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

wheels_down 29th Oct 2018 08:48


Originally Posted by EIFFS (Post 10295401)
Im not surprised the Australian government have issued a no fly for staff & contractors, did they not ground Lion air some years back when ex bmi flight management became the fall guys.

That was Tiger (now a Virgin Australia subsidiary)

Lion never started an Aussie Domestic operation however they did lodge. They pulled out because of high expected costs.

chillpill 29th Oct 2018 08:59

Every time there is an incident/accident, this place is bombarded with posts made by 'instant experts' based upon ADS-B data and tenuous links to previous events.

There is nothing professional about this. Nothing. It's also wholly disrespectful to those who have been tragically effected by these sad events.

I just wish we could leave this to the experts from the relevant countries safety authorities, accident investigation departments and other relevant stake-holders who are highly trained in such investigations and who are also motivated to get the answers as to 'why' as soon as practicable.

I know this is an open 'forum' but perhaps the moderators might consider some filtering to at least retain professionalism, facts and accuracy from posts made on PPRUNE, rather than drivel and conjecture, when we are faced with tragic events such as today.

RIP to all those lost.

IFixPlanes 29th Oct 2018 08:59

I dont get it.
You have 3 independent sources for speed and hight. If you have different indications then compare the 3 values. When the CAPT indication is different to IFSD (integrated standby flight display) and FO indication and these two are equal then switch indication and NAV on 2 (FO) and have a good flight.

A Squared 29th Oct 2018 09:03


Originally Posted by Maisk Rotum (Post 10295415)
And I say again there is absolutely no excuse for taking the lives of 189 people because the crew could not correctly execute the unreliable airspeed memory items.


It's a bit early to state with confidence that the accident resulted from A: Unreliable airspeed indications, and B: specifically, the crew's failure correctly execute said procedures.

Dct_Mopas 29th Oct 2018 09:26


Originally Posted by IFixPlanes (Post 10295425)
I dont get it.
You have 3 independent sources for speed and hight. If you have different indications then compare the 3 values. When the CAPT indication is different to IFSD (integrated standby flight display) and FO indication and these two are equal then switch indication and NAV on 2 (FO) and have a good flight.

Nope.

So if those two indications match at 20 knots youre going to switch and use them?

You level off using pitch power datums, assess which readout is correct (maybe two are erroneous due impact damage with birds) then make a logical decision using all the information to hand. Methodically.

A Squared 29th Oct 2018 09:30


Originally Posted by chillpill (Post 10295424)
Every time there is an incident/accident, this place is bombarded with posts made by 'instant experts' based upon ADS-B data and tenuous links to previous events.

There is nothing professional about this. Nothing. It's also wholly disrespectful to those who have been tragically effected by these sad events.

I just wish we could leave this to the experts from the relevant countries safety authorities, accident investigation departments and other relevant stake-holders who are highly trained in such investigations and who are also motivated to get the answers as to 'why' as soon as practicable.

I know this is an open 'forum' but perhaps the moderators might consider some filtering to at least retain professionalism, facts and accuracy from posts made on PPRUNE, rather than drivel and conjecture, when we are faced with tragic events such as today.

RIP to all those lost.

There is nothing unprofessional or disrespectful about taking the facts that are known, and applying knowledge of aviation to consider how an accident may have occurred. This is not a news organization presenting speculation as fact. If is a forum. Forums are for discussion. We are discussing things.

StormyKnight 29th Oct 2018 09:43


Originally Posted by wiedehopf (Post 10295372)
Anyway the accident airplane was going a lot faster than a similar type at that altitude in the same conditions.

I agree, I wonder if this is the sort of speed you would reach if you were to put the throttles to the position they should go to as part of the checklist for an air speed indicator failure. We have had a lot of stalled aircraft in recent years, albeit at altitude, but my understanding is that there is a set throttle position & pitch that gives a reasonable guarantee that the plane will maintain altitude whilst diagnosis of the situation is performed assuming good working engines & flight surfaces.

ChiefT 29th Oct 2018 09:43

Guys, all ideas about the cause of the crash are pure speculation at the moment. Could be a fault in the engines, pivot tube covers, pilot faults or a big bird shitted into the engines.

We'll read it soon, latest in the accident report and personally I hope, that they'll learn about this accident. Lion Air and Indonesia in general showing a pretty poor safety record....

A Squared 29th Oct 2018 09:44


Originally Posted by Maisk Rotum (Post 10295462)
A little early you say when the aircraft had precisely had that happen on the previous flight? ???

