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-   -   Indonesian aircraft missing off Jakarta (https://www.pprune.org/rumours-news/614857-indonesian-aircraft-missing-off-jakarta.html)

DaveReidUK 6th Nov 2018 21:58


Originally Posted by Mad (Flt) Scientist (Post 10303609)
Has it been definitively stated that is was the three immediately preceding flights? if it were intermittent over a longer period that's even more insidious.

From USA Today:

"The “black box” data recorder from a crashed Lion Air jet shows its airspeed indicator malfunctioned on its last four flights, investigators said Monday, just hours after distraught relatives of victims confronted the airline’s co-founder at a meeting organized by officials.

National Transportation Safety Committee chairman Soerjanto Tjahjono said the problem was similar on each of the four flights, including the fatal flight on Oct. 29 in which the plane plunged into the Java Sea minutes after taking off from Jakarta, killing all 189 people on board."

The last four flights were:

Denpasar-Manado 27 Oct
Manado-Denpasar 28 Oct
Denpasar-Jakarta 28 Oct
Jakarta-Pangkal Pinang 29 Oct

Lion Air jet's airspeed indicator malfunctioned on 4 flights

M68 6th Nov 2018 22:47


Originally Posted by DaveReidUK (Post 10303494)
One would have thought/hoped so.

But then again, one would have thought/hoped that the engineering response to a warning of a discrepancy between the inputs (either pitot or hydraulic) to the Elevator Feel Computer would have been to investigate those inputs, rather than just cleaning an electrical connector on an 11-week-old aircraft (!) and then confirming that there was no fault in the EFC itself, before signing off the aircraft as fit for flight.

For such a new aircraft (that, I guess, must be under some kind of warranty) is there actually an exchange of maintenance information happening between the airline and Boeing in a (real-)timely manner?
Or does Boeing usually not get to know what problems have occurred and (hopefully) been fixed by the airline's staff, even if it's a recently delivered airplane?

glad rag 7th Nov 2018 00:00


Originally Posted by Organfreak (Post 10303852)
If this information is verified, then the obvious conclusion is that there was some sort of malfeasance/misfeasance on the part of maintenance people.

And what if they had diligently followed the appropriate manufacturer advice and maintenance procedure[s] after each event? And had been unable to reproduce the fault?

I would suggest the firing of the company maintenance manager may be your biggest clue here at present.

"The plane shouldn't have been flying at all." Where is the mel listing for the max btw?

jolihokistix 7th Nov 2018 00:16

Re: Interesting examples of other similar events, and re: further comments on those but not on the main subject.

Please head with RE:

A Squared's comment above, "Ahhh, OK, obviously I though you were speaking of the current LionAir accident." hits a nerve and prompts me to post this reminder. Often during the course of this thread I see that when comments are made about a separate accident, bringing in little details such as V1, V2 called or not, it confuses the picture for everyone if no immediate indication is given first regarding which scenario they are describing.

In order to avoid non-signposted sidetracks and subsequent confusion.
Not a rule per se, but more manners or common sense?

Loose rivets 7th Nov 2018 00:25

hear hear. Warping into a different universe mid-puzzle tests even the greatest minds.

QDMQDMQDM 7th Nov 2018 01:32

Bloomberg reporting Boeing on the verge of issuing a safety alert on the 737 Max series:

https://www.bloomberg.com/news/artic...itter-business

Organfreak 7th Nov 2018 01:47


Originally Posted by glad rag (Post 10303916)
Where is the mel listing for the max btw?

http://fsims.faa.gov/wdocs/mmel/b-737-8_rev%200.pdf

Lord Farringdon 7th Nov 2018 01:49


Originally Posted by Loose rivets (Post 10303929)
hear hear. Warping into a different universe mid-puzzle tests even the greatest minds.

Which rather sounds like what those poor sods on JT610 were up against.

kristofera 7th Nov 2018 02:23


Originally Posted by QDMQDMQDM (Post 10303967)
Bloomberg reporting Boeing on the verge of issuing a safety alert on the 737 Max series:

https://www.bloomberg.com/news/artic...itter-business

The second to last sentence in that article is the best bit... "It wasn’t immediately clear if the airspeed issue had any connection with the angle-of-attack matter."

CONSO 7th Nov 2018 03:12

https://www.wsj.com/articles/boeing-...d=hp_lead_pos3


By
Andy Pasztor
Nov. 6, 2018 10:45 p.m. ET Responding to the Lion Air jetliner crash that killed 189 people in Indonesia last week, manufacturer Boeing Co. BA 1.24% and U.S. aviation regulators intend to issue twin safety warnings about potentially suspect flight-control software that can confuse pilots and lead to a steep descent of the affected aircraft model, according to people familiar with the matter.The moves are the first public indication that investigators suspect a possible software glitch or misinterpretation by pilots—related to an essential system that measures how high or low a plane’s nose is pointed—may have played an important part in the sequence of events that caused the Boeing 737 Max 8 to plunge into the Java Sea.

Goes on

Zeffy 7th Nov 2018 04:36

STS?
 
https://www.seattletimes.com/business/boeing-aerospace/boeing-to-warn-737-max-operators-of-a-potential-instrument-failure-that-could-cause-the-jet-to-nose-dive/
​​​​​​

...Pilots are typically trained on how to handle a “runaway trim” situation, said the person briefed on the Boeing bulletin, but that’s with everything else working as it should. In this case, the control column shaking, the stall warning, and the air speed indicator disagreement all combine to create confusion and keep the pilots very busy.

