Airbus A321 Crashes in Sinai

[Venom800tt]

No it wouldn't.. (as in you're right, my original guess is wrong)

I'll have to read if the sensors are measured by barometric pressure or if has any sort of intelligent GPS (Ground Proximate System).

In aircraft GPS is Global Positioning System. There is a non-barometric based altitude sensing system called a radar altimeter, which is usually linked to a Ground Proximity Warning System. Newer aircraft since around the mid 1990's use Enhanced Ground Proximity Warning Systems, which combine both RA data and pitot-static barometric data, along with other info, to form a better picture of an aircraft's altitude, which includes terrain below. While the aircraft I work on don't have it, there is also 3D GPS, which uses 4 satellites instead of 3 to gain altitude data. That isn't as accurate as a RA, which itself is limited to only lower altitudes.
I just had to straighten that up lol...

 

[TenEightyOne]

In aircraft GPS is Global Positioning System. There is a non-barometric based altitude sensing system called a radar altimeter, which is usually linked to a Ground Proximity Warning System. Newer aircraft since around the mid 1990's use Enhanced Ground Proximity Warning Systems, which combine both RA data and pitot-static barometric data, along with other info, to form a better picture of an aircraft's altitude, which includes terrain below. While the aircraft I work on don't have it, there is also 3D GPS, which uses 4 satellites instead of 3 to gain altitude data. That isn't as accurate as a RA, which itself is limited to only lower altitudes.
I just had to straighten that up lol...

True, but the data as it's known so far is from the FlightTracker feed. As far as I'm aware that only tracks the first-level transmission of id, speed, hdg, and barometric altitude? The FDR will have a number of other sources available (as you note) which will be more accurate. The differences between those more accurate readings will be considered diagnostically. Until the report (or prelim report) is published we'll likely have little idea of what those wider altitude sources read.

 

[Swagger897]

In aircraft GPS is Global Positioning System. There is a non-barometric based altitude sensing system called a radar altimeter, which is usually linked to a Ground Proximity Warning System. Newer aircraft since around the mid 1990's use Enhanced Ground Proximity Warning Systems, which combine both RA data and pitot-static barometric data, along with other info, to form a better picture of an aircraft's altitude, which includes terrain below. While the aircraft I work on don't have it, there is also 3D GPS, which uses 4 satellites instead of 3 to gain altitude data. That isn't as accurate as a RA, which itself is limited to only lower altitudes.
I just had to straighten that up lol...

That's what I was alluding to just w/o the warning in it, as I would expect people to come back and say that's only viable when at low altitudes (which it's not) as like you said, it goes from RA.

 

[Michelin]

If so it would be very interesting evidence. A shoulder-launcher couldn't hit the plane at that altitude and Egypt say that the entire overflight region is firmly within their control.

There's a picture of the frontal wreckage on the BBC - I continue to think that this arrived at the ground intact and not pointing completely down, the wings are unnaturally "intact".

View attachment 473449

When I first saw the wreckage photo, I noticed how you could easily spot the wings... Either a explosion from inside or from the outside of the plane wouldn't leave the wings so "intact", as you said...

Actually, I was going to say that this accident is becoming weirder, but to be honest since the MH17 (and including it) every airplane accident reported in mass worldwide has been weird.

 

[TenEightyOne]

Either a explosion from inside or from the outside of the plane wouldn't leave the wings so "intact", as you said...

I guess it would if it occured somewhere to the rear of the wings - it's just the way that the front section appears to have come down intact and fairly level. If the plane's got 300 kias then an explosion out of the rear fuselage would be carried backwards from the wings.

 

[GTsail]

From what I've heard on the TV, an explosive decompression is very likely. But what caused it is not yet known.

What about catastrophic airframe failure just caused by airframe age and number of flights?

Similar to Aloha flight 243?

Perhaps a large crack in the fuselage opened up and maybe the tail fell off?

 

[Swagger897]

What about catastrophic airframe failure just caused by airframe age and number of flights?

Similar to Aloha flight 243?

Perhaps a large crack in the fuselage opened up and maybe the tail fell off?

20 years isn't that old on an airframe....


Unless it's been maintained properly..

