Posts about: "DFDR" [Posts: 56 Pages: 3]

Someone Somewhere
2025-06-12T12:34:00
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Post: 11899162
Originally Posted by Spunky Monkey
For an aircraft that will likely have TOGA pressed and be at a high power setting (plus the RAT deployed) it sounds awfully quiet.
Perhaps the gear was down because they knew they were going to force land due to lack of thrust.
(Only a 738 driver), but the electric pumps to drive the hydraulics is much slower than the engine driven pumps and so flap selection / re-selection could be not as expected.

RIP to all involved.
787 gear and flaps/slats are both on the centre system, powered by 2x big electric pumps and no EDPs, so retraction should be minimally impacted by engine failure assuming electric power was still available and reconfiguration worked. Note the 787 has two generators per engine so generator failure is also unlikely to contribute, unless both engines failed taking out all four generators (and presumably no APU running).

Originally Posted by The Brigadier
Assuming we're not facing a repeat of the Boeing 737‑800 crash at Muan International Airport when loss of loss of both engines apparently also cut power to Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR)
From that thread, I believe it was discussed that on most/all other large transports, deploying the RAT re-powers the CVR/FDR. The 737 didn't have that happen because no RAT. You may still get a few second gap while the RAT deploys.

The 787 has 2x Enhanced Airborne Flight Recorders (EAFR), which each record both cockpit voice and flight data. I expect they are also fitted with the dedicated batteries that the Jeju was a year or two too early to require. Per the NTSB , the forward recorder has a 10-minute backup battery.

Hopefully flight data is not going to be an issue for this investigation.

Originally Posted by Sriajuda
Also, what is this discussion about the RAT? Unless someone has extremely quickly faked the audio on the video, it is pretty clear that the engines were running. (Both of them, there is some slight interference pattern I (maybe imagine) to hear.
The suggestion is that the buzzsaw/propeller sound is the RAT; it does sound a bit like an interference pattern, but you don't get the engine roar with it.

It's also maybe visible in a few stills (e.g. post 64).

Last edited by Someone Somewhere; 14th Jun 2025 at 06:01 .

2 users liked this post.

Monarch Man
2025-06-12T21:21:00
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Post: 11899746
Very sad day, let’s hope that the investigation is thorough and lacking any “political” or “cultural” interference, the aircraft sounded very quiet to me on the video…but it’s just a video, the DFDR and CVR should reveal all.

1 user liked this post.

CayleysCoachman
2025-06-12T21:26:00
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Post: 11899753
What a profoundly disappointing thread. In my days at the cutting edge, sometimes working the kinds of events which make big headlines here, we’d sometimes sit in the bar, on day four or five, seldom sooner as it was so full-on, and joke about the garbage being posted here, and by then in more-or-less full knowledge of the facts. I don’t have that inside line anymore but I still understand its nature, its scope, its precision, its clarity.

Ladies and gentlemen, get a hobby. Go fishing, read books, arrange flowers, spot birds, do crosswords. All of those things have some purpose and deliver some sense of achievement. What’s happening here is just puerile, pointless, conjecture. It’s ill-informed, if I’m kind, and importantly it’s hugely damaging to the many bereaved folk who ARE READING THIS THREAD in the hope of enlightenment, and whose night terrors may be filled with your ramblings. To them I apologise, on behalf of the industry. I’m sorry you have to be confused by these things.

I am hopeful that the investigation team will have almost full comprehension in a few days, curtesy of the flight recorders. It would be wonderful if they shared it promptly, but I suspect we’ll wait at least two years, perhaps much more. For me, that’s the issue here, the investigatory world’s unwillingness to share facts.

14 users liked this post.

Professor Plum
2025-06-12T21:35:00
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Post: 11899759
Originally Posted by CayleysCoachman
What a profoundly disappointing thread. In my days at the cutting edge, sometimes working the kinds of events which make big headlines here, we\x92d sometimes sit in the bar, on day four or five, seldom sooner as it was so full-on, and joke about the garbage being posted here, and by then in more-or-less full knowledge of the facts. I don\x92t have that inside line anymore but I still understand its nature, its scope, its precision, its clarity.

