737-500 missing in Indonesia
 

737-500 Missing in Indonesia as per Flight Radar No information about carrier and other details

It’s Sriwijaya Air flight SJ182 as per FR24. Climbed to about 11000 feet and then entered a steep descent 😔

https://cimg6.ibsrv.net/gimg/pprune....c2a35fb7e.jpeg
https://cimg1.ibsrv.net/gimg/pprune....75de2e3337.png

To the uninformed Illiterate media who have no idea when it comes to Aviation, here’s a tip, look past the MAX, spend more time looking into how Air Asia Indo went down and you will find many similarities, weather including. Having flown in this part of the world many years ago I can assure you nothing has really changed. It’s still the same backwater with bull**** compliance to any form of internal check and training procedures.

It is still a member of the 737 family. That is all that matters in some eyes. An aircraft that we will be reminded goes back to 1969.

Debris found ...

https://www.mirror.co.uk/news/world-...plane-23289266

Seeing local reports that 59 passengers and 6 crew were onboard

https://pbs.twimg.com/media/ErSR6Q6W...g&name=900x900

Ok. Small debris field so we know the aircraft entered the water in one piece.

From 10000 to impact in less than 60 secs.
Something sudden must have happened to put the aircraft into such a dive.

Wx in the area from photos and radar looks ok.

Latest METAR
WIII 091100Z VRB04KT 6000 BKN022 25/24 Q1007 RERA NOSIG

Pilot suicide?
Stall? Spin?

I'm wondering if this was a bomb. It lost 5000ft in about 30 seconds whilst reducing speed.

Averege ROD from FL110 was 30,000+ fpm.

Could not yet find a good wx radar picture but apparently overcast with embedded CB-s.
Relevant metars:
WIII 090730Z 30006KT 5000 -RA FEW017CB OVC018 25/24 Q1006 NOSIG
WIII 090700Z 30007KT 4000 VCTS RA FEW016CB OVC018 25/24 Q1007 NOSIG
WIII 090630Z 34007KT 2000 TSRA FEW016CB OVC018 25/24 Q1007 NOSIG RMK CB OVER THE FIELD

Speed shown by FR24 is horizontal groundspeed, not TAS

It appears from the FR24 yellow curve that the speed spiked at 360kts while close to sea level, doesn't it?

No significant convective activity visible in the 07:40 UTC high res satellite imagery.

https://cimg9.ibsrv.net/gimg/pprune....f8f0736e5b.jpg
Channel B13 cloud top temperatures (coloured < 41C)
https://cimg9.ibsrv.net/gimg/pprune....3c997e9cd4.jpg
true colour visible image.

If the aeroplane descended that fast into a small area it was unlikely to be a bomb. Bombs tend to precipitate aerodynamic breakup of a structure that is travelling at speed and consequently debris is scattered over a wide area. To achieve a 30,000 ft/min descent the aircraft has to be aerodynamically intact and pointing vertically downwards. Loss of part of the empennage, human input or simple loss of control are just a few causes consistent with such a terminal descent.

The G/S prior to departure from the intended path was ~290kts suggesting a stall or spin to be very unlikely. Speed appears to have exceeded 360 kts in descent. From the AVH local fisherman's reports suggest it was raining in the crash area and Jakarta reported CB activity around the time. It is possible that an unintended entry into a thunderstorm may have caused loss of control. The cynic in me says lack of regulatory oversight in this region will also be a factor..... yet again.

Good to see all you armchair experts have put your COVID epidemiology second guessing on hold for a moment and gone back to what you really “know” i.e. accident investigation via flightradar data. :D

Crew and passenger names are already in the public domain, unfortunately.

Loss of control
 

Hope that we get a decent accident report. Indonesia is not known to be very active on those. That airliners fall out of the sky in such a way is unusual. That looks like a severe control problem, so there should be a high interest to find the root cause. Any idea how deep the water is there?

Testing times
 

How will Boeing play this. Blame the crew, the operator, the country, or just wait and see.

Boeing / NTSB should be accredited representatives in an investigation. Technically sound, but media management could be a challenge, testing whatever Boeing has learnt or not in this area, and in relation to the Max.
P.S
Or what Ppruners have learnt or not about speculative comments.

Too soon to know, of course, but prime suspects are violent interaction with a CB cell causing structural failure, or pilot suicide. The latter is generally a taboo subject, but has occurred with sad regularity over the past 30 years.

Having flown Hajj ops to and from Indonesia over some years, I can verify from experience that adverse weather situations can be vicious and fast-forming. ATC have no weather radar to assist, as with most parts of the world outside North America.

Hopefully the FDR and CVR can be recovered and can be interrogated successfully. Another sad day for aviation. Condolences to those involved.

So it lost 7875 feet in 11 seconds-jeez.
Has to be vertical, and surely largely intact to achieve that ROD.

