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-   -   A Sukhoi superjet 100 is missing (https://www.pprune.org/rumours-news/484925-sukhoi-superjet-100-missing.html)

pattern_is_full 15th May 2012 02:42

Although we are all still speculating in the absence of perfect data:

mcgyvr81's graphic makes the most sense to me in correlating to the scene photographs (notably post #98), which show a second ridgeline in the background beyond the ridge the plane actually hit.

Crash site - purple circle
Photo direction - straight purple arrow
secondary ridge - the right-hand yellow star

Why the plane ended up at the crash location (wherever it may be) is the important question.

Loerie 15th May 2012 02:44

Accident in Indonesia
 
Some kind of initial definitive report,once the FDR`s are recovered,would useful.
I cannot see,given the info that have,that this is an aircraft malfunction.....very interesting.....let`s see where it goes.
Looks like CFIT to me...

Loose rivets 15th May 2012 03:29


mcgyvr81's
excellent diagram and indeed, post, fits in frighteningly well with what I was trying to say.

If they had pulled the aircraft onto heading fairly tight in, that could have left as little as three miles to the point of impact. You can imagine the timeline and indeed the thought processes, as it became apparent there were walls on both sides.

WanganuiLad 15th May 2012 04:31

Were there walls they could even see ?
Yet to see good description of actual local cloud cover.

Is there any thoughts on why they were cleared to descend to 6,000 ?

dash8flyer 15th May 2012 05:04

That proposed flight path a few posts ago is very interesting... I think wondering about the cloud cover could become a valid point here...assuming they were circling the mountain, I can't help but think perhaps they turned too soon, thinking they were heading for the clear area to the south...
Is it possible the combination of obscuring cloud cover and perhaps unfamiliarity with the local area conspire against them and they got caught in a box area of rising terrain when they perhaps thought they were heading for the clear? They would more than likely have had precious little time to react to the rising terrain...

All pure and utter speculation from me here, and I most certainly do not profess otherwise..but while I was looking at the photo with the proposed flight paths, I just couldn't help but think they may have thought they had circled the mountain when in fact they were only half way around...

Just a thought from a first time poster...

mcgyvr81 15th May 2012 05:29

METARs suggest that weather conditions were deteriorating when the accident occured. Around sunset (~4 hours later), rain was reported in the area.

Under these conditions, it is not uncommon for large amounts of clouds & mist to build up along mountainsides within minutes (especially in a densely wooded area that is able to contain lots of moisture). Such highly terrain dependent weather phenomenae can hardly be reflected in METARs or the like.

To date, we can only speculate if the eastern slope of the "canyon" they entered was hidden/covered by some local weather phenomenon, therefore leading to misjudgement of position and heading.

Another possibility could be distraction ("VIP in cockpit").


As soon as FDR & CVR data is read out, we will know... hopefully. :bored:

PJ2 15th May 2012 06:16


Another possibility could be distraction ("VIP in cockpit").
I agree - while interpreting Dolya's wonderful photographic journal, clearly it was a lively and exciting environment, but also for those who do this work as a profession, there is recognized the high potential for distraction from the primary task of planning the flight, tending to disciplined operations and flying the airplane. In such an atmosphere, cockpit visitors, especially those which are perceived to have "high importance", one's mind may not be fully focussed "forward", and the pressure to "demonstrate" rather than merely just fly the airplane, is, in all likelihood, higher.

In combination with the weather, ("METARs suggest that weather conditions were deteriorating when the accident occured. Around sunset (~4 hours later), rain was reported in the area."), this could be seen as a high-risk operation, the perception of which may have been over-shadowed by the excitement and fun-atmosphere of the ongoing series of flights and the meetings with high-level officials.

sledge1984 15th May 2012 07:48

Hello everyone,

I tried to do a datum transformation. Topographic maps in Indonesia published prior to 1996 use the Indonesian Datum 1974. Taking the crash location coordinates (from the Sergey Dolya pictures) and transforming the coordinates into WGS84 (the GoogleEarth Datum) gives you 6°42'37.04'' S and 106°44'42.09''E as new crash coordinates.
I hope this helps.

Kulverstukas 15th May 2012 10:49

http://p.twimg.com/AsxeiS3CAAEcdZT.jpg:large

RetiredF4 15th May 2012 11:21


Loose rivets

mcgyvr81's excellent diagram and indeed, post, fits in frighteningly well with what I was trying to say.

If they had pulled the aircraft onto heading fairly tight in, that could have left as little as three miles to the point of impact. You can imagine the timeline and indeed the thought processes, as it became apparent there were walls on both sides.
Further speculation:
If they requested the descent for sightseeing in that area, there is also a great possibility that flying into that canyon was part of the intention. To circle a mountain only enjoys one part of the cabin, whereas the other part is looking at blue sky. The crew might have thought to be qualified for such a stunt (test pilots), the aircraft was light (short hop, no luggage, only half passenger load, probably not fully fueled) and lots of cameras for nice pictures on board.

