Russian A321 Down in Egypt

[Say Again, Over!]

Any bodies found between the tail and the rest of the wreckage? Did the tail break forwart enough the it would have opened the passenger compartment?

[Kip Powick]

Any bodies found between the tail and the rest of the wreckage? Did the tail break forwart enough the it would have opened the passenger compartment?

Go here and look at the photos................

http://www.avherald.com/

[DEFCON]

Thanks Kip

I can't be certain, but it appears that the fan pictured is coated in a black oily like soot? Perhaps it's only the result of extreme engine surging?

It's early of course but I can't help but wonder if we're going to learn just how easy it is to break an aircraft once the computer protections are lost during dynamic events as we did back when the AA A300 lost its vertical fin some years ago.

[Don Hudson]

Hi boestar;

Re, "In some areas the data is somewhat less than perfect."

Yes, agreed, and the mistake many make, who are just wanting to know things, is accepting this as "flight data".

I am certainly no expert, but it seems to me that ADS is a traffic information/collision avoidance (ATC) tool, not primarily a tracking and data tool.

The problem with using FR24 data for flight data purposes is that there is no error recognition if data is corrupted, there are numerous receiving stations which are not time coordinated, (to a level that would make it a legitimate flight data tool), there are data dropouts but the biggest problem is that it takes some understanding of what one is reading to correctly interpret what is legitimate information and what is likely wrong and therefore misleading. It isn't a poor-man's DFDR nor is it an FDM tool. It is not data that makes one an expert, ;-)

The value in FR24 is similar to the value associated, for a short time, with the ACARS messages from AF447, which took us, as it turned out, in the correct direction, (loss of airspeed info) but could not take us further. As a result, all kinds of incorrect speculation occurred until, (to our - certainly my - shock), the data indicated that the airplane was stalled due to crew actions.

We didn't know what happened with AF447, and I suspect that if anyone had suggested such notions, (that the crew stalled their airplane by pulling it up to 15deg pitch at cruise altitude), very few would have accepted such a suggestion outright, perhaps taking it as just one possibility among many, far more plausible ones. It was to be two years before we really knew what happened.

[Woody Pusher]

ADS-B provides ATC with accurate/real-time position information and perhaps better than radar in some areas. So I don't see how this time stamp could not be accurate as well.

I acknowledge that ATC use of ADS-B in remote Canadian areas gives them positional data that would otherwise not be cost effective to obtain using SSR (ADS-C). The ADS-B receivers used by ATC are using GPS timing and not subject to "external" influences associated with hobbyist provided data used by services such as FR24 via the internet.

[DEFCON]

ISIS claims responsibility and offers video proof.

Who knows, but the video does appear disgustingly genuine.

[mo32a]

"We exclude technical problems and reject human error," Alexander Smirnov, a Kogalymavia airline official, said at a Moscow news conference as he discussed possible causes of the crash

Glad to see he is keeping an open mind.

[conehead]

ISIS claims responsibility and offers video proof.

Who knows, but the video does appear disgustingly genuine.

Link please?

[Kip Powick]

[blues deville]

I think ISIS needs to hire a new audio/video crew.

[dagger]

It's hard to take the video at face value. Seems too random, If a missile brought the plane down there would be a vapour trail, and military radar in Egypt or Israel would have a signature. I don't know how good the Egyptian radar is in that part of Sinai but you can bet that Israeli radar is absolutely second to none.

If a bomb, how did ISIS know which plane in the sky was the one with the bomb. Could have been one of several. Seems more likely there was an explosion, and someone with a cell phone camera - which means almost any adult - would have point the thing skyward. Half the people living in Sinai are Sunni militants.

[DEFCON]

The atmosphere is full of impurities and other variances that make optical filming of an aircraft at FL300, or higher, quite challenging.

If ISIS were to get a bomb aboard that employed a cell phone detonation trigger, all they'd have to do is, receive notice the plane had taken off, identify it with binoculars, and make a phone call while pointing the camera skyward.

[inchman]

Is it me or am I the only one that thinks this is an air-to-air video? You can see the wings and the smoke trail widens as it gets closer to the camera... just like a contrail.

For it to be air-to-air, not only did ISIS get hold of vehicle mounted SAMS but also put a stealth aircraft in the air to take the video... or they arranged a remote detonation and just happened to have an aircraft tailing the target.

Beyond the fact that I don't think this was a bomb, I don't buy a remote cell-phone detonation theory. Too much risk that it might not go off due to poor signal cell signal. But they are not beyond using human sacrifices, so someone on board with some sort of detonator (perhaps disguised as a cell phone or using cell-cell wifi or bluetooth).

So, the fact that ISIS is (in my mind) using a bogus video to "prove" their involvement discounts them.

[deicer]

This appears to me to be like the China Airlines crash involving a tail strike many years ago....

https://en.wikipedia.org/wiki/China_Airlines_Flight_611

[blues deville]

Is it me or am I the only one that thinks this is an air-to-air video? You can see the wings and the smoke trail widens as it gets closer to the camera... just like a contrail.

For it to be air-to-air, not only did ISIS get hold of vehicle mounted SAMS but also put a stealth aircraft in the air to take the video... or they arranged a remote detonation and just happened to have an aircraft tailing the target.

