Its not an extract of the AF447 report but the AF447 accident is listed as the classic example of loss of control where the crew should have been able to handle the problem. I am not sure which incident the extract refers to. Its never too early to speculate but probably it is too early to have any factual information.

My apologies for any confusion, the extract referred to another B737 accident (Adam Air) & was not meant to imply AF447. I was just trying to make the point that occasionally accidents occur for reasons that seem hard to fathom...

Does anyone know if this particular 737 would have the older FDR that only recorded 4 parameters or the later model that recorded more (200 I think)?

fdr

Thankfully uncontained failures are rare, If it does occur however despite designing to keep critical systems and components outside the burst zone the final outcome is heavily dependant on chance. This is far beyond any certification case and a disc failure can break the engine in 2 which is likely to result in detachment of the fan cowl doors and possibly the reverser C ducts. The front and rear of the engine could still be attached to the airframe but significant damage to the pylon could have occurred. An instantaneous loss of thrust coupled with a drag increase as the nacelle breaks up is possible. Occurring at high rating on climb out would be very hazardous.

Lookleft

No first hand knowledge, but my educated guess is that - based on when it would have been built - it had a higher tech Digital FDR with lots of parameters (the new ones have thousands of parameters).
I'm more concerned with the health of the FDR - it's not exactly unheard of that the FDR isn't working properly at the time of a crash. Checking the proper functions of the FDR (and voice recorders) is not a high priority for the maintenance types, even in the west.

Lookleft

"Another FAA rule change that took effect October 11, 1991, led to the installation of digital FDAUs (DFDAUs) and DFDRs with solid-state memory on all Boeing airplanes before delivery. This FDR system was required to record a minimum of 34 parameter groups. The DFDAU processes approximately 100 different sensor signals per second for transmission to the DFDR, which uses electronics to accommodate data for a 25-hr period."

s01

The accident aircraft was built in 1994.

Sorry for being a bit facetious, but it's not about priorities - each airline worth their weight in salt will be following guidance from the OEM manufacturer planning document and approved by their national authority in their maintenance programme. Priorities don't come into it.

BBC reporting black box locator isn't working - new one on it's way from Singapore

https://www.bbc.com/news/world-asia-55628294

Dannyboy39

They shouldn't but even in proper First world airlines they do I'm afraid - you can't expect a LCC with a 30 minute turnround to get the same TLC as one that takes 90 minutes on the ground :(

The purpose of the CVR or the FDR is not to download it after every flight and there is no maintenance requirement to do so. There is also a mandate coming with requires 24 hour recording, not just 2 hours. The systems get periodically function tested and the ULBs get replaced every 5-6 years too.

FDR and CVR and both MEL approved items, so the point is moot.

the box is found!

Apparently the FDR, not yet the CVR.

Short haul airliners whether on the ground for 30 mins or 90 mins receive no TLC during a turnround other than a walk round conducted by the flight crew or sometimes an engineer. In EASA land there is a brief engineering check every couple of days but between that the aircraft could fly 10-15 sectors without ever being looked at by an engineer.

^^ To be precise, every 48h an engineer checks the aircraft.

tdracer

Flightcrews at my airline preflighted the CVR on the first leg of the day. I don't know about maintenance with the FDR.

DaveReidUK

The minimum 34 parameter groups:

1. Time or Relative Time Counts
2. Pressure Altitude
3. Indicated airspeed or Calibrated airspeed
4. Heading (Primary flight crew reference)
5. Normal Acceleration (Vertical)
6. Pitch Attitude
7. Roll Attitude
8. Manual Radio Transmitter Keying or CVR/DFDR synchronization reference
9. Thrust/Power on each engine—primary flight crew reference
10. Autopilot Engagement
11. Longitudinal Acceleration
12a. Pitch control(s) position (nonfly-by-wire systems)
12b. Pitch control(s) position (fly-by-wire systems)
13a. Lateral control position(s) (nonfly-by-wire)
13b. Lateral control position(s) (fly-by-wire)
14a. Yaw control position(s) (nonfly-by-wire)
14b. Yaw control position(s) (fly-by-wire)
15. Pitch control surface(s) position
16. Lateral control surface(s) position
17. Yaw control surface(s) position
18. Lateral Acceleration
19. Pitch Trim Surface Position
20. Trailing Edge Flap or Cockpit Control Selection
21. Leading Edge Flap or Cockpit Control Selection
22. Each Thrust reverser Position (or equivalent for propeller airplane)
23. Ground Spoiler Position or Speed Brake Selection
24. Outside Air Temperature or Total Air Temperature
25. Autopilot/Autothrottle/AFCS Mode and Engagement Status
26. Radio Altitude
27. Localizer Deviation, MLS Azimuth, or GPS Lateral Deviation
28. Glideslope Deviation, MLS Elevation, or GPS Vertical Deviation
29. Marker Beacon Passage
30. Master Warning
31. Air/ground sensor (primary airplane system reference nose or main gear)
32. Angle of Attack (If measured directly)
33. Hydraulic Pressure Low, Each System
34. Groundspeed

Would pilot knowledge of the existence of recording of parameters nos. 27 & 28 tend to reduce enthusiasm for hand flying approaches? Would it be outside the realm of practicality for airline management (e.g. chief pilot) to occasionally randomly review such data?

Most modern airlines already do this... Flight Data Monitoring (FDM). And it's not random, everything is monitored for 'trends'. But that's another discussion altogether

Blake.Waterman

27y/o airframe or not. Ripped of Vertical stabilizer is an extremely rare occurrence and more importantly will in all likelyhood lead to a much less stable terminal flight profile. Whatever accuracy we assume for FR24 data the speeds/altitudes indicate rather clearly an aircraft that went in nose first. Losing the V/S will very likely lead to much more erratic profiles/behahviour on the way down.
In any case the FDR will give clear indication about directional control on the way down and will thus answer this question relatively quickly.