Certainly unreliable airspeed indication is one possible cause whcih shouldn't be discounted. We are, however, a long way from being able to say that we *know* that this was the cause. Yes, the fact that the airplane was previously written up for unreliable airspeed is an important clue. But it is in no way proof positive that the problem repeated itself. If it were, accident investigation would be vastly simplified. We could just pull out the maintenance log, find the last problem reported, and list that as the cause of the accident.


To put it differently, it is one thing to speculate that unreliable airspeed may have been a factor, and that there is evidence whcih supports that speculation. It is something completely different to state as fact, as you have done, that we know that the passengers were killed by the incompetence of the crew. Sadly, I suspect that you may lack the intelligence and basic human decency to grasp that distinction.

vilas 29th Oct 2018 09:50

If it was UAS then crew competence comes in. It could be flight controls problem.

Volume 29th Oct 2018 10:11


A stall seems unlikely as they rather seemed to be going quite fast.
If airspeed is unreliable, it does not matter that it indicates the aircraft is going fast.
Unreliable might mean too hig, unreliable might mean too low, for sure unreliable means neither the pilot nor any speculations should rely on it...

Anyway, the aircraft took of around 90 Minutes after sunrise in good weather. Quite different from Birgenair or AF, there was clear visual reference all the time. Good pilots could handle aircraft under such conditions even after full loss of instruments...


It could be flight controls problem.
Is the 737 max full mechanical controls? Or are there some FBW elements in the control systen which require valid air data to work properly?

A Squared 29th Oct 2018 10:21


Originally Posted by Volume (Post 10295496)
If airspeed is unreliable, it does not matter that it indicates the aircraft is going fast.
Unreliable might mean too hig, unreliable might mean too low, for sure unreliable means neither the pilot nor any speculations should rely on it...

The "...seemed to be going quite fast" observation is a reference to the "Flight Radar24" data, whcih is ADS-B data, derived from GPS measurements and is completely independent of, and unaffected by any problem with airspeed indications.

If your GPS reported groundspeed is is approximately 300 knots, a stall is pretty unlikely.

Auxtank 29th Oct 2018 10:25

Two minutes in to the flight, 334 KTS at 1600 ft, I 'd be interested to know about flap retraction and whether something broke off leading to flight controls issue ongoing and unrecoverable.

sonicbum 29th Oct 2018 10:28


Originally Posted by Volume (Post 10295496)
Is the 737 max full mechanical controls? Or are there some FBW elements in the control systen which require valid air data to work properly?

Full mechanical.

groundbum 29th Oct 2018 10:45

did the accident crew know about the technical issues of the previous flight? I know they *should* know since it was written up, but we saw in the Air Canada SFO pre-flight briefing the crew totally missed vital information about the runway closure. Perhaps the same thing here, the accident crew omitted reading the tech writeup, or didn't take onboard the significance of it?

G

ManaAdaSystem 29th Oct 2018 10:48

This one is really staring you in the face. Airspeed problem previous flight. System flushed and tested OK on ground.
New flight, loss of control.
Not 100% sure, but I believe a test flight by one of our technical pilots would have been done before the aircraft was released to the line if this snag happened in my airline.

ManaAdaSystem 29th Oct 2018 10:50


Originally Posted by groundbum (Post 10295528)
did the accident crew know about the technical issues of the previous flight? I know they *should* know since it was written up, but we saw in the Air Canada SFO pre-flight briefing the crew totally missed vital information about the runway closure. Perhaps the same thing here, the accident crew omitted reading the tech writeup, or didn't take onboard the significance of it?

G

Not all pilots go through the previous write ups when they check the log.

Flutter speed 29th Oct 2018 10:50


Originally Posted by sonicbum (Post 10295512)
Full mechanical.

Except for the spoilers. see

Icarus2001 29th Oct 2018 10:54


A stall seems unlikely as they rather seemed to be going quite fast.

If your GPS reported groundspeed is is approximately 300 knots, a stall is pretty unlikely.
So at least two people above have no grasp of critical angle and what a stall actually is. :rolleyes:

sonicbum 29th Oct 2018 11:00


Originally Posted by Flutter speed (Post 10295534)
Except for the spoilers. see

Indeed, forgot to mention it. By the way, out of curiosity if someone has a MAX QRH handy, is there any reference to the operation of LAM in case of airspeed unreliable ?


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