Ladies and gentlemen, get a hobby. Go fishing, read books, arrange flowers, spot birds, do crosswords. All of those things have some purpose and deliver some sense of achievement. What\x92s happening here is just puerile, pointless, conjecture. It\x92s ill-informed, if I\x92m kind, and importantly it\x92s hugely damaging to the many bereaved folk who ARE READING THIS THREAD in the hope of enlightenment, and whose night terrors may be filled with your ramblings. To them I apologise, on behalf of the industry. I\x92m sorry you have to be confused by these things.

I am hopeful that the investigation team will have almost full comprehension in a few days, curtesy of the flight recorders. It would be wonderful if they shared it promptly, but I suspect we\x92ll wait at least two years, perhaps much more. For me, that\x92s the issue here, the investigatory world\x92s unwillingness to share facts.
I wholeheartedly agree.

RIP. Very sad day.

Thank you to the mods for clearing out the junk. (I presume you do it for free?)

9 users liked this post.

White Knight
2025-06-12T23:38:00
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Post: 11899838
Originally Posted by CayleysCoachman
What a profoundly disappointing thread. In my days at the cutting edge, sometimes working the kinds of events which make big headlines here, we\x92d sometimes sit in the bar, on day four or five, seldom sooner as it was so full-on, and joke about the garbage being posted here, and by then in more-or-less full knowledge of the facts. I don\x92t have that inside line anymore but I still understand its nature, its scope, its precision, its clarity.

Ladies and gentlemen, get a hobby. Go fishing, read books, arrange flowers, spot birds, do crosswords. All of those things have some purpose and deliver some sense of achievement. What\x92s happening here is just puerile, pointless, conjecture. It\x92s ill-informed, if I\x92m kind, and importantly it\x92s hugely damaging to the many bereaved folk who ARE READING THIS THREAD in the hope of enlightenment, and whose night terrors may be filled with your ramblings. To them I apologise, on behalf of the industry. I\x92m sorry you have to be confused by these things.

I am hopeful that the investigation team will have almost full comprehension in a few days, curtesy of the flight recorders. It would be wonderful if they shared it promptly, but I suspect we\x92ll wait at least two years, perhaps much more. For me, that\x92s the issue here, the investigatory world\x92s unwillingness to share facts.
Yep. The families of 250 Gujaratis are reading PPRUNE🙄🙄\x85

Get off your high horse; as sad as the posts may be it is a RUMOUR network! I think there\x92s an awful lot of nonsense posted here but people are ENTITLED to speculate. Unless of course you believe in an Orwellian World🙄🙄

14 users liked this post.

DaveReidUK
2025-06-13T11:17:00
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Post: 11900370
Originally Posted by The Brigadier
All to easy to surmise the contents will be tampered with at the request of politicians/investors
I think the word you are looking for is "inconceivable".

AFAIK , both the NTSB and UK AAIB are by now onsite to assist the investigation at the request of the Indian AIB. The suggestion that they wouldn't notice, or would be party to, funny business with the flight recorders is ridiculous.

14 users liked this post.

Tom Bangla
2025-06-13T11:37:00
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Post: 11900392
Originally Posted by DaveReidUK
I think the word you are looking for is "inconceivable".

AFAIK , both the NTSB and UK AAIB are by now onsite to assist the investigation at the request of the Indian AIB. The suggestion that they wouldn't notice, or would be party to, funny business with the flight recorders is ridiculous.
I believe and hope you're right, Dave. But don't be so quick to eliminate unorthodox business. India's a funny old country.
pug
2025-06-13T12:16:00
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Post: 11900431
Originally Posted by Buster15
I understand that the FDR has been recovered from the crashed 787.
Could anyone tell me how many engine parameters are recorded and what is the sample rate.
Thank you.
Most likely anything between 256 and 1024wps, individual parameters will vary with regards sample rate. Not au-fait with 787 but other Boeing aircraft may have dataframes relative to the original owner requirements (though this is unlikely to vary much given my experience with Boeing aircraft). I\x92m not sure if GE have a real time EHM feed like RR? Anyhow, and not wanting to speculate too much, if there was anything engine related it would certainly show up on the DFDR and GE could possibly even know that by now if they are equipped with real time health monitoring. In my opinion, for what it\x92s worth, the CCTV footage is consistent with flap retraction instead of gear, something that would also be easily identifiable upon review of the FDR which will be reported upon in due course.

