Indonesian aircraft missing off Jakarta

[On2it]

Kompas TV is showing video of a large plastic bin coming aboard allegedly containing the flight recorder
There is also underwater scenes showing a large amount of shattered wreckage on the sea bed not unlike the pulverised A320 of germanwings
Why anyone thought a large wreck was likely is beyond me

[dinbangkok]

Originally Posted by Airbubba

A report that the 'black box' has been found:

https://www.straitstimes.com/asia/se...-boxes-in-java

Images on MetroTVNews (which incidentally shows rolling coverage of the entire operation: Streaming Video | Metrotvnews.com as it did for the Air Asia incident), has shown footage of the plastic transparent boxes used to transport the black boxes being loaded on to one of the search vessels (with the press scrambling round while some bloke placed one of the recorders into the box). We've also caught sight of some Western investigators who've just arrived, trawling through the assorted bits and pieces that have been brought to shore which I suspect based on yesterday's footage of people hanging off the side of boats fishing stuff out of the water, may well comprise extraneous junk picked up during the search. As is the case in this part of the world the media appear to have carte blanche to follow the teams everywhere (yesterday a gallant reporter was shown accompanying one of the divers deep under water to look for the black boxes). It is what it is though so it's a major relief that the recorders have been found. Here's hoping that someone remembers to record the co-ordinates of where at least some of the aircraft debris was found floating.

[ajamieson]

On the MAX, are the CVR and FDR housed in the same unit? The Indonesian transport ministry doesn't seem to know... they say they've found one but not the other.

[DaveReidUK]

Originally Posted by HundredPercentPlease

Has anyone suggested or said that it's "reasonable"?

Apologies, on re-reading the thread I see that the "reasonable expectation" (of being killed in a perfectly flyable aircraft) quote that was attributed to you wasn't something you actually said.

Originally Posted by edmundronald

HundredPercentPlease
You are saying that *by design* a single blocked orifice (pitot or static vent) can put the pilot's control systems in a state such that conventionnally trained and certified airplane pilots will quite reasonably be expected to lose control and terminate in an encounter with terrain at speed, even though control surfaces and engines are fully functional. As an engineer, I would call this a clear case of absence of redundancy, and cannot understand that such a design would obtain certification.

Originally Posted by HundredPercentPlease

No, I am not saying that.

Apologies again.

[pineteam]

Would be interesting to know if the crew were doing raw data flights in a regular basis as per Airbus test pilots recommendations. Does Lion Air allows their pilots to fly raw data? When do the airlines will undestand it can be the difference between life and death?

[CaptainSandL]

Originally Posted by MickG0105

Can somebody familiar with the Speed Trim System please comment on whether it would have been engaging and disengaging if the aircraft accelerated and decelerated through 300 KIAS. Thanks.

From the MAX FCOM 9.20.8:

Speed Trim System
The Speed Trim System (STS) is a speed stability augmentation system designed to improve flight
characteristics during operations with a low gross weight, aft center of gravity and high thrust
when the autopilot is not engaged. The purpose of the STS is to return the airplane to a trimmed
speed by commanding the stabilizer in a direction opposite the speed change. The STS monitors
inputs of stabilizer position, thrust lever position, airspeed and vertical speed and then trims
the stabilizer using the autopilot stabilizer trim. As the airplane speed increases or decreases
from the trimmed speed, the stabilizer is commanded in the direction to return the airplane to the
trimmed speed. This increases control column forces to force the airplane to return to the trimmed
speed. As the airplane returns to the trimmed speed, the STS commanded stabilizer movement is
removed.
STS operates most frequently during takeoff, climb and go-around. Conditions for speed trim
operation are listed below:
• STS Mach gain is fully enabled between 100 KIAS and Mach 0.60 with a fadeout to zero by Mach 0.68
• 10 seconds after takeoff
• 5 seconds following release of trim switches
• Autopilot not engaged

[CaptainSandL]

Originally Posted by ajamieson

On the MAX, are the CVR and FDR housed in the same unit? The Indonesian transport ministry doesn't seem to know... they say they've found one but not the other.

The CVR is located in the aft cargo hold and the FDR above the rear galley.
Photos here of them in situ if you want..
http://www.b737.org.uk/communications.htm#Cockpit_Voice_Recorder

http://www.b737.org.uk/flightinsts.htm#Flight_Data_Recorder

[AfricanSkies]

What beats me is why, in a new build jet, don't the systems recognise an unreliable airspeed, or an upset condition, and set a nominal N1 with A/T, command and fly a nominal pitch with F/D and A/P, fine tune it to level flight or a 100fpm climb using GPS altitude data and display a big F-O warning on the ADI saying something like 'AIRSPEED ANOMALY, LEVEL FLIGHT COMMANDED'

Why, when almost all parameters are known to the jet, and it has full capacity to control engines and flight controls, does the A/P just pack in when it's most needed?

[unworry]

A former colleague suggested this evening that a large piece of rudder or stabilizer were found early on in the search and reasonably intact ... some distance from the now main site of the fuselage wreckage.