When flying visual in such a valley, the rise of the floor and the therefore asociated climbrate is not noticed very well. As the obstacles are close, all senses are tuned to the outside of the cockpit, not recognizing the decreasing energy state, until it is too late and the terrain outclimbs the performance of the aircraft. The electronic gadgets (TWAS) would be turned of anyway if intentional flying that close to the ground was intended.

There is a great possibility that it was sightseeing, as a turn around this mountain in that altitude is not part of any kind of IFR procedure.

Aviaton is full of show-off accidents, therefore this speculation is not out of the world.

tapdrum 15th May 2012 11:51

Try to translate some alt/long information posted by Kulverstukas:
Tidak bisa landing = could not land
Team II paskhas Prt.Tanjung (Posisi terakhir) = Team II Special Force (lead by) Prt.Tanjung( last position)
Team I paskhas (mayor Tambunan )= Team I Special Force (lead by) mayor Tambunan
Posko Cijeruk = Cijeruk command center
Helly Pad = Helipad
Lap. bola Cimelati = Cimelati soccer field

misd-agin 15th May 2012 14:08

RetiredF4 - :ok: :D

deSitter 15th May 2012 14:42

RetiredF4, a sobering thought and entirely reasonable.

Note that this particular mountain has the typical amphitheater-type caldera of a stratocone that has blown its top at some time in the past - e.g. Mt. St. Helens. Could they have misunderstood their aviation charts? Don't you guys carry topographic charts as well, as a matter of course?

It's possible that they misinterpreted the intersection of a low-hanging and thick cloud-deck, and the mountain flank, with the ridge line. They may have never seen or known what they hit.

stepwilk 15th May 2012 15:02

I suppose it's possible that the Sukhoi would be carrying a couple of whatever the Indonesian equivalents of VFR sectionals are--would be a good idea if they were planning to make low-altitude sightseeing flights--but typically, an aircraft of this category would use only IFR en route and high-altitude charts, where topography is irrelevant because minimum-safe and en-route altitudes would guarantee substantial ground clearance. Plus, assumedly, ATC during approaches and departures. During normal operations of any transport-category or business-jet aircraft (the only turbines I've flown), "topographic charts" would not be aboard.

PJ2 15th May 2012 15:05

sledge1984;

The "Dolya" coordinates and the WSG84-corrected coodinates are not that far apart:

http://www.smugmug.com/photos/i-gXR3...gXR32hj-XL.jpg

gums 15th May 2012 16:27

This reminds me of the demo 'bus crash when the senior pilot got real low and the flight controls limited his pull-up and the motors didn't spool up real quickly and.......

There's a time to show off the capabilities of the jet and such, but not with 40 SLF's along and in marginal weather while in mountainous terrain. Sheesh.

The CVR will show more than the FDR, IMHO. We may learn what the decision process was, and the impact point and flight path will only show the raw stats.

My buddy flew into a mountain near Cali about 16 years ago after turning back from a flawed FMS setting concerning the radio beacons and waypoints. Unfortunately, the turn was too wide to reach the intended waypoint and they kept descending with terrain ahead. BAM!! I honestly believe he had a better chance of avoiding impact than these guys. Almost made it and it wasn't a vertical cliff. A few survivors, as well.

Road_Hog 15th May 2012 16:57


Originally Posted by Wanganuilad
Is there any thoughts on why they were cleared to descend to 6,000?

Worth a read.

http://gerryairways.********.co.uk/2...ut-deadly.html

Forum doesn't seem to like the link. You'll have to copy and paste the link below, do not click on it as it doesn't work.

http://gerryairways.blogspot.co.uk/2012/05/ssj-100-descent-innocent-but-deadly.html

Annex14 15th May 2012 18:12

Link
 
Road_Hog
Thanks for that link. What that report contains is in my opinion ONE of several possible explanations to what really happened. At least it shows logics of routine flying procedures.
I had before, because of all the different posts, looked in the same direction as
mcgyvr81 and RetiredF4. It seemed to obvious that something went wrong on a "demonstration flight" - just like choosing the "wrong valley". However I did have problems to get those pictures of the crash site, the coordinates published and those visible on the "rescue centre" pictures and the GE and GM facts in line.
I think, since the FDR and CVR are reported to be found, it will not take too long untill more facts become known.

Kulverstukas 15th May 2012 19:07

http://img.antaranews.com/new/2012/0...-Sukhoi-15.jpg

lomapaseo 15th May 2012 20:21

Kulverstukas

Oh Oh

I prefer bright orange unopened


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