 

[Michelin]

I guess it would if it occured somewhere to the rear of the wings - it's just the way that the front section appears to have come down intact and fairly level. If the plane's got 300 kias then an explosion out of the rear fuselage would be carried backwards from the wings.

Carried all the way to the back, you say, leaving most of the wings in place? Well, considering 300 kias = 345 mph = roughly 560 kph, it makes a lot of sense. Mind me a bit, I'm here more for curiosity and more on the learning side haha

 

[Swagger897]

Carried all the way to the back, you say, leaving most of the wings in place? Well, considering 300 kias = 345 mph = roughly 560 kph, it makes a lot of sense. Mind me a bit, I'm here more for curiosity and more on the learning side haha

Mind you, that's only ias, if there was any significant winds it would've blown all of that much further back..

 

[Michelin]

Mind you, that's only ias, if there was any significant winds it would've blown all of that much further back..

Oh. Dumb me. Thanks for the correction.

 

[Dennisch]

Interfax reports that there are unusual sounds heard on the voice recorder moments before the plane disappeared off the radar. What those sounds are haven't been released yet.

 

[TenEightyOne]

What about catastrophic airframe failure just caused by airframe age and number of flights?

Similar to Aloha flight 243?

Perhaps a large crack in the fuselage opened up and maybe the tail fell off?

Shouldn't happen (obviously), there's not really any such thing as an "old" aircraft due to equipment/airframe refresh cycles.

Aloha 243 was really a faulty design as much as anything, iirc, unluckily I believe it was the last on the production line not to have an extra layer on the skin - the design had already been changed by the time the next aircraft was built. I'd have to look that up to be sure though

 

[GTsail]

Shouldn't happen (obviously), there's not really any such thing as an "old" aircraft due to equipment/airframe refresh cycles.

True, but I've heard some un-confirmed reports that this particular plane had an earlier tail-strike incident (which I assume means that it hit its tail on the runway during a hard landing).

Could this tail-strike incident have weakened the airframe enough so that eventually there might be a airframe failure?

 

[TenEightyOne]

True, but I've heard some un-confirmed reports that this particular plane had an earlier tail-strike incident (which I assume means that it hit its tail on the runway during a hard landing).

It definitely did have a tailstrike, in Cairo 2001. Certainly investigators must consider this as part of their investigation. If the rear bulkhead separated then the effect would be as catastrophic as we've seen. There could still be other causes, either a related airframe failure or explosive human intervention.

EDIT: Tailstrikes normally occur on take-off, the plane over-rotates (lifts the nose too high). This tailstrike was indeed on landing - hell of a hard landing...

EDIT EDIT: I stand corrected, this Airbus Flight Ops note has landing tail strikes at a higher incidence. Source.

 

[Dennisch]

What if it's a major design flaw, seeing that the 321 is an elongated 320.

 

[Swagger897]

Sounds like they hit wind shear on landing, pushed down, then they entered a sink rate, and then pulled back too much...


Classic..

 

[Sanji Himura]

It definitely did have a tailstrike, in Cairo 2001. Certainly investigators must consider this as part of their investigation. If the rear bulkhead separated then the effect would be as catastrophic as we've seen. There could still be other causes, either a related airframe failure or explosive human intervention.

EDIT: Tailstrikes normally occur on take-off, the plane over-rotates (lifts the nose too high). This tailstrike was indeed on landing - hell of a hard landing...

EDIT EDIT: I stand corrected, this Airbus Flight Ops note has landing tail strikes at a higher incidence. Source.

This part of the report (on the last link) really got me troubled:

Tailstrike at landing often occurs on the second touchdown, following a bounce. It is often associated with a hard landing. [2] Although most of landing tailstrikes are due to deviations from normal landing techniques, some are associated with external conditions, such as turbulence and wind gradient.

This also doesn't look good for the airline:

Tailstrikes at landing generally cause more damage than tailstrikes at takeoff because the tail may strike the runway before the main gear, and cause damage to the aft pressure bulkhead.

Flight crewmembers may not always be aware that a tailstrike has occurred during landing, because the impact may not be felt. In these cases, a walk-around inspection performed by the flight crew before the next flight will ensure that the marks on the aircraft from the tailstrike are detected, and repaired, if required.