EDLB
"Debris and body parts were located in waters of about 15 meters depth near Lancang Island."

AvHerald

Pilot suicide? If the pilot put it into a dive, we'd see a big increase in speed as the altitude decreased.
Stall? Spin? If that were the case, we'd see the speed getting dangerously low before the altitude drop and even then, it should be recoverable from that altitude. That drop in altitude would give more than enough speed to recover from a stall.

Instead the altitude and speed both suddenly dropped at the same time, which seems to indicate a sudden structural failure of the aircraft.

56 pax and 6 crew = 62 souls.

The airline's website is very basic and still fails to mention the accident or any support for families and friends of the pax and crew.

Peter, fair points. Stall can be achieved irrelevant of airspeed though. All down to AOA. Stall a 737 at 250kts no doubt. But yeah evidence is pointing toward something giving way and the aircraft nose diving into the sea below.

Sriwijaya Air eyes resumption of full operations after securing maintenance services from Garuda

We may well see that on the FDR readout.

Groundspeed
 

No, again: FR24 shows "groundspeed", not IAS. When the aircraft points downwards, groundspeed automatically drops. A 90° vertical dive downwards means "groundspeed 0kts". Nothing indicates a midflight break-up. In contrary: it kept sending ADS-B data including GPS position.

yep, data were transmitted to the impact. They had at least electrics intact, and most likely engine power due to ROD, so midair breakup unlikely.

Boeing 737-300 Silkair MI185 had a similar descent profile when it went in in 1997. See: https://en.wikipedia.org/wiki/SilkAir_Flight_185

A lack of recency doesn't cause a nose dive passing FL100.

PK-CLC flight profile
 

FR24 ADS-B data
Timestamp Alt GS HDG
07:39:56Z 10800;287;42
07:40:02Z 10900;287;30
07:40:05Z 10900;287;23
07:40:08Z 10725;287;6
07:40:14Z 8950;224;339
07:40:16Z 8125;192;338
07:40:20Z 5400;115;11
07:40:27Z 250;358;93

That's not the case when looking closely at the FR24 data. The aircraft remained on a stable northern course throughout the entire steep descent. It's just the very last ADS-B data point which suddenly "jumps" kilometers to the East. That's what causes the odd 90°-to-the-right track in FR24 display. And this also caused the spike in groundspeed at the very end.

It's obviously a false data point, maybe caused by an incomplete/corrupted ADS-B transmission.

Maybe.

Though the final few points are also consistent with a spiral during the last seconds of the trajectory - provided one resists the temptation to use straight lines to join the dots and infer instantaneous 90° turns ...

The profile looks similar to Air Sweden 294. In that case, instrument failure and spacial disorientation caused them to loose 21000 feet in one minute.

Could you please refrain from continuing mentioning pilot suicide in here. you absolutely zero evidence for that so out of respect for the families of the victims and the pilots , turn it off. We have seen how repeating a falsehood long enough on internet can turn mobs into believing it.
Nobody has any, zero evidence to what happened a few hours ago.

There are not that many options IMO:
- suicide
- Somatogravic Illusion / disorientation (but the would have seen the ground, the weather doesn't seem that bad, does it?)
- some kind of H stab failure/jam
- some kind of trimming issue, misconfigured AP or siilar?

In any case, it's getting strange how Boeings are nosediving from the sky:
- Fly dubai - Atlas - and now this

Has there been something similar with fatal consequences involving an Airbus? Apart from Germanwings, which was (supposedly) suicide, but even that one didn't really nosedive.

not appropriate in a proffesionals forum
 

andrasz, #33

You perpetuate the mistake which the FAA made in concluding that whilst a 3 person crew identified a fault, then a 2 person crew in similar circumstances would act and be capable of achieving a safe outcome.

Your views on this accident re maintenance, CB, LOC, IMC are ill founded - no evidence or reasoned argument in comparison with others experiences.

Bias, inappropriate cause and effect; not appropriate in a professional forum

Yes:
Gulf Air 072: A disorientated pilot dived into the sea with forward pressure on the side stick.
Air France 447: A disorientated pilot maintained back pressure on the stick until a stalled aircraft crashed into the sea.

In both these incidents having the two sticks physically connected together could have prevented both of these.

They lost 10000 feet in 19 seconds. That is no spin, more a direct nose dive. If it was not deliberate my bets are, that something on the tail got wrong.

F-MANU

If this data is correct, then according to the ground speed this aircraft went from a cruise-climb at 287 kts to a descent (less horizontal speed, altitude reducing), and then finally to a ground speed of 358 kts, i.e. it had resumed horizontal travel.

An emergency descent, for whatever reason, maybe got too fast in the descent and/or then pulled out too late, almost made it, but hit the sea?

The left turn seen in the HDG data; possibly yaw caused by a No 1 engine failure?