So what happens when an aircraft lands short with EMAS present? Can you assume that in such cases the aircraft will be landing flat and not a gear first with a tendency to roll.

SGC

Spot on - and it's not just 'at the end of the runway'. Thinking of the Spanair crash in Madrid where there was/is a ravine and a stream at the side of the runway. There was plenty of runway left but the ravine drop contributed to the breakup of the aircraft and the severity of the injuries (although paradoxically the water lessened burn severity).

Sunamer

Think of it in terms of a closed system in Newtownian mechanics and the conservation of momentum, rather than energy. If you could work out what speed the nosewheel was going, then I cant see how the speed of the aircraft at that point would be less than that, although I agree that it is likely that it would be more. :rolleyes:

Machinbird;

Thanks for the response. Agree, interesting topic but won't take it further as indeed it doesn't apply here.

Awaiting photos and/or the FDR to see the position of the reversers and thrust levers. Lomapaseo's photos do seem to show low rotational speed in that engine.

Also, I'm thinking of the amount of destruction of the airframe in the TAM A320 overrun accident at Sao Paulo - it was almost complete but for the empennage but here much of the fuselage remains in a single piece, looking more like the Etihad A340-600 31kt ground-test collision with a blast fence at Toulouse, though the Red Wings aircraft fractured/separated at the cockpit and empennage. The lower cockpit area and the fracturing of the fuselage dissipated much of the forward energy but the fuselage remained largely intact.

Understand the various calculations showing high speed but to me from the available photos the wreckage doesn't look like a high-speed, (=> 100kts) overrun. Perhaps the level of destruction in the TAM case was the vertical face of a concrete building while in the Red Wings overrun the ground was sloped and the same energy (about 100kts) was indeed absorbed by the undulating ground and the burm leading up to the freeway. In any case, we'll see what the speed was when/if the FDR data is eventually made available.

This accident damage strikes me as very similar to the TACA A320 over-run at TGU in 2008. They departed the runway at 54 knots into comparable terrain features.

PJ2, in the Congonhas accident there was a small berm at the edge of the airfield as well, around 60cm high if I recall correctly. The fully laden aircraft traversed the road and impacted the TAM building, about 100m from the berm at the edge of the field and 10-12m lower, and head-on.

Would the fact that the TAM Airbus managed to "fly" that distance not indicate, in itself, a much higher impact speed than the 204? Or would the 204 not have bounced off the nose gear and concertinaed had it been heavy?

broadreach;

Re, "Would the fact that the TAM Airbus managed to "fly" that distance not indicate, in itself, a much higher impact speed than the 204? "

Yes it would and that's exactly my point.

Re-reading my post I wasn't sufficiently clear in stating that I think the 204 overrun was a low-speed accident. I think it was closer to the Etihad and (thanks, Machaca), TGU accident speeds, (30 to 50kts).

The plot thickens...

a flight attendant was interviewed from his hospital bed and declared that the braking was normal

Braking was normal? Unless the aircraft touched down extremely late and a high-speed overrun occurred in spite of normal braking, would this indicate an attempt to take power again and go around?

- now, do we 'accept' this or dismiss it as inept journalism like other 'quotes'? Did this come from the investigation or the media?

Last minute go-around attempt?
 

This is, of course, completely speculation, but considering the speed at which the aircrafyt departed the end of the rwy makes me think there may have been a normal landing, a deceleration/braking attempt, then a realization the aircraft will not stop, then a go-around attempt, which of course is rejected at the realization the airplane will not fly.

The Russian crews may not always have sufficient training to know exactly what to do in this kind of situation, lack of standardization, specifically with smaller operators.

Captain had 15000 hours, so he must have been half experienced!

Come on guys, you've had your fun. Reality is that none of you know what really happened. We've had enough drivel from some of you. Put it to bed and wait for the official and factual accident report to come out. :*

Xcept at 30-50 knots, should we look at crashworthiness? :ugh:

IIRC, I remember once reading on an aeronautical site, some days after the 204 Aviastar crash out of Moscow, that RWZ CEO/President was not at all satisfied with their 204 fleet (in 2010), and was desperately trying to change it ASAP, due to a serie of no-good events and occurences...im trying to find the link.