Boeing instructs pilots in the bulletin that if this failure arises, “higher control forces may be needed to overcome any nose-down stabilizer trim.” The instructions go on to say that after stabilization, the automatic trim system on the horizontal tail should be switched off and any trim performed manually...

aeromech3 7th Nov 2018 04:45

RE:

Originally Posted by M68 (Post 10303864)
For such a new aircraft (that, I guess, must be under some kind of warranty) is there actually an exchange of maintenance information happening between the airline and Boeing in a (real-)timely manner?
Or does Boeing usually not get to know what problems have occurred and (hopefully) been fixed by the airline's staff, even if it's a recently delivered airplane?

I worked in a Middle Eastern airline which had only 2 score aircraft but started a Defect Control Dept in late 1970's; each departure station would SITA telex the defects to base and these would be reviewed by a senior engineer and advice to Maintenance, they were also loaded into a very basic ATA program which would show on a measles chart repeat entries for investigation (the most frequent being ATA38, bogs basins). Each morning the Boeing and Pratt & Whitney rep would take note of the problems 1st hand from the hand written cardex system; when we joined up with an American Operator, we had a live link through dedicated SITA line to their Maintenance system; when ETOPS arrived this department was further tuned. With LION Air having over 100 Boeing's one would hope they have a monitoring Dept; it is likely that whilst the days of most resident Reps have gone by way of the bean counters exit route, there is now both ACARS and internet and surely manufacturers have similar access to relevant data from such a major airlines but then can only act bi laterally not instantaneously.

spongenotbob 7th Nov 2018 04:51

https://theaircurrent.com/aviation-s...ion-air-crash/

Wow...

Rated De 7th Nov 2018 05:25


Originally Posted by spongenotbob (Post 10304033)

That is staggering.
With the weather as observed, daylight and a known history it was difficult to imagine any pilot losing control to the degree that has been surmised.
That a transport category aircraft can enter an 'aggressive dive' that that upon release of the electric trim may commence again ought be a little more than a 'service bulletin'. Given the article references 'only during manual flight', can this trim hard over happen on approach, as a poor soul hand flies an ILS?

double_barrel 7th Nov 2018 05:46


The repeated uncommanded nose down action can be stopped by deactivating the stabilizer trim system, according to the official. Boeing warns that the stabilizer system can reach its full downward position if not counteracted by pilot trimming the aircraft and disconnecting the stabilizer trim system.
(my underlining)

Does that mean pulling a breaker?
Upon which trim will return to neutral? Or stay wherever it happened to be?

Eutychus 7th Nov 2018 05:53


Originally Posted by Rated De (Post 10304040)
Given the article references 'only during manual flight', can this trim hard over happen on approach, as a poor soul hand flies an ILS?

SLF question: so "fly the damn airplane", oft-repeated above, would in this case be the worst possible advice (and was most likely what the luckless crew were trying to do)?

Rated De 7th Nov 2018 06:03


Originally Posted by Eutychus (Post 10304052)
SLF question: so "fly the damn airplane", oft-repeated above, would in this case be the worst possible advice (and was most likely what the luckless crew were trying to do)?

Yes that was the point.
Following the checklist with the cacophony of noise alerts and aural tones, the luckless souls were supposed to ignore all the noise, and NOT fly manually.
If what is contained in the article is correct, this is beyond a service bulletin and requires an immediate cessation of operations and grounding until the root source of the fault is identified, isolated and rectified.
Give the often repeated mantra of 'commercial viability' the regulatory authorities would appear (again if this article is correct) to be quite happy to throw the luckless pilots flying this junk under the oncoming bus.
It reeks of regulatory capture, with the usual caveat of waiting for the service bulletin to be promulgated.

Eutychus 7th Nov 2018 06:18


Originally Posted by Rated De (Post 10304056)
If what is contained in the article is correct, this is beyond a service bulletin and requires an immediate cessation of operations and grounding until the root source of the fault is identified, isolated and rectified.

It certainly doesn't encourage me to get on a 737 MAX for the time being.

Capn Bloggs 7th Nov 2018 06:39


Following the checklist with the cacophony of noise alerts and aural tones, the luckless souls were supposed to ignore all the noise, and NOT fly manually.
If what is contained in the article is correct, this is beyond a service bulletin and requires an immediate cessation of operations and grounding until the root source of the fault is identified, isolated and rectified.
Give the often repeated mantra of 'commercial viability' the regulatory authorities would appear (again if this article is correct) to be quite happy to throw the luckless pilots flying this junk under the oncoming bus.
The QF A330 that took the plunge, twice, didn't result in grounding the fleet, despite the authorities NEVER working out what happened. Airbus came up with a procedure where crews push-button-disabled a particular system.


SLF question: so "fly the damn airplane", oft-repeated above, would in this case be the worst possible advice (and was most likely what the luckless crew were trying to do)?
If you're comfortable handflying and the aeroplane starts doing something in pitch you don't like with, say, full back stick, you trim against it. Or you grab the trim wheel and stop it. Or you engage the AP! My point is, you have to be happy with hand-flying to be able to have spare brain space to try something.

So, is the STS the culprit when the speeds/AoA go haywire?

A Squared 7th Nov 2018 06:51

From the Seattle Times article

In reference to the faulty AoA data ...


At the same time, it causes an indicator of the minimum speed to tell the pilot that the plane is near a stall, which also causes the pilot’s control column to shake as a warning. And the air-speed indicators on both sides of the flight deck disagree.
Does that mean that it causes the airspeed indicators disagree with each other, or does that mean that the airspeed indicators disagree with the stall warning/stick shaker (but agree with each other) ?


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