FZL at FL150...?

@ vanHorck When at altitude there is a windspeed of say 70 knots and you turn into the wind, your groundspeed (ADS-B) will drop but the airspeed remains the same.

Owen61

Nothing, because the -500 engines are still under the wing, not in front of it.

The 737-500 does have a pitch power couple, but it's controllable... Hence it's just part of the characteristics of the aircraft that you get to know quite quickly when you operate it...

I found it interesting that a -500 had winglets...

This model would have had pickle forks...

It has STS operating from 100 kts to 300 kts with flaps UP but it's easy to override. The thrust rating for the -500 is also limited to 20k if I remember correctly. 22k is not available for this model.

I think airBaltic in Europe was the last to fly this model, rated at 18k.

For you to compare the "deep dive and attempt to recover" theory, I plotted the Atlas Air final 30 seconds, from precise FDR data, now with pitch, aircraft-calculated Groundspeed and airspeed.
Both pilots applied full elev noseup from 12:38:57 on
Note Groundspeed increasing again with delay, flattened ALT drop began with Pitch -30°

https://cimg5.ibsrv.net/gimg/pprune....5d5a9b3df0.jpg

I got confused with the A318, which does have a different tail. In that case it will have a reduced directional stability vs the other members of the family... Maybe a yaw damper gone haywire?

I find this comment and ATC Watcher’s earlier post rebuking someone for mentioning suicide quite interesting in terms of the intersection of culture and safety. Westerners on here are always quick to highlight adverse impacts of other cultures’ social norms on safety, and are quick to criticise when foreign investigations steer clear of taboo subjects. Typical examples might be absolute deference to authority, the need for those who’ve erred to save face, and avoidance of any criticism of the national government, its airline or its regulator. All are grist for the mill on here every time an Asian carrier suffers an accident.

Now let’s turn the lens back on ourselves. Suicide is probably the only Western social taboo which intersects with safety. Does that mean it should not be postulated or discussed? None of us would argue that the ‘Asian’ taboos should stay off limits where safety is concerned; why should our taboos be treated differently? That would be exceptionalism. So I say that discussion of suicide is fair game in a safety and accident prevention context.

To ATC Watcher and others who would argue that discussing it is in poor taste, I would say firstly that in recent years there have been enough confirmed or officially-postulated cases that any lay person posting on Facebook could readily come up with the theory themselves and bring scrutiny on the families; it’s not as if us ignoring the subject would prevent that. And I would point also to the statement by the captain’s family; I’m sorry RTM Boy, there is evidence (albeit only a scrap) posted in the thread above. Hopefully you missed that and are not wilfully ignoring it, although such would be the power of a taboo. (Edit: the link has vanished up-thread so I'm reposting it here).

Of course I hope that it is not the cause of this accident, but it makes no sense to discard the possibility at this point. Anyone know if this carrier has a ‘rule of two’ or whether the subject has been considered by any Asian regulators besides the Japanese?

Interesting article of that happening on a -200: https://flightsafety.org/ap/ap_may98.pdf

When will the remote discussion about the weather factor and CB ever stop? The plane never flew into the heavy stuff.

And this is the temperature at 10000 ft at the place these days. No, if you have this, there would be no freezing in a CB at the same altitude either.

Temperature Jakarta at 10000 ft

Please guess somewhere else.

Easy street : You completely missed the point. Do not come up with cultural differences with me , I worked in a multinational/multicultural environment for 35 years . But I will no go there , My point is that people here make allegations and suppositions based on absolutely nothing , just to write something on internet . But this is not Facebook or Twitter , this is a Profession forum where lots of non-aviation educated people are looking for immediate answers to an accident . What is written here is often quoted by the press , and we do not need " a professional pilots group mentioned suicide ." , if picked up by local news can have a devastating effect of the families looking for answers.. We have seen this before and it can turn ugly..
As to your question about the rule of 2, how is this relevant ? 4 minutes after take off passing 10.000 ft ?

It’s not based on ‘absolutely nothing’. The flight profile is arguably a good enough reason to make the suggestion, but the captain’s family’s own statement to the media is unequivocally a good enough reason to make it. And also to render your concern for their privacy and the mental well-being of the passengers’ families somewhat irrelevant at this point.

As for the ‘rule of two’... would a FO be concerned about an instruction from the captain to leave the flight deck shortly after seatbelts off? Or might the whole subject of pilot suicide be so taboo that they would think nothing of it?

People, even pilots, have been known to be taken short with dramatically minimal notice. Rule of two is surely not irrelevant.

4 minutes after take- off?

Stall at 280kts? in a 737 with 56 Pax on a one hour flight?
It was around 15:00 local time !?

Easy Street

I think you may be reading too much into the western/eastern taboo stuff. I'm a researcher and investigator. It's my job to ask questions, to find answers, to be objective and analytical. It's also my job not to jump to conclusions (tempting though it is and interesting as theorizing is). Evidence, sound, solid evidence is required. From an investigation perspective it's folly to theorize and try to have evidence fit the theory. At this stage (I think my preface in my OP made that clear) we have no solid evidence for a suicide theory. That does not dismiss the possibility, but it would be entirely wrong to jump to the conclusion that this is the cause based on nothing much, which some have done.

Whatever happened happened just 4 minutes into the flight, still climbing, when both pilots must have been in the cockpit (who knows of a pilot leaving the cockpit at this point?). The suicidal pilot would either need to be on their own (highly unlikely 4 minutes into the flight unless the other pilot got a sudden attack of the runs) or have incapacitated the other pilot (how when presumably the crew will have passed through security meaning knives or guns should have been picked up - even at Jakarta?), or both pilots would need to be in cahoots (really???). If the incident had occurred at cruising altitude, when the other pilot might have left the cockpit, the probability might be somewhat higher.

If you do want to put a probability percentage on suicide at the cause, given what we know so far, it wouldn't score very highly. Not because it's "taboo", but because other possible causes, given the circumstances, are more likely.

But this is all theorizing atm. We won't have to wait too long for the CVR and FDR to hopefully provide all the answers.

Boeing is aware of media reports

CHICAGO, Jan. 9, 2021— Boeing today released the following statement:

“We are aware of media reports from Jakarta regarding Sriwijaya Air flight SJ-182. Our thoughts are with the crew, passengers, and their families. We are in contact with our airline customer and stand ready to support them during this difficult time.”

Question, I read the flight was scheduled to be operated by an -800 and the -500 was a last minute swap in. Would the same crew operate both? Are there significant enough differences between the two for that to cause issues?

It's the same type rating with adequate difference training.