On forumavia somebody from 204 make test on real plane:

Dashcam video speed information
 

Following the discussion of the debris speed, but without looking to check the numbers from earlier posts this is what I reckon.

The aircraft's visible diving down the bank to the right before the debris arrives, and seems to be moving quickly enough to cover its length in a couple of seconds, which would be about 20-25 m/s, about 40-50 knots. It definitely doesn't look like 100 knots. It seems to be driving not flying.

The wheel bounces off the bottom of the light gantry, crossing four lanes of the road in what looks like a bit more than two seconds - that's only about 10 m/s, so the wheel I reckon is moving slower than the aircraft was when it was released.

To correct both of these numbers, there's the factor of almost 45 degrees that the runway is angled with the road, so both should be higher by about 1.4.

I'd guess about 35 +- 15 knots for the wheel, and 60 +- 20 knots for the aircraft.

Can people remember that even if this is an accurate report of a credible interview in a respectable publication, eyewitness evidence recollection in situations like this is notoriously unreliable. Didn't another surviving FA say that this was the second attempt to land?

I'm not saying it is in this case, just that this is another time to wait for the DFDR evidence.

Of course - the flt attendant must have been heavily medicated so should be taken w lots of salt

Relative Speeds A/C & dashcam car
 

Seems to me, the aircraft was moving significantly faster that the car with the dashcam.
Car on a steady heading, aircraft also on a steady heading, aircraft moving from the side towards the nose of the car, and would have actually arrived at the theoretical point of intersection first as indicated by the snow being thrown up in front of the car.

I don't know how fast the car was going. Looked to be around 60 mph or 50 knots but someone on this forum must have some idea of what the typical open road speed is for that stretch of highway.:hmm:

Same principles apply as relative motion between aircraft inflight.

Hi Machinbird..

Without adding for parallax to augment rate, I still get two fuselage lengths in a bit over one second. That is wicked fast, so I go to what I think would be a very conservative value of 90 knots. Two lengths (300 feet) in two seconds is still ninety knots. It could 115+.

Anything is possible, but your take seems to affirm more velocity than 50-60 knots.

Whatever it is, the bottom line is way too fast to survive, and suggestive of added thrust or uncommanded thrust well after touchdown, imho.

Sad bad day...

This is all endless speculation.
The crew+a/c hit mostly a snow lined concrete wall and the impact was unsurvivable.
Period.

I also saw the interview, widely diffused on russian TV
(go question the wisdom and credibility instinctively!).

I challenge anyone to bang their head against the remains of disintegrating (car/aircraft/boat/) without a helmet, decellerating from 90mph+, & remember anything worth anything.

They did roughly the same thing for the (ONE) survivor of the Jaroslavl Yak42 accident.
I think this kind of media intervention is blatent disrespect for the deceased.

A lot of speculation on this forum.:confused: However that is human nature. We all want to know. What interests me is will the Russian authorities come up with a true and honest report eventually?

Big country, long holidays
 

Russian only today opened for business after the New Year and subsequent Orthodox Christmas holidays. It's unlikely that much analytical investigation activity (as opposed to immediate evidence gathering) has taken place so far.

EDIT: Indeed, the party lasts even longer that I thought. Jan 9th is the first working day of the year 2013.

- End of long holidays (first working day) will be tomorrow.
- MAK have no less than 30 days for report - 15 for evidence gathering and 15 for composing report.
- WHAT was done is already known and there is amedment for FCOM about that (no indication of reverse deployment - immediately put RCL to OFF).
- WHY that was done is still unclear.

The nature of the damage - the fuselage splitting into 3 pieces - looks to me like it was caused by vertical forces, during the bumpy ride down the hill into the ditch, as opposed to the airplane slamming into something head on.

There will be a quick and dirty summary of the accident sent to the operators which someone will hopefully leak, once Russia is open for business again.

vovachan, did you bother to look at the video?

PS:

Looking at the cockpit it is clear it was crushed from below -- probably when it crested the side of the hwy and broke off
http://gdb.voanews.eu/42073555-C5D5-...0_cy10_cw0.jpg

I would not rule out some NU prior to impact with the downslope, perhaps due some lift from the wings. With tail impact, the nose would have dropped with force, and rebounded, perhaps allowing the front of the aircraft to 'hurdle' up and plant the fuselage pointing upward, rather than collapsing at impact directly into the roadway.

