CRJ down in Sweden

[172_driver]

In the early hours local radio is reporting freight plane between Oslo and Tromsö has come down in northern Sweden. A crash site has been located. Swedish registered a/c. Is Westair still flying freight in Norway with CRJs? Could be way off, not so familiar with who his doing what these days.

[FLEXJET]

A CRJ-200

Plane crashed in northern Sweden after issuing a distress call | Stuff.co.nz (http://www.stuff.co.nz/world/europe/75738465/plane-crashed-in-northern-sweden-after-issuing-a-distress-call)

https://twitter.com/flightradar24/status/685300016693534720/photo/1

Svenskt postflyg störtat i fjällen | Nyheter | Aftonbladet (http://www.aftonbladet.se/nyheter/article22055186.ab)

[9 lives]

What a harsh location for trouble! A friend and I flew it last summer, magnificent beauty, but not somewhere you want to have to put down! While thinking of the crew, think of the job ahead for the search and rescue crews too...

[NiclasB]

Crash site located on a mountain plateau by Norwegian Air Force F-16 between northwest corner of Lake Akkajaure (in Sweden) and the Norwegian border. "It is an obvious crash site with a diameter of 50 meters." says Daniel Lindblad, an official spokesperson for the Swedish Sjöräddningen (SAR).
Norskt postplan störtade i Sverige | Västerbottens-Kuriren (http://www.vk.se/1610984/norskt-postplan-stortade-i-sverige-2)

Looks like something dramatic happened. The LKP according to Flightradar24 is at FL330, there was a brief mayday, and then nothing. Let's hope the flight recorders survived.

The recovery operations may be difficult since it is mountainous terrain and the temperature is around -30C and predicted to remain so for a few days.

[RYFQB]

From local media (http://mobil.fremover.no/lokale-nyheter/fly/flyulykker/fly-fra-oslo-til-tromso-har-styrtet/s/5-17-108393) in Norway:
- Aircraft lost altitude very quickly
- Crash site 9 km from Norwegian border
- 15 by 20 m crater, wreckage within 50 m radius, no large pieces
- Spanish and French crew
- Mayday just before 23:30z picked up at BOO
- Crash site found at 02:15z by RNoAF F16
- No longer a rescue mission

I'll add it's cold in the area, below -30C this morning. This is only about 60 km (due west) from the RNoAF C130 crash (http://www.pprune.org/military-aviation/480037-norwegian-media-reporting-rnoaf-hercules-missing.html) at Mt. Kebnekaise a few years ago.

[RYFQB]

The aircraft departed Oslo on route to Tromsö and declared mayday at 23:31 whereby the Swedish and Norwegian search and rescue teams were notified. The crash site was located at 03:10 near the Norwegian border by the lake Akkajaure in the Swedish Lapplandsfjällen by air rescue services with support from Hovedredningssentralen in Norway.**

The search has been taken over by the Swedish police which are on their way to the accident site. The internal process is coordinated by the Company’s Emergency Response Team.

Route*
Flight no: SWN 294
Route: Oslo – Tromsö
Crew members on board: 2
Type of freight: General freight / Post

Aircraft*
Registration: SE-DUX
Aircraft Type: Bombardier CRJ200 PF
Year of manufacture: 1993
Manufacturer’s serial number: 7010
Hours flown since manufactured: 38 601:49
Total flight cycles since manufactured: 31 036

West Atlantic Sweden AB has operated the aircraft since 2007 and flown approximately 10*000 hours.