Last edited by pug; 13th Jun 2025 at 12:52 .
mikepl
2025-06-13T12:47:00
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Post: 11900477
Originally Posted by Someone Somewhere

The 787 has 2x Enhanced Airborne Flight Recorders (EAFR), which each record both cockpit voice and flight data. I expect they are also fitted with the dedicated batteries that the Jeju was a year or two too early to require.
Indeed GE EAFRs have internal battery backup but it only server as a power source for locator beacon. The a/c might have been equipped with RIPS (an independent power supply for recorders) but for instance for 737 it's user selectable option, not sure how that relates to 787 - maybe they became part of standard equipment.
gear lever
2025-06-13T13:28:00
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Post: 11900521
Having experience of many crash sites over a long career, taking off without flaps with the config horn/ warning blaring (or not if u/s) is a possibility Also selecting flaps up, instead of gear up at the positive rate of climb call, is also not unheard of and has happened. Both engines failing/ losing power at rotation/ initial climb out would be extremely rare, but not impossible. With the descent and lack of climb clear, unless a mistake of retracting flaps instead of gear, why wasn't the gear selected up as dragging that around is only going to end one way.
he sound from the well documented video would suggest the engines were running, but were certainly not selected to TOGA/ full power which you might expect when faced with high buildings growing larger in the windshield.
Due to the tail section being relatively intact, the CVR/ DFDR will be downloaded very soon, if not already, so we will all know shortly....

1 user liked this post.

sSquares
2025-06-13T17:04:00
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Post: 11900697
The nose gear angle suggest that the "gear-up" was selected and a dual engine failure happened at the same time, with the hydraulics failing and possible RAT deployment.. The APU was not running and everything, except the flight recorders, might be powered down and restarted at a very low altitude.

Very scary.
atakacs
2025-06-13T17:33:00
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Post: 11900724
Bit surprising that we don't have confirmation of the 2nd FDR recovery by now, especially with the seemgly realtively intact tail section. The
DFDR was reportedly recovered from this rooftop:




The CVR can't far away and muss be a rather high priority search item.

Interdentally I have read some reports mentioning a DVR (Digital VIDEO recorder). Is AI fitting such devices in their aircrafts ?
Return_2_Stand
2025-06-13T17:47:00
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Post: 11900737
Originally Posted by atakacs
Bit surprising that we don't have confirmation of the 2nd FDR recovery by now, especially with the seemgly realtively intact tail section. The
DFDR was reportedly recovered from this rooftop:

The CVR can't far away and muss be a rather high priority search item.
Are the FDR and CVR not combined in the 787? (One in the front and one in the tail, but recording the same info??)

Last edited by Return_2_Stand; 13th Jun 2025 at 17:58 .

1 user liked this post.

QDM360
2025-06-13T18:47:00
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Post: 11900797
Originally Posted by atakacs
Bit surprising that we don't have confirmation of the 2nd FDR recovery by now, especially with the seemgly realtively intact tail section.
It's not surprising. The 787 was designed with a modern digital flight recorder (Enhanced Airborne Flight Recorder, EAFR). It does both - records data and voice. No more separation of CVR+FDR. Just one device.

But the 787 was equipped with two redundant recorders. One in the aft, one in the front compartment. Both record identical data. If one of them was found in usable condition, then they're good. It will already have all the data they need.
nachtmusak
2025-06-13T21:03:00
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Post: 11900901
Originally Posted by ams6110
In fairness, recalling a "green light" is a pretty specific thing. A "sensation of thrust" from a seated passenger who may not even be an experienced flyer could be describing any feeling of movement or the illusion of same.
In the spirit of fairness there is another sensation that can be interpreted as "increased thrust" that a passenger is equally if not more likely to be talking about : a change in [perceived] engine noise level and/or quality.