However, shallow damage that the flight crew did not detect, and that was therefore not repaired, may result in increased long-term risks (e.g. structural damage in flight, when the aircraft is pressurized).

If either the tailstrike was detected and not repaired or if a post-flight inspection wasn't done in 2001 to begin with (65% of all tailstrikes on that aircraft do occur on landing - Report pg. 1), then ISIS didn't do a bloody thing other than taking advantage of a situation. The airline is liable.

 

[Swagger897]

This part of the report (on the last link) really got me troubled:



This also doesn't look good for the airline:



If either the tailstrike was detected and not repaired or if a post-flight inspection wasn't done in 2001 to begin with (65% of all tailstrikes on that aircraft do occur on landing - Report pg. 1), then ISIS didn't do a bloody thing other than taking advantage of a situation. The airline is liable.

Normal landing techniques refers to following the glideslope down to the 1,000 feet past threshold. Anything else from that is non-normal.

 

[TenEightyOne]

If either the tailstrike was detected and not repaired or if a post-flight inspection wasn't done in 2001 to begin with (65% of all tailstrikes on that aircraft do occur on landing - Report pg. 1), then ISIS didn't do a bloody thing other than taking advantage of a situation. The airline is liable.

In this case an accident report was filed so the strike was observed by the crew and/or the tower/groundops.

I very much doubt that ISIS had anything to do with this, they'd claim the downing of a dead sparrow if they could.

I was genuinely surprised to find that more strikes occurred on landing - I'd always thought that over-rotation on takeoff was the primary cause. You live and learn!

EDIT: Also worth noting that this is only the third hull loss of this type, and the first caused (or potentially caused) by aircraft failure.

 

[mister dog]

This is what i believe now. Bomb smuggled onboard by the Jihadists and this footage is real:

 

[Dennisch]

This is what i believe now. Bomb smuggled onboard by the Jihadists and this footage is real:

That's from a game. I read it somewhere but I can't find it anymore.

 

[mister dog]

That's from a game. I read it somewhere but I can't find it anymore.

That's what people thought. Could be but i haven't seen proof of it.
Could just as well be a cheaper camera at maximum zoom level (looks like it)

 

[Dennisch]

That's what people thought. Could be but i haven't seen proof of it.
Could just as well be a cheaper camera at maximum zoom level (looks like it)

You don't seriously believe that's real footage from this crash, right?

 

[Swagger897]

That's from a game. I read it somewhere but I can't find it anymore.

I have to agree with this. Explosion looked like it occurred dead center of aircraft, which is where center tanks are.

Let alone, the tail never came off.

 

[mister dog]

You don't seriously believe that's real footage from this crash, right?

Well to be honest luckily i have never seen a plane explode in mid air, so i wouldn't know how to compare.

 

[Dennisch]

I have to agree with this. Explosion looked like it occurred dead center of aircraft, which is where center tanks are.

Let alone, the tail never came off.

The plane in the footage isn't even a A321. The wings are too far back, and the engines are on the tail.

 

[TenEightyOne]

This is what i believe now. Bomb smuggled onboard by the Jihadists and this footage is real:

Are death crash videos allowed?

RAF analysis says this is an aircraft with a tail engine (DC10, MD11 or military derivative) flying much lower. There's also a lack of disintegration... and a lack of corresponding fire on the tail at the crash site. IS Sinai are reported to have called the video "a fake"... I tend to agree, I think.

EDIT: An interesting question is what is the video of, if it's real?

 

[Swagger897]

Would be nice to have the metar of the time of the accident... Could easily disprove the tape.

 

[mister dog]

The plane in the footage isn't even a A321. The wings are too far back, and the engines are on the tail.

Engines look like they are under the wings to me. And even still how would you be able to see the exact contours of a plane on a zoomed in blurry video, at an angle.

About the tail not falling off, this video only shows the first moments if the plane was at 10km's height the descend would have been a lot longer, and the tail section might have fallen off afterwards.

 

[Swagger897]

Engines look like they are under the wings to me. And even still how would you be able to see the exact contours of a plane on a zoomed in blurry video, at an angle.

About the tail not falling off, this video only shows the first moments if the plane was at 10km's height the descend would have been a lot longer, and the tail section might have fallen off afterwards.

DC10: