of Denpasar on the resort island of Bali, including an issue over "unreliable airspeed".

IIRC the 737 could depart under MEL with one ASI inop (but not the standby ASI) PROVIDED IT WAS PROCEEDING TO A BASE WHERE REPAIRS OR REPLACEMENT CAN BE MADE.

Even if Lyin' had bent the rules, the second loss of a primary ASI shouldn't cause a major concern, and a return to the dep airport is of course fully justified.

[Slasher]

ec04397d-2a46-406f-a89f-cb4861402e12.jpg (126.63 KiB) Viewed 424 times

[ian16th]

Question about flight data recorders.

If a FDR reads and records a factoid such as airspeed or altitude, is it a recording of the indicated airspeed or altitude or is there some way of recording the actual?
If the later, how is it calculated and why aren't the crew informed of the true situation?
If it is the former, and it is wrong, how is this known?

[Slasher]

Depends on the inputters to the DFDR. I can't recall the 737 but the 320 inputs are IRS, ADR and FMC data. This includes GPS G/S, GPS alt, true track, mag heading etc. If all 3 ADRs are faulty it will record the faulty data (Mach, Airspeed, Alt, etc)

[Boac]

Slash - those FR24 readings are odd. A lot of the 'FPMs' are pure binary values - 256, 512, 1024, 2048??
#If I read them right there is very little track change and the whole thing only lasts 1 minute.

[Slasher]

Yes I noticed that too Boac. I don't know if it's an ADS-B Out thing or not. Given the amount of data and being only a minute I'd guess binary would be the only way. Again I don't know.

Not that the readout above is of the final minute before impact. Best go to Undried's graph on the prev page for a full picture before it.

[Slasher]

That should read Note that the readout...

[Mrs Ex-Ascot]

From this report in the Guardian it seems that the pilots the day before should not have pressed on and RTB as they initially intended. They would have saved a lot of lives if they had.

https://www.theguardian.com/world/2018/ ... ane-around

[Boac]

Too many unknowns, Mrs ex-A. It may be that they, having got the beast under control, decided to continue below RVSM airspace to destination, and maybe felt they had diagnosed the problem. Assumption is that:-
dest was a maintenance base
they snagged the ship there
it was 'worked on' there

I would not rush to criticise the previous crew based on what I know, especially since they raised a snag. You (or the Grauniad) could equally argue that had the defect been fixed...............

[Boac]

The wreckage being recovered is confirming a high-speed crash into the sea, such that it is not expected any human remains will be those of a complete body. This picture of the main gear shows the damage.

5694514-6345661-image-a-66_1541166297257.jpg (88.25 KiB) Viewed 344 times

According to the Daily Wail Indonesia has ordered the inspection of all 737 MAX following apparent reports of previous 'display and control' difficulties.

[Cacophonix]

The head of Indonesia’s National Transportation Safety Committee, Soerjanto Tjahjono, says the “black box” data recorder from the crashed Lion Air jet shows its last four flights all had an airspeed indicator problem.

Tjahjono and investigator Nurcahyo Utomo told a news conference that the problem was similar on each of the four flights, including the fatal flight on Oct. 29 that killed all 189 people on board.

https://eu.usatoday.com/story/news/worl ... 889396002/

From the excellent avherald site...

http://avherald.com/h?article=4bf90724

The airline reported the aircraft encountered a technical problem, the crew was about to return to Jakarta. There had also been a technical problem on the previous flight, this problem however was fixed (editorial note: the aircraft remained on the ground in Jakarta over night for 8 hours prior to the accident flight, there is a write up circulating in the Internet only claiming the aircraft had experienced unreliable airspeed and altitude on the previous flight, the captain's instruments were identified faulty, control was handed to the first officer and the flight continued to destination below RVSM airspace - we removed this write up repeatedly from our reader comment board because of its unverified nature and because it supposedly contains names of flight crew). The captain had accumulated 6,000 hours of total flight experience, the first officer 5,000 hours.

On Oct 30th 2018 the airline indicated they are going to accept whatever sanctions will be issued including a grounding. As of current inspections of all aircraft under supervision by the Ministry are underway.

On Oct 31st 2018 the airline stated they have dismissed the technical director and assigned a new technical director.

On Nov 1st 2018 the airline confirmed one of their maintenance engineers was on board of the aircraft during the accident flight. This was an "anticipatory measure" in the event of technical problems with the new aircraft. As such, "the presence of the technician has nothing to do with the condition of the aircraft before taking off."

Indonesia's KNKT (aka NTSC) reported the crew requested to return to Jakarta shortly after takeoff, when the aircraft climbed through 2000-3000 feet MSL about 3 minutes after takeoff, the request was granted by ATC. The KNKT is still looking into the causes of the request to return. About 8 minutes later radar contact was lost. The blackboxes are at an estimated depth of 30 meters, attempts to reach and recover the black boxes are underway.

Late Oct 30th 2018 the KNKT reported in a press conference that they have listened to the ATC audio recordings and heard the request to return. However, The KNKT will first compare with the black boxes and verify that the recording matches what happened to the aircraft before releasing such information.

On Oct 31st 2018 the KNKT reported in a press conference, they are about 70% certain the pings being received since Oct 29th come from the aircraft's black boxes. The location appears to be within 3 kilometers of the current search area. Resources are being deployed to examine and retrieve the source of the pings.

On Nov 2nd 2018 the KNKT reported the black box recovered on Nov 1st 2018 was the Crash Surviveable Memory Unit (CSMU) of the flight data recorder storing 25 hours of flight data. However, as the flight data recorder has been split, additional work is needed to read the data out. The unit is being cleaned and recovered at the KNKT recorder lab in Jakarta.

On Nov 4th 2018 the KNKT reported the FDR has been successfully read out. It contained 1800 parameters spanning 19 flights including the accident flight. Analysis of the data has begun. The KNKT is committed to release preliminary findings as soon as possible.

AirNav Indonesia, ATC provider, reported the crew requested to return to Jakarta, however, did not declare emergency. The aircraft did not turn following the clearance to return, radar contact was lost subsequently.

Boeing reported Indonesia's Ministry of Transport has confirmed the wreckage of the 737 MAX 8 has been located conducting flight JT-610. Boeing is saddened by the loss of flight JT-610 and expresses condolences to the families. Boeing stands ready to provide technical assistance to the accident investigation.

On Oct 31st 2018 a local fisherman reported they (he and his friends) were out on the Java Sea to fish for shrimps when they observed a white airplane with an orange pattern in some distance, the aircraft was flying unusually low. The aircraft appeared to roll in for a turn when it shook and swooped sharply and impacted the waters of the sea. Immediately after a sound of thunder or explosion occurred. They were afraid of approaching the source of the sound and decided to return to the coast which was about 3 hours away. After arriving at the coast they saw the coast was crowded with many residents looking out over the waters, there were emergency vehicles and policemen in the crowd. They talked to a policeman and told him about their observation, police asked them to show them the crash site. After a trip of about 3 hours back to the location they found debris, body parts and oil slicks on the surface of the water. Soon after many more ships arrived at the scene.

According to ADS-B data transmitted by the aircraft's transponder the aircraft departed Jakarta's runway 25L at 06:21L (23:21Z Oct 28th), never climbed above 5400 feet remaining between 5200 and 5400 feet for about 6 minutes before losing altitude and disappearing from radar about 12 minutes after departure at about 06:33L (23:33Z) about 35nm northeast of Jakarta's International Airport.

Caco

[Alisoncc]

All reports to date seem to indicate problems with the ASI. It would be sad indeed if the end result turns out to have been a blockage of the pitot/static lines. Possibly flying insects taking up residence therein. That's been catching out pilots for an awfully long time. Computerising the systems just makes it even more dangerous.

Alison

[Pontius Navigator]

Alison, and heavy rain too.

[Undried Plum]

Is Lion Air one of those outfits which discourage crews from hand-flying their aircraft as a matter of routine?

How many hours (minutes?) of actual physical hands-on flying time would these guys have had in the last 30 or 90 days?

If they are just button pushing flight deck attendants, then perhaps it would be asking too much of them to switch off the **** automatics when all is turning to a pile of pants?

Is it too much to hope that modern 737 drivers might be of the calibre of the Gimli Glider pilot(s) or Eric Moody or Sullenberger?

[Boac]

It would be a very rare event for all three (independent) ASI systems to have problems together. The major issue is confusion on the flight deck - 'which one/s are right' and good crew co-ordination is needed. If it is this simple, then really it should have been sorted out at take-off when the 3 would have disagreed and control allocated to the side with the 'correct' readings. There has to be more.

[Alisoncc]

Boac, three separate pitot heads and three separate static lines?

If static lines aren't protected then a swarm of wasps can easily block as many lines as are available. Get some very funny readings if partially blocked by what might be moving objects, with each line giving different static variations over time.

Have fond memories from my time flying in similar places to Indonesia. There was a little wasp who on finding a nice round hole would pop in, lay a few eggs and block the hole with mud on it's way out. Suspect the wasps don't differentiate between 737-800's and BN2A's.

[ExSp33db1rd]

Forgive me for being naive ? but the last Boeing I flew had an INS readout that showed groundspeed, so if the ASI failed couldn't just one apply the forecast windspeed, apply reasonable power settings, ignore the altitude, tho' advising ATC that one might not be maintiining one's clearance, look out of the window and return to base, tune up the ILS and complete a landing ? Or has "progress" overtaken such simplicity ?

( back to the cave ! )