Flight Global reporting return of accident aircraft from storage:
Crashed Sriwijaya 737 certified airworthy after nine-month storage: investigators | News | Flight Global

(Apologies if this was posted previously)
WR 6-3

Added: Wall Street Journal now reporting parallel information, with some quotations attributed to pertinent officials (and some consultants as well).

It's somewhat disconcerting that this is Sriwijaya's 5th 737 loss since 2008 according to Flight Global, and in early 2020 Indonesian media reports indicated that a "half of Sriwijaya’s fleet was grounded owing to a lack of spare parts".

The sheer amount of idle-born speculation on this thread reminds me of why I spend so little time here.
I checked in to check up if we had a FDR yet.
I suspect that most people on this thread have never had a seat in the cockpit. Your suppositions, wild imaginings and shameless posturing of your bombast is all utterly disgusting and in incredibly bad taste.
Lives have been lost. The reasons are yet unknown - and therefore neither Rumour or News.
If you are not industry related you have no right posting this dreck here. Isn't there somewhere else you can go online and post this nonsense? amongst your own kind, as it were.

FDR has been recovered and handed over to Transportation Indonesia authorities

https://cimg2.ibsrv.net/gimg/pprune....4561fc146c.jpg

unworry

Hard to tell for sure, given that the container is half full of water for no apparent reason, but it looks like one of the original AlliedSignal/Honeywell 980-4700 series. That would make it about the same vintage as the aircraft itself.

The reason to keep it under water is to keep parts from oxidizing.

Expanding slightly on the above answer;

Question: Why, after a plane has crashed into the water, do investigators put the "black box" back in water? – Will Cowger, Houston Answer: If a flight data recorder is recovered from the water, it is submerged in fresh, clean water to prevent deposits such as salt or minerals from drying out within the device.

When the technicians at the laboratory are ready to download the data, they take the recorder out of the freshwater bath, carefully open it and dry any sections that have been exposed to water. They then download the data into special computers that can read the information.

Think about the "Mary Rose" or the "Vasa" - they were kept in a wet environment for years after they were recovered

Why are FDRs and CVRs recovered from underwater transported to where they are analysed in water?

Aviation StackExchange: Why is the FDR and CVR put into water again after a water crash?

The article in the above link links to NTSB: Flight Data Recorder Handbook for Aviation Accident Investigations (PDF)

The NTSB Handbook in section 3.9 says:
This demonstrates that for the NTSB at least (and likely for other organisations), this is standard practice, even though the handbook does not detail why the procedure should be followed. There is plenty of uninformed comment on the Internet giving unreferenced opinions on why this procedure is followed. Most Internet search engines will allow you to find such opinions.

The salts in seawater form an elecrolyte that corrodes any exposed metal alloy (in practice all used metals, it is very rare to find any that is 100% pure), or even pure metals if there are different types in close proximity like PCB-s. This is a rather slow process, but if oxygen (air) is introduced, it speeds up dramatically, as fresh surfaces created by the electrolytic process are immediately oxidised, and the oxide film amplifies the electrolitc process. Any electronic equipment accidentally or otherwise immersed in seawater needs to be either rinsed thoroughly with distilled water immediately, or left in freshwater that protects it from air. Even leaving it immersed in salt water is better than exposing it to air. While the FDR memory chips (actually the whole memory module) is sealed in plastic and resin, the contacts and supporting circuitry will be corroded if this precaution is not taken, and readout will become much more complicated, requiring the disassembly of the memory module. Much easier and safer to keep it immersed, and have it cleaned and dried in the lab.

Which part you don't understand ? In the overwhelming majority of LOC incidents, faced with a spinning altimeter the pilots are far too busy trying to figure out what is happening and how to save themselves (and all those behind them) than to waste precious time on a radio call of no immediate benefit.

andrasz

Quite so.

Elapsed time from the initial divergence from the departure track, until impact with the Java Sea: 33 seconds

Doesn't the FAA say that any pilot can diagnose the problem in 4 secs. and apply corrective measures?

Applying corrective measures may not be the problem, responsive corrective measures may be the issue.

At Lockerbie, the pilots probably knew they had a sudden decompression, but no matter what corrective action they took, it was out of their hands.

andrasz

Absolutely agreed. At best, it would be a conscious (and correct) decision to prioritise 'aviate' over 'communicate'. Alternatively it could be that the crew became dumbstruck. The power of coherent speech, especially on the radio, quickly declines when adrenaline surges in a survival situation. The ability to listen goes early as well. Visual comprehension survives longest as stress levels increase, so at least Mother Nature has wired our brains in a way that suits the priorities of emergency handling!

andrasz, Having been in a nasty incident myself many years ago, I fully agree. Even on a three crew aircraft, all three of us were totally occupied with no time for a radio call until much later.

Interesting. Indonesian Plane Went From No Flights to 132 in Less Than a Month The mothballing adds another possible factor in the crash of the 26-year-old Boeing 737-500, which killed 62 people on Sriwijaya Air Flight 182.

https://www.nytimes.com/2021/01/13/w...gtype=Homepage

Doesn't look good for finding the CVR. There are 2 pingers on top of that box and a torn up chunk of recorder box.

foxcharliep2

Once again the medias filling the gaps...PK-CLC resumed service on the 20th December following a 9 month storage, then it flew 5-6 legs a day which is fairly consistent with a short-haul regional airline...