Can anyone confirm this was the case or care to speculate whether a failure in the empennage could explain the profile suggested by the ADS-B data.

Honestly wondering ...

[The Ancient Geek]

A large, flat and relatively light object may drift significant distances while drifting to the bottom. Think of it as an underwater glider "flying".

[Tas62]

Originally Posted by unworry

A former colleague suggested this evening that a large piece of rudder or stabilizer were found early on in the search and reasonably intact ... some distance from the now main site of the fuselage wreckage.

Can anyone confirm this was the case or care to speculate whether a failure in the empennage could explain the profile suggested by the ADS-B data.

Honestly wondering ...

It was reported here (Aus) that the 'tail' had been found soon after the search began. I've not seen any images to confirm that though.

[infrequentflyer789]

Originally Posted by Capn Bloggs

The increasing percentage of Loss of Control accidents. Can you imagine what the safety record would be like if pilots could still fly aeroplanes?

What is the trend in LOC _rate_ per flight-hour or flight-mile?

% of accidents that are LOC is meaningless - a decrease in other causes will increase %LOC without any degradation in pilot skills. Reasons for decrease in other causes OTOH - better hardware engineering, GPS reducing NAV failures, better weather forecasting, EGWPS reducing CFIT, and probably some others I've forgotten. Of course if that was the case what we'd see is overall declining trend... which is what we do see.

[.Scott]

For what it's worth:

Anatashya Mengko, a mother of three who lives near the Jakarta airport, told ABC News that she saw smoke billowing from the underside of Flight 610 shortly after takeoff.

Also:

Officials in Indonesia on Thursday said they'd recovered Flight 610's data recorder from the bottom of the sea, but there could be more answers already back in the United States.

This aircraft type has a high-tech data system designed to send hundreds of gigabytes worth of information to the ground as it flies, including flight deck displays, maintenance data, software information and engine health.

It's called the Onboard Network System and every MAX 8 has a server installed in the aircraft, according to an article posted on Boeing's website.

https://abcnews.go.com/US/amid-despe...ry?id=58882494

[Cloudtopper]

[QUOTE=.Scott;10298737]For what it's worth:


Comments from locals are more often untrustworthy than usefull, although they do need to be taken into consideration

[Slow and curious]

Quote:
“Officials in Indonesia on Thursday said they'd recovered Flight 610's data recorder from the bottom of the sea, but there could be more answers already back in the United States.

This aircraft type has a high-tech data system designed to send hundreds of gigabytes worth of information to the ground as it flies, including flight deck displays, maintenance data, software information and engine health.

It's called the Onboard Network System and every MAX 8 has a server installed in the aircraft, according to an article posted on Boeing's website.“


How come nobody has mentioned this here before?

[alainthailande]

"Hundreds of gigabytes"? per aircraft? I seriously doubt this, the cost of sending this amount of data over sat links would be prohibitive.
Hope it's not optional, either, as the option not installed in MH370 that made investigators rely on dataless pings to dig out locations.

[The Ancient Geek]

How come nobody has mentioned this here before?

Because the data holders are correctly keeping quiet while they analyse whatever information they may have. Boeing are not the investigating agency so whatever information they may have will be submitted to the Indonesian investigators.

[DaveReidUK]

Originally Posted by Slow and curious

designed to send hundreds of gigabytes worth of information to the ground as it flies, including flight deck displays, maintenance data, software information and engine health

It would be more accurate to say that it's designed to collect hundreds of gigabytes worth of information as the aircraft flies.

Optionally, a subset of that information (EHM would be a good candidate, for obvious reasons) may be transmitted to the ground in real time, but only provided that the airline subscribes to some form of satcom-based IP connectivity. The balance of the data (or all of it, as the case may be) is downloadable once the aircraft is on the ground.

There's no suggestion that the onboard server is designed to be crashworthy, nor is it required to be, so don't bank on it providing any useful information.

[.Scott]

Originally Posted by alainthailande

"Hundreds of gigabytes"? per aircraft? I seriously doubt this, the cost of sending this amount of data over sat links would be prohibitive.
Hope it's not optional, either, as the option not installed in MH370 that made investigators rely on dataless pings to dig out locations.

They may be talking about that amount of data over a year or more. If it's 200Gbytes over 2000 hours of flight, that would be 100MBps - impressive, but not prohibitive.
And it is optional.

[Discorde]

A re-post of a comment on a different LOC incident: The confusion amongst the pilots in the 1996 crash of Birgenair Flight 601 was exacerbated by contradictory warnings (overspeed plus stick-shaker). Even if they had successfully recovered (using sensible pitch/thrust settings) they would have had to contend with the distraction of continued overspeed warnings. It's worth knowing which CBs to pull in the event of false overspeed or stick-shaker warnings so this distraction can be removed.

For the B757/767 the CBs are:
AURAL WARNING: B16 & H35
STICK SHAKER: C11 & J21