All guesses, but the general discussion is a good one.

Hotel Tango, suspect Vovachan has been watching all this with great interest from the beginning, as most of us have.

I think most of us are wondering at the dynamics of the sled ride down the several levels of embankment and how speed influenced the final outcome. Several posters' studied comments indicate a speed of less than 80 knots, which might be suggestive of the nosewheel hitting, in quick succession, descending levels of embankment and exerting an upward moment before finally breaking the fuselage just above or just behind the nose gear. That might help to explain the main fuselage coming to rest pointing up - or it could be that, once the nose had broken off, the new aft CG was sufficient to accomplish an upward slant; the motorway clip focusses on the cars and highway debris and doesn't show how the fuselage reacted.

The bottom-upwards compression of the nose section itself: as the fuselage fractured, one can imagine it being leveraged nose-up as the fuselage cracked, just prior to hitting the final wall. Whether survivable or not, Kulverstuka's photos of stowed shoulder straps make you want to cry.

Another view - from inside the ditch, showing the up slope is not steep at all so there is not much for the airplane to hit frontally, except the guard rail.

http://radiovesti.ru/idb/320x240//a1/b_723126.jpg

Metaphorically, an uppercut to the chin can knock you out as fast as a punch on the nose. Vertical or horizontal, the force was....enough.

Converging speed
 

Machinbird,

That's a good point... the aircraft is indeed moving to the left in the camera field of view. However, the "fixed position in the camera" argument only applies when the relative distance between the closing objects is much larger than their closest separation.

The aircraft hits the edge of the roadway over 3 seconds ahead of when the car passes the same spot, having been visible previously for only 2 seconds, so I don't think that argument applies here.

Assuming these time gaps, and a 20-degree field of view for the camera, I get a plane speed is about 0.65x the car speed.

According to Google Earth the lampposts are 40m apart.
The car covers 4 gaps in about 7 seconds, so travels at 23+-5 m/s, about 45 knots.

That would make the plane speed then only 30 knots, which seems low, but about the same as the well-determined speed of the wheel, which is still plausible.

Edited - well, given MAK now say 190kph off the end, I must have been counting the grossly wrong bit of the aircraft past a mark.

Interesting to evaluate the swath of cut down lights/localizer/fencing/towers, marks on the downhill side, gouge entering the lowest canal, and significant compression damage prior to fuselage separation:

http://i337.photobucket.com/albums/n...ps41f62e5c.jpg

http://i337.photobucket.com/albums/n...ps449fe295.jpg

http://i337.photobucket.com/albums/n...ps618b2565.jpg

http://i337.photobucket.com/albums/n...ps58f6698c.jpg

http://i337.photobucket.com/albums/n...ps6fc91e7e.jpg

Stills from the dash cam video give an idea of the aircraft inclination as it struck the roadway bank:

http://i337.photobucket.com/albums/n...ps185d3b48.jpg

http://i337.photobucket.com/albums/n...pse95cf17c.jpg

http://i337.photobucket.com/albums/n...psb2a6e407.jpg

A full second later:

http://i337.photobucket.com/albums/n...psf6a92c45.jpg

(forumavia)
Photo made at VARZ (AviaRepair)

http://img-fotki.yandex.ru/get/5642/...474adc_XXL.jpg

©

This "fresh" Kommersantъ article more looks like compilation from two main russian aviaforums posts than like news from informed sources.

Sorry, could only read the google translate version, thought it was new info...

Alas, nothing in this article that was not mentioned/discussed in this thread. Nothing that we can take as "confirmed facts, not leaks" also (landing speed, CVR/FDR readouts etc.)

Of course - if the vertical force was strong enough to snap an airplane it can't be good for your spine.

Prior to Machaca's three catches, the a/c was well right of the roadway, and still in the :23 stamp. Of more interest would be all the :23 catches, for reference' sake. It is assumed by the damage that the zone of the last 100 meters has seen rapid decel. (any still that shares a time stamp with another is the same catch, until deciphered in the camera?) "A full second later" not necessarily....

Still looking for wheel tracks on the apron above the terraced drop off.

I see the locals are preserving the scene by parking heavy trucks on it....

For the four years I have been posting here, Machaca has been responsible for supplying exquisite photography of all kinds...

Many thanks to you, Sir.....:ok: