EgyptAir 804 disappears from radar Paris-Cairo

[PJ2]

Glad we're on the same page, vapilot...

gums, the airplane is more sensitive, (as discussed on the AF447 threads) but still isn't a handful - tiny, tiny stick movements...QED.

[PersonFromPorlock]

I may be missing something obvious, but wouldn't the existence of more than one debris field indicate a midair breakup into a number of large pieces, with the pieces following their own trajectories to the surface and disintegrating further on the way down and/or on impact?

[Lonewolf_50]

@silverstra

There is a big difference between releasing your full capabilities and making yourself look incompetent. All they need do is degrade the quality of the proper surveillance photos by 90% and release those. But to release an iPhone video through a frosted window on an official USN website, is a PR blunder of epic proportions. But having watched a recent documentary on Canadian SAR aircraft, where the equipment was three decades old and barely worked, I do wonder.

I call shennanigans. What's your beef with the USN?
"PR blunder of epic proportions?" (Hyperbole much?)
Methinks the young lady protesteth overly much.

@Old Boeing Driver

Over dependence on automation has a history in aviation a few decades old. If you'd like to PM me, I can share with you a rotary wing angle on that not suitable for this thread.

[MrFixer!!!]

Its clear whatever happened, happened very quickly!!

People staring at ACARS transmission and speculating at what happened, might also want to look at "How" ACARS work? Even if its a simultaneous failure of systems, transmision is made after a confirmed failure based on the priority.

So even if all systems failed at the same time, it "appears" there is a time lag between first failure and the last message transmitted.

Might be worth looking at the Bus powering all the transmitted "systems". Window sensors & window heat sensors are routed through WHC, a failure of that will trigger these messages. Lav smoke & Avionics smoke go through SDCU. FCU 2 & SEC3 trigger the same way.

Common denominator is wiring and the powering Bus of these computers. Very quick catastrophic damage and only a handful of messages that could be transmitted while all the systems worked.

Only time will tell what happened & how it happened, if we ever get to know the truth!!!

[Ranger One]

Its clear whatever happened, happened very quickly!!

People staring at ACARS transmission and speculating at what happened, might also want to look at "How" ACARS work? Even if its a simultaneous failure of systems, transmision is made after a confirmed failure based on the priority.

So even if all systems failed at the same time, it "appears" there is a time lag between first failure and the last message transmitted.

That IS a point. Can a systems guru confirm exactly how ACARS transmits this stuff in real time? Do the timestamps on the ACARS messages reflect the real times of separate transmissions of individual events - or one single 'squirt' of data listing the last few events and the time they happened?

I've seen quite a few posts assuming that the listed messages meant ACARS sent several transmissions over a 3-4 minute period but I'd appreciate confirmation from a geeky type who understands the innards of these boxes that this really is a good assumption!

[pattern_is_full]

I may be missing something obvious, but wouldn't the existence of more than one debris field indicate a midair breakup into a number of large pieces, with the pieces following their own trajectories to the surface and disintegrating further on the way down and/or on impact?

Reasonable question.

However, AF447 definitely hit the ocean in one piece, and there was a spread of floating debris of up to 3 miles before the first bits were located, a day after it disappeared.

Very buoyant debris that stays mostly on or sticking above the water surface may "sail" with the winds in one direction, whereas debris that is just barely awash may move only with the water currents. Or a combination of the two, diverging with every hour on the surface. Things may break loose underwater after the impact, and float to the surface through varying currents, surfacing some distance from "ground zero."

Or - the aircraft may have broken up only in the last moments, when its dive exceeded structural limits, long (relatively) after whatever "event" occurred at 35000 feet. 5000-10000 feet can be high enough to scatter debris.

So it does not automatically imply the breakup (if any) was the original event.

[MickG0105]

As I understand it the last ACARS message - 00:29Z 2700 F/CTL SEC 3 FAULT - indicates a fault in the No 3 Spoiler and Elevator Controller. That being the case, the spoilers would have retracted. If the crew were following the Smoke Procedure they almost certainly would have been descending to FL100 when SEC 3 faulted.
I'm not a driver but I imagine that the retraction of the speed brake while executing an emergency descent would be troublesome.