Beyond the fact that I don't think this was a bomb, I don't buy a remote cell-phone detonation theory. Too much risk that it might not go off due to poor signal cell signal. But they are not beyond using human sacrifices, so someone on board with some sort of detonator (perhaps disguised as a cell phone or using cell-cell wifi or bluetooth).

So, the fact that ISIS is (in my mind) using a bogus video to "prove" their involvement discounts them.

Totally agree. I'm not sure what this video is but I highly doubt it's the Metrojet crash.

[Woody Pusher]

For those needing confirmation of the FlightRadar24 air data, the following will provide Mode-S data from a single receiver covering the area of interest. Read the associated notes then download and examine the included .csv file.

http://www.flightradar24.com/blog/metrojet-9268-extended-mode-s-data-decoded/

This data has been made available to the BEA.

Overall, the aircraft slowed from a GS of 408kts to 47kts in 24 seconds - when the transmissions ceased.

As I suspected earlier, the DFDR and CVR possibly only recorded a few milliseconds before the aircraft broke up.

[Don Hudson]

Woody, thanks for posting this - clarifies a lot and also validates FR24 data when proper receivers are used, (vice small commercial/hobby units). The matter of interpretation remains of course but this is helpful information, tx.

[Woody Pusher]

The matter of interpretation remains of course but this is helpful information, tx.

Don, that interpretation will be a debatable point for light years to come. I only hope that those that look at the data can work with it on the basis that it was generated by the aircraft using all the tools that were available to it. Some may be able to initiate corrections based on what they see or deduce of the aircraft's performance, but others need to appreciate that the data points provided are about 500 milliseconds apart and a liberal dose of smoothing needs to be applied to make anything look like normal; which it obviously isn't.

On other forum I note that the fact that this S-Mode data, i.e. that sent by the TCAS system, and not ADS-B, seems to have been ignored. In other words the aircraft was sending TCAS compatible data that any other aircraft coming in conflict with its flight path would have automatically prompted its crew to act on. In this respect, the data presented is the last 24 seconds of what the aircraft was able tell of its predicament.

We know from AF447 that the TCAS is self monitoring, and that the transponder will cease sending data if it deduces that it is unreliable - which may or may not have happened in this case.

[DEFCON]

Inchman

I don't subscribe to a theory yet, but the bomb version remains quite plausible. Detonation doesn't have to be by cell phone either, pressure sensitive switches, timers and other mechanisms work well too.

As far as the video goes, it's pretty clear the aircraft involved is a twin engine swept wing current day machine. I haven't heard anyone from any quarter suggest this video can attributed to any other 'takedown' in modern history, which makes the ISIS claim somewhat more credible.

[DEFCON]

Woody

"others need to appreciate that the data points provided are about 500 m/s apart and a liberal dose of smoothing needs to be applied to make anything look like normal"

I've removed the question. I looked at the excellent chart you've provided and my question was answered.

[Don Hudson]

Woody, DEFCON, others interested in this fascinating topic, a personal interpretation: FWIW, I look at flight data as a strobe light in a dark room with say, people dancing. When the strobe flashes, we get a momentary "dataset", and in between it is not possible to say with accuracy what went on in between flashes. Who knows what each dancer on the floor was doing while it was dark... ;-)

We can create reliable, realistic data in-between flashes, (which is how animations are made so smooth, (and why they are not the analytical tool many believe them to be)), but I know that things can outpace the recording rate, particularly those parameters recorded at 1" or 1/2" rates.

I know that's obvious but the problem occurs when tacit assumptions are made regarding available techniques for filling in the dark spots.

We can extrapolate to make the data really fine-grained, (smooth), we can take a median (average) between data points to just double the number of data points, (not quite so smooth), but in the end such data points are not supported by real data but by guesses, (something like the algorithms that JPG files work under I think!).

Now where it comes to the mathematical (and even technical) details of filling in the dark spots, I rapidly run out of paved road with my knowledge of this stuff, but I do know that a control column/sidestick can move from stop to stop faster than the recording rate, and in one case at least, the data showed only the one CC/SS position. Along with spoiler deployment data, the potential for wrong conclusions was not only possible but probable.

Most of the time, it isn't a problem...until it is, and it is this kind of respectful understanding of what flight data is that I have offered cautions regarding the use of FR24 information. It is perhaps useful until the SSFDR/SSCVR recordings are read by a small group of specialists (including pilots, in my opinion), that tells the better, though-not-necessarily-complete, story.

In short, while the notion of "crowd-sourcing" has become popular with the world-wide presentation and use of common data by millions, (the search process for MH17 was an excellent example), I disagree that the same process works with FR24 or even flight recorder data. There are some things one has to know before good work can be done and even then, one still needs to suspend judgement in favour of curiosity.

[dagger]

The Brits are saying that the plane might have been brought down by a bomb. That's the word just out from David Cameron's office,

[boestar]

Don:

go to http://www.flightradar24.com/apply-for-receiver and scroll to the bottom for a description of the ADS-B receivers that are widely employed for Flight Radar 24. This unit does use the GPS timing signals.

Just as an FYI

[dagger]

https://twitter.com/WSJ/status/661963849399169025

[Don Hudson]

Thanks, boestar, will take a look.

Some airlines use "Skytrac", which does tracking, times and various parameter services as contracted with the air carrier, (so not available publicly). In fact, from experience, the service is exceptionally good and works for world-wide tracking.