Personally I don't hear much of the engines as the plane moves away from the cameraperson in the phone video, while the sound of impact is clearly discernible. If anyone can hear the engines well enough to tell if there is a significant change in their tone or volume, that would be valuable info, I think. Alternatively whatever increase in noise was heard started before the recording starts. In that case I suppose the "RAT theorists" would say it was the droning of the now-deployed RAT, with the assumption that it would be audible from inside the cabin (things like flap and landing gear actuation certainly are, so that isn't all that far-fetched). On the other hand, the "flap theorists" would probably say it was the crew firewalling the thrust levers in response to the inability to climb, which isn't far-fetched either.

Either way we will know soon enough what actions the pilots did or didn't take, since the various flight recorders should be found fairly easily in good condition.
neila83
2025-06-13T21:31:00
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Post: 11900927
Originally Posted by nachtmusak
In the spirit of fairness there is another sensation that can be interpreted as "increased thrust" that a passenger is equally if not more likely to be talking about : a change in [perceived] engine noise level and/or quality.

Personally I don't hear much of the engines as the plane moves away from the cameraperson in the phone video, while the sound of impact is clearly discernible. If anyone can hear the engines well enough to tell if there is a significant change in their tone or volume, that would be valuable info, I think. Alternatively whatever increase in noise was heard started before the recording starts. In that case I suppose the "RAT theorists" would say it was the droning of the now-deployed RAT, with the assumption that it would be audible from inside the cabin (things like flap and landing gear actuation certainly are, so that isn't all that far-fetched). On the other hand, the "flap theorists" would probably say it was the crew firewalling the thrust levers in response to the inability to climb, which isn't far-fetched either.

Either way we will know soon enough what actions the pilots did or didn't take, since the various flight recorders should be found fairly easily in good condition.
Good summary, I'd just say the thrust levers definitely weren't firewalled. The plane lost a huge amount of speed by impact. This single fact should be enough to end the flap retraction theory. It lost a huge amount of speed while descending - now what might cause that? The gear also begin the retraction process (bogies tilting). The obsession with flaps when there isn't a single piece of evidence for it is very odd. (not suggesting you are guilty of it btw).

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bille1319
2025-06-13T21:56:00
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Post: 11900953
Originally Posted by directsosij
The recordings are simply of too low quality to draw any conclusions from.

If it was dual engine failure shortly after rotation, that is very bad luck and I doubt any crew could recover from something like that.

I could speculate further but I think it\x92s just too hard to say without better quality footage or FDR data.

Reports say that one of the black boxes have been recovered and the search continues for the other one. Apparently the B787 flight recorders log voice as well as data so only one is suffice if not damaged.
Alwaysairbus
2025-06-14T08:00:00
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Post: 11901227
As much as it's been interesting to read the many weird and wonderful theories, i think everyone should hold on, specially when making assumptions about the professional flight crew and maintenance engineers. The flight recorder readouts and flight deck voice recorder (whatever they are called on the 787) will 100% explain the events leading up to the tragedy. Hopefully the thorough investigations and findings will be transparent and lessons learned are immediately put in to effect.
FullWings
2025-06-14T16:33:00
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Post: 11901629
Originally Posted by Four Turbo
Has the rest of the fleet been grounded? If not they must have a fair idea of what caused this. And it is not something that is about to happen elsewhere.
AFAIK no groundings yet but we do not know for sure that there has been a successful readout of the DFDR. If it sustained damage or the interface electronics are non-functional, it\x92s not unusual for them to be taken to a secure lab at a *AIB where experts can attempt recovery using whatever advanced methods they have available. This may take time as they don\x92t want to lose data in rushing to extract it.
V1... Ooops
2025-06-15T03:40:00
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Post: 11902077
Originally Posted by lucille
...I guess if no directives come from Boeing or the FAA in the next 2 weeks, it can be presumed that a systems failure from which recovery was impossible was unlikely.
I agree. The subject aircraft was fitted with two Enhanced Airborne Flight Recorders (EAFRs), one of which is located forward and one in the rear. These recorders capture both voice (traditional CVR) and data (traditional FDR), and provide redundancy. One - presumably the one in the rear - has already been recovered.

Two weeks is likely long enough for the investigators to determine if a systems failure might, in any way, have been a possible cause. I am sure that if there is any reason to suspect that a systems failure may have been a probable cause, or even contributed in any way to the accident, Boeing, GE, the FAA, or the Indian DGAC will promptly advise 787 operators.

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