[andrasz]

I may be missing something obvious...

As pointed out by several posters, the state of the wreckage (and body parts) as shown on photos released so far and/or described fairly conclusively indicates that the aircraft hit the water in one piece at a very high speed in an aerodynamically clean configuration.

At those speeds any loss of a major structural component would immediately cause an upset and rapid disintegration in air, and speed of individual components/bodies would then quickly decay due to aerodynamic drag, with little further damage on hitting the water.

[WhatsaLizad?]

19 pages of drivel, mainly driven by well meaning enthusiasts and self loading freight fantasizing about all sorts of conspiracy theories.


Just proves my long standing point.


After every tragic accident, there should be two threads on PPrune. One for well meaning, but dreadfully uniformed enthusiasts and those that may be less informed on the technical aspects of any accident. The second thread should be for aircrew with relevant experience on the class of aircraft, operational conditions as well as cabin crew, ground tech crew, engineers as well as others outside the general aviation spectrum that may possess information and skills that relate to a particular incident. For others that don't have the requisite experience on the thread, just refrain from posting. Thanks.

[spinex]

19 pages of drivel, mainly driven by well meaning enthusiasts and self loading freight fantasizing about all sorts of conspiracy theories.


Just proves my long standing point.


After every tragic accident, there should be two threads on PPRuNe. One for well meaning, but dreadfully uniformed enthusiasts and those that may be less informed on the technical aspects of any accident. The second thread should be for aircrew with relevant experience on the class of aircraft, operational conditions as well as cabin crew, ground tech crew, engineers as well as others outside the general aviation spectrum that may possess information and skills that relate to a particular incident. For others that don't have the requisite experience on the thread, just refrain from posting. Thanks.

You forgot the most important additional thread of the lot, the earnest, oh so superior pointing out of all the drivel posted by just about everyone other than yourself.

By and large, the mods are on to it, even if they were with the benefit of hindsight a little hasty in removing the ACARS screenprint and at present the choice is between one post a day with the meagre pickings from the various authorities, or the current picking over of the possibilities. There is something to be learnt from this, including by the poster who didn't realise that some older airframes did indeed have internal access to the avionics bay - or the unlikely, but possible, unhappy results of a drink spillage. My 2c

[Feathered]

Originally Posted by silverstrata

There is a big difference between releasing your full capabilities and making yourself look incompetent. All they need do is degrade the quality of the proper surveillance photos by 90% and release those. But to release an iPhone video through a frosted window on an official USN website, is a PR blunder of epic proportions. But having watched a recent documentary on Canadian SAR aircraft, where the equipment was three decades old and barely worked, I do wonder.

Incompetent? PR blunder of "epic proportions?" I strongly disagree and your claim has no basis in fact. US Navy does not need or want to fly around the Med just to do a PR patrol or to show off images (and what are you claiming they should show images of?) . The photo you saw merely indicated that USN has a search in effect, it has assets joining the international search effort, and there is no need to say anything else at this time. If they find something relevant, they will report it to the incident command of the search effort.

The Navy aircraft is not a news helicopter. Even if they wished to show off better capabilities, there is a long process to move sensitive details to a public forum and it has nothing to do with simplistic claims like "degrade by 90%" or whatever. Instead of doing this for images of the empty sea, resources are much better spent elsewhere, even if you just want to look at some reconnaissance details.

[D Bru]

new docs

http://www.ahram.org.eg/News/181912/...5;ئ.aspx

State owned newspaper al-Ahram publishes new docs. Can't somehow make them bigger and with that more legible.



EDIT: this ACFT Technical Log seems for sector CAI-CDG, not CDG-CAI! A more complete pic is here:
http://arabic.cnn.com/world/2016/05/...gyptair-ms-804

[andrasz]

al-Ahram publishes new docs

The one on the left is a printout of the ACARS messages, nothing new. The other is the maintenance release log for the CAI-CDG sector, noting NIL defects. Has no bearing on the state of the aircraft on the CDG-CAI leg (though if it were released with any MEL'ed defects, we'd probably know by now).

[MrPeabody]

Originally Posted by andrasz

The one on the left is a printout of the ACARS messages, nothing new. The other is the maintenance release log for the CAI-CDG sector, noting NIL defects. Has no bearing on the state of the aircraft on the CDG-CAI leg (though if it were released with any MEL'ed defects, we'd probably know by now).

I think you're reading it wrong; it's the log entry for CAI-CDG and maintenance release for CDG-CAI sector.

Nil Defects is for CAI-CDG; the info is then noted and transit check accomplished; then the maintenance release is for CDG-CAI. Also you can make out the French 1's in the tyre pressures.

[llagonne66]

@Ranger One on ACARS

Please go back to AF447 Interim Report #1 section 1.6.9.2 to get an explanation on how ACARS messages are managed and time-stamped.
https://www.bea.aero/fileadmin/docum...cp090601e1.pdf
Sorry, the link is for the French version as I cannot find the English one from the BEA website
You can work it out with Google Translate

[DaveReidUK]

Originally Posted by andrasz

The one on the left is a printout of the ACARS messages, nothing new.

Clearly it is the ACARS log, but the third-from-right column, headed "Priority" is interesting.

Whereas in the original log from a few days ago it simply had codes "L", "H", and "S" in that column, and it didn't take a genius to deduce that the first two meant "Low" and "High" respectively, it now seems that "S" indicates "Spurious", if my eyes aren't deceiving me.

That's shown against the "SMOKE LAVATORY SMOKE" entry, so I guess the question is, if that can be discounted, how does that alter the putative sequence of events, if at all?

[Coagie]

Originally Posted by D Bru

http://www.ahram.org.eg/News/181912/...5;ئ.aspx

State owned newspaper al-Ahram publishes new docs. Can't somehow make them bigger and with that more legible.

rgds,

Dutch

EDIT: this ACFT Technical Log seems for sector CAI-CDG, not CDG-CAI! A more complete pic is here:
???? ???? ??????? ??????? ??????? ?? ??????? ???? ?? ????? ????? ??? ???????"MS804"? - CNNArabic.com

I cropped them, but they're pretty low resolution. The CNN one is more complete, but the newspaper one is a little higher resolution:

[D Bru]

re SysDude's post

Seems that the Greeks are sticking to their interpretation of the radar data (90° left, 360° right).

"We will start sending the main data from tomorrow, including the radar tracking and the conversation with controllers," one source who requested anonymity told Reuters.
....
The source close to the probe, and a second defense ministry official, said Greece stuck by its account that the plane had lurched violently in mid-air before it disappeared from radar screens. There has already been an exchange of information with Egypt, the sources said.

Egyptian authorities said they did not see the plane swerve and lose altitude before it vanished from their radars.

Greek Defense Minister Panos Kammenos last week said the aircraft took a sudden 90 degree turn, before flipping 360 degrees in the opposite direction and plunging from a cruising altitude of 37,000 feet to 15,000 feet, then vanishing.

"The picture we have off our radars is what the minister announced... we insist on that," the defense official said."

[andrasz]

"The picture we have off our radars is what the minister announced... we insist on that", the defense official said.

Oh dear... As we know from the Rt. Hon. Jim Hacker, one should never believe anything in politics unless it is officially denied. Works in reverse too...

[Volume]

the state of the wreckage (and body parts) as shown on photos released so far and/or described fairly conclusively indicates that the aircraft hit the water in one piece at a very high speed in an aerodynamically clean configuration.

Considering the very low amount of parts found yet, they may very well belong to what the first explosion/failure has blown from the aircraft, with the main wreakage still not being discovered. Thinking of the recent Daallo incident, United 811 or the THY DC-10 near Paris in the 70s, such a scenario is also still possible.
Otherwise I do agree, if the items found so far are indeed representative for all debris, this indicates a high speed impact, which only is possible for a largely intact aircraft.