Crew*
Age: Captain 42, First Officer 34*
Employed with the company: 2011 and 2008
Flight hours: Captain 2 050 hours on type, total hours 3 173
First officer: 900 hours on type, total hours 3 050

Newsroom (http://www.westair.se/Newsroom/2016/01/08/SEDUX-Accident)

[readywhenreaching]

the aircraft was flying at FL330 along T65 route

jacdec.de (http://www.jacdec.de/2016/01/08/2016-01-08-west-air-canadair-crj-200-crashed-in-sweden/) has a story of it
http://www.jacdec.de/WP/wp-content/uploads/2016/01/2016-01-08_SE-DUX_CRJ2_Westair@Akkajaure_ACC1small.png (http://www.jacdec.de/2016/01/08/2016-01-08-west-air-canadair-crj-200-crashed-in-sweden/)

[ManaAdaSystem]

It will be interesting to see what they carried in the cargo holds.

[thomasfo]

That will take some time since it carried parcels from the Norwegian Postal service and you do not have to specify content when sending domestic parcels. Probably have to contact all the senders. Some of the senders may even be unknown for unregistered parcels.

[RYFQB]

Crash site at 1000 masl, aerial view from Swedish TV.
http://i64.tinypic.com/mrdyr.jpg
http://i68.tinypic.com/2s0n1j4.jpg
Poliskälla: ?Planet har störtat rätt ner i backen? - Nyheter | SVT.se (http://www.svt.se/nyheter/regionalt/norrbotten/poliskalla-planen-har-stortat-ratt-ner-i-backen)

[hoss183]

From the pictures, that went in near vertical, high-energy. Possible elevator/rudder failure?

[MrSnuggles]

From Dagens Nyheter, a Swedish paper.

Norskt postplan störtade i Sverige - DN.SE (http://www.dn.se/nyheter/sverige/norskt-postplan-stortade-i-sverige/)

Räddningsarbetet är besvärligt eftersom haveriplatsen bara kan nås via helikopter eller snöscooter.Postflyget, som flög på uppdrag av norska postverket, hade en last på fyra och ett halvt ton bestående av brev och paket. Enligt räddningsmanskapet, som var först på plats, totalförstördes planet vid det kraftiga nedslaget.


My translation:

Rescue work is hard because the accident site can be accessed only via helikopter or snow mobile.
The postal flight, flying on behalf of Norwegian Postal Service, was loaded with 4500 kgs of letters and parcels. According to the rescue team first accessing the site, the plane was completely destroyed by the impact.

[CaptainProp]

Unlikely to have anything to do with weather as the information provided here puts them at FL330 when they declared mayday.

CP

[MrSnuggles]

Information about the accident unfolding:

Räddningsledaren: ?De kunde inte göra någonting? | Nyheter | Aftonbladet (http://www.aftonbladet.se/nyheter/article22057289.ab)

Det har gått nedåt väldigt fort. Från 33 000 fot har de störtat i en hastighet av ungefär 9 000 fot i minuten.

My translation:
It has gone down really fast. From 33 000 feet they fell with a speed of about 9 000 feet per minute.

And also:

Planet har inte kraschat in i ett berg utan nedslagsplatsen indikerar att man störtat ned i backen med nosen först.
–Enligt svenska försvarets radar gjordes en svag högersväng innan kraschen men man har gått rakt ned. Kratern vid haveriplatsen är femton meter djup och tjugo meter bred. Det är ett väldigt stort hål, säger Anders Lännholm.


My translation:

The plane did not crash into a mountain, but the impact site indicates a nose down attitude.
- According to radar from the Army, they did a slight turn to the right before the crash, otherwise it was straight down. The impact crater is 15 metres deep and 20 metres wide. That is a very big hole, says Anders Lännholm. (Comment: Anders is SAR chief.)

[Nemrytter]

Unlikely to have anything to do with weather as the information provided here puts them at FL330 when they declared mayday.Clear skies and light winds at the time of the accident. Doubt weather has anything to do with this one.

[arabian rancher]

Maybe we shouldn't blame the crew, until we know what happened and probably not even then.
Night freight pilots tend not to amass hours as quickly as the rest of us, but they had five and eight years experience with the company presumably flying in the area.
It would seem that something catastrophic happened at High altitude and resulted in a near vertical impact. Quite likely a crew with twenty thousand hours each could have done nothing about it either.
RIP guys, and condolences to family and friends.

[4468]

sitting in the cruise for 5 hours at a time doesn't make you experienced
Very true.

Doesn't matter how many hours you have in your logbook, only the next one's important. If you train people sufficiently, they can have enough experience, even with very few hours. Look at Air Force pilots, flying Fast Jets. Cruising the airways is a discipline, but it ain't difficult!

If only 'experience' protected the 'experienced'?! But it doesn't does it!

[Viking101]

I think this might be West Atlantics first accident.

Thoughts to the crew members families, and to their colleagues too. This will be a tough time ahead.

Stay strong.

[Atlantic_Conveyor]

9000ft rate of descent is going some. A tangle with weather and stall? At FL330: probably not but then again, Air France managed it. Looks like an elevator failure to me, or maybe a trim runaway and break up. Three thousand hours each is plenty if the crews are decent, I don't believe that they were to blame. Now the plane. Must be elderly, or it wouldn't be flying freight. I'm sure the investigators will be all over the maintenance records. It's not just helicopters that hang by a bolt you know.

[Lancelot de boyles]

I worry, sometimes, at the responses that come from some ppruners. Often, they criticise the professionalism or qualifications of those unable to defend themselves, when in reality, their response speaks more for their own lack of experience or professionalism.
Why are some people so hasty to damn others with so little information?


2 colleagues, whom some of us may have met, and many have not, are no longer with us. This should be a moment of reflection for every single one of us. There are likely less than a handful of people at this time who know anything of what happened, and two of them can no longer tell us.

As for experience, and first job?
2 pilots who have each about 3000hrs, and between 4 and 7 years flying experience in freight Ops, with their company. In other branches of commercial flying, they would likely have between 4000 and 6000 hrs total time each. It has already been mentioned that the nature of our business tends to mean lower hours with similar number of sectors when compared to our peers.
I would be inclined to suggest that these two colleagues are more likely to be quite well experienced, when compared to others.
Sadly, aviation is rather blunt in its understanding of people's qualities; never mind the quality, feel the width! Unfortunately, Hours count higher than all other aspects of experience, which is a very sloppy approach to assessing a person's ability. A trap that a number of our 'colleagues' have already fallen into within this thread.
Is this a sort of keyboard Tourette's? Take a moment before hitting enter.

The facts are few at this time, but speculation is rife. However, there is probably scope for very informative discussion, without trashing people that we hardly know.

[Pali]

Crash site found at 02:15z by RNoAF F16

I am bit surprised - at 2:15z it must have been completely dark, even Moon didn't help much. F-16 is a fast jet so my respect to the pilot who can find such a small trace at night. After crash fire maybe?

[TWT]

Infra-red detection on the F-16 perhaps ? Crash site would have been warmer than the surrounding snow after impact/fire ?

[RYFQB]

Yeah, they've got pretty impressive IR/night vision. Plus location is probably almost exactly at last known radar contact? The first description of the site was also released well before daylight.

[RYFQB]

Video captured by the F16 has been released:
Norske F-16 fant flyet - se video fra havaristedet - NRK Nordland - Lokale nyheter, TV og radio (http://www.nrk.no/nordland/norske-f-16-fant-flyet---se-video-fra-havaristedet-1.12739279)

Helo at the scene is Norwegian Air Ambulance.

[k738]

Definitely too early to conclude with what happened. But as mentioned, the small crash area tells us that it was a nose down impact probably. T-tails(as the MD-80) have had problems with the jackscrew and the horizontal stabilizer earlier. This AC had 38 000 hours, and from 1993. Anybody know if the CRJ have any history with jackscrew fatigue?

[MrSnuggles]

Picture of the airplane in question, and a location.

http://gfx.nrk.no//SOwf0w-SW7Q7MgJXffikBgnIw9wNHNf6ARiioEE0AVPQ

This is above the Arctic Circle. Weather is probably -30C or more, most likely windy, making the chill really hard. This area has no roads due to the mountain terrain so you really need snow mobiles or helis to get there. The hours of daylight are very low, and the sun won't rise above the horizon at this latitude.

Another picture of the airplane, from Flightradar24 twitter:

https://pbs.twimg.com/media/CYLExVeWEAATpG7.jpg

[pattern_is_full]

Right off the top of my head, in 2 minutes I came up with 4 widely different scenarios that equally fit the known facts at this moment. Based on previous events with a similar profile - extreme dive from cruise altitude.

And I've probably missed a couple - aviation is pretty good at coming up with "new" holes in the cheese,, that we've never run across before.

I don't list them, because someone is sure to start "fixating" on one or the other - with 80%+ odds of being wrong. Which is a poor way to maintain credibility.

I expect additional information will be forthcoming, which will eliminate some of those scenarios, and point more strongly to others.

[MATELO]

I hope they can recover the data from the CVR & FDR. It looks some impact that. :sad:

[peekay4]

That the crew were able to get out a (brief) mayday call eliminates certain scenarios too.

[UV]

Regrettably PPRUNE at its very worst again. Maybe the mods will take a look at the Flyer forums where the Top Man closed the last two fatal accident threads due to this sort of inappropriate garbage.

[tdracer]

I hope they can recover the data from the CVR & FDR. It looks some impact that. :sad:
My thoughts as well - that looks more like a meteor crater than an aircraft crash. Twenty year old recorders might not be up to it :uhoh:

[Mad (Flt) Scientist]

While 9000fpm is fast its not THAT fast (its less than 100knots), and doesn't seem to be consistent with the speed of impact implied by the photos of the crash site. Since the crash site photo is "real" and the 9000fpm is a report and subject to being wrong for various reasons, based on the VERY limited info we have now i might be tempted to suggest they came down a LOT faster than that...

[Machinbird]

While 9000fpm is fast its not THAT fast (its less than 100knots), and doesn't seem to be consistent with the speed of impact implied by the photos of the crash site. Since the crash site photo is "real" and the 9000fpm is a report and subject to being wrong for various reasons, based on the VERY limited info we have now i might be tempted to suggest they came down a LOT faster than that... I Agree
Looks to be closer to Mach 1 and 70 to 80 degrees ND.
Not pleasant to contemplate.

[atakacs]

Interresting IR imagery indeed. Looks like a very high speed almost vertical impact. As others have mentioned this might have far exceeded the flight recorder design envelope. A pretty strange and dramatic one.

[Nemrytter]

Since the crash site photo is "real" and the 9000fpm is a report and subject to being wrong for various reasons, based on the VERY limited info we have now i might be tempted to suggest they came down a LOT faster than that...The maximum rate of descent was closer to 30,000fpm.

[tubby linton]

If the figures quoted above are to be believed then my initial thought is an accident similar to this.
https://en.m.wikipedia.org/wiki/Alaska_Airlines_Flight_261

[B-757]

As an ex. 200 pilot, an incident that a colleague had, comes to mind..Thrust reverser cowl separated from the engine in flight, and hit the tail on the way out..Damage, but landed safely..


We do not know what happened to this aircraft, but they will find out..
My deepest sympathies to the friends and families..


Fly Safe..

[skyship007]

Looks like the ultimate vertical impact as the scatter is symmetrical. I doubt very much that this was any type of pilot error or bad weather. The big first two questions are, are the FDR and CVR readable and is there any sign of some part of the tail in a different location to the impact site??

[barit1]

Locating the "four corners" of the accident will be a first priority, to determine inflight breakup possibility.

[MrSnuggles]

Parts of the black boxes have been found!

What parts, are not specified, but it seems they too were smashed to smithereens in the crash.

Delar av svarta lådan hittad - Nyheter | SVT.se (http://www.svt.se/nyheter/regionalt/norrbotten/delar-av-svarta-ladan-hittad)

Vi har hittat vissa delar men inte kompletta enheter. Det kommer att ta dagar att hitta dem, säger Nicolas Seger.Målsättningen är att vara klar med utredningen inom tolv månader, säger Nicolas Seger.My translation:

We have found certain parts but no complete units. It will take days to find them, says Nicolas Seger.

The goal is to finish the investigation within twelve months, says Nicolas Seger.

(Comment: Nicolas Seger is heading the investigation for Haverikommissionen, the Swedish equivalent to AAIB/NTSB/BEA)

[The Ancient Geek]

FWIW
The contents of the mayday call they reportedly made should have given the investigation team some early clues.

[er340790]

I was struck by the similarities with the relatively small but deep impact craters left by those 1990s 737 rudder-hard-overs and the Flight 93 757 that crashed at Shanksville on 9/11.

Apparently the total obliteration of the aircraft is not just due to the speed and angle of impact. As the aircraft noses deeper, the rear sections are met by rebounding shattered wreckage from the front of the aircraft, blasting back out of the crater, the combination of these forces is what practically pulverizes all material.

Any parts located are going to be small. Very small. Black boxes included.

[Tu.114]

However, on the Germanwings crash site in the Alps, both the recorders were found mostly readable. This was a rather high energy impact as well.

[merkurius]

This is an open question to all operating crj pilots how to recover elevator runaway trim on high level cruise?

All my thoughts to the involved familys. RIP

[MrSnuggles]

Information from Haverikommissionen (SHK), the Swedish equivalent to AAIB/NTSB/BEA. This link will be updated as the information comes in:

Utredningar - Olycka i Lappland med flygplanet SE-DUX av typen Canadair CRJ 200 (http://www.havkom.se/utredningar/civil-luftfart/olycka-i-lappland-med-flygplanet-se-dux-av-typen-canadair-crj-200)

Under lördagen har den ena av de svarta lådorna (FDR) hittats. Den är kraftigt demolerad och SHK:s tekniska utredare arbetar med att undersöka om minnesenheten är intakt. Enheten kommer därefter att transporteras till ett laboratorium där informationen kan läsas ut. Det kan ta någon vecka innan detta är gjort.
Delar av den andra svarta lådan (CVR) har också hittats. Den enheten är däremot inte intakt och den del som innehåller minnesfunktioner har ännu inte hittats. Arbetet med att hitta återstående delar kommer att fortsätta.


My translation:

During Saturday, one of the black boxes (FDR) has been found. It is seriously damaged and the technical investigators at SHK are working to find out if the memory unit is complete. The unit will after that be transported to a laboratory to read the information. This could take another week.
Parts of the other black box (CVR) has also been found. That one is not complete and the part containing the memory module has not yet been retrieved. Work to find remaining parts will continue.

[cappt]

This is an open question to all operating crj pilots how to recover elevator runaway trim on high level cruise?

All my thoughts to the involved familys. RIP

(1) Control wheel ....Assume manual control and override runaway.
(2) Both stab trim disc... Press, hold, and release.

There's more but these are the first steps.

[MrSnuggles]

I have not heard nor seen any reference as to what was said in the mayday call. I'd really like to know. Will update as soon as I find out.

This is a very strange crash, not many planes have accomplished such an obliteration, the biggest pieces are around 50cm diam so far. It was a very nose down attitude.

Rescue teams pumped about 200kgs of jet fuel from the hole made by the plane.

It seems like the whole plane is accounted for, nothing indicates that something (wing/elevator/etc) fell off the plane. The hole is not yet explored though, hopefully new information will emerge tomorrow, Sunday, when they will try to dig. There are obstacles for the snow mobiles so the only way in and out is via helicopter so everything has to be flown in. Weather is still -20C or worse, winds are varying so add a good amount of wind chill to that. Good thing is that it has not been snowing so everything is smooth working.

[AAKEE]

For the mayday call, it said somewhere in media that it was just the mayday, without ny further information in the transmission. Of, corse, media isn't that reliable at all times. I'll see if I can find a link.

[skadi]

Both memory modules of CVR and FDR were found saturday resp. sunday

Investigations - Accident in the arctic north of Sweden to a Canadair CRJ 200 aircraft (SE-DUX) (http://www.havkom.se/en/investigations/civil-luftfart/olycka-i-lappland-med-flygplanet-se-dux-av-typen-canadair-crj-200)

skadi

[valkyrie42]

..........And sadly human remains may they RIP

Se NRK:s unika bilder från olycksplatsen - Nyheter | SVT.se (http://www.svt.se/nyheter/regionalt/norrbotten/se-nrk-s-unika-bilder-fran-olycksplatsen)

[Yankee Whisky]

Quote;"(1) Control wheel ....Assume manual control and override runaway.
(2) Both stab trim disc... Press, hold, and release.

There's more but these are the first steps. "




(Manual control) At any speed ? Including cruise ...................

[Machinbird]

(Manual control) At any speed ? Including cruise ................... I think he means direct human control instead of through the autopilot. Not un-boosted elevator control (If that is even possible in a CRJ).

For those postulating complete loss of the HS scenarios, you can probably discount that accident chain. Yes, the aircraft would pitch nose down initially, but it would continue pitching, much like the Metrojet crash, and the impact would be with much lower energy.

With any high speed departure of a THS equipped aircraft from level flight, Mach-tuck could make it harder to recover and would probably require judicious use of HS trim if it got into that range-but that is all theoretical test pilot stuff. There is also the Hoot Gibson maneuver that can be used to shave off unwanted speed. (Dropping the Gear) Results not guaranteed.

[Mad (Flt) Scientist]

I think he means direct human control instead of through the autopilot. Not un-boosted elevator control (If that is even possible in a CRJ).

CRJ elevators are fully hydraulic, multiple actuators per surface, no manual reversion at all. So yes, "manual control" in this context means "hands on the controls".

[cappt]

Yes any speed.
When you say elevator runaway on the CRJ it is actually a stabilizer trim runaway as that is what is trimmed for flight.
The CRJ has a movable horizontal tail in which the entire horizontal stab is trimmed as needed for flight. The Elevators attached to the rear of the stab can overcome a runaway trim situation. The elevators and rudder are powered by all 3 hydraulic systems (1,2,3). Three PCU actuators (1,2,3) are on each the rudder and elevator. In the event of one bad PCU actuator the other two will overpower the bad one.

[zac21]

Could somebody please explain how is it possible that jet fuel could be 'pumped out of the crater' after such impact ?
I find it extremely hard to believe that either 200 litres or 200 KG of jet A1 could remain :confused::confused::confused:

[Machinbird]

Could somebody please explain how is it possible that jet fuel could be 'pumped out of the crater' after such impact ?I'll try,
The best explanation has to do with the fact that there was very little horizontal velocity at impact and that some wreckage undoubtedly remained in the crater. Being a liquid, the fuel could lodge itself along the earth/snow at the sides of the crater and not be ejected by the rebounding earth and wreckage in the center of the crater. Later, it would drain downward and collect at the bottom. It appears to have been a very small fraction of the fuel load.

I once investigated another crash where the aircraft impacted nose down & wing down with some horizontal velocity. There the fuel load washed the fragmented wreckage out of the crater and distributed it systematically along the horizontal velocity vector.

[zac21]

Thanks Mach,, but I still find it hard to believe " anything was remaining "

[TwoStep]

The Swedish investigators say 1.5 cubic meters of liquid, mostly jet fuel was recovered. Isn't that 1,500 liters, not 200.

Investigations - Accident in the arctic north of Sweden to a Canadair CRJ 200 aircraft (SE-DUX) (http://www.havkom.se/en/investigations/civil-luftfart/olycka-i-lappland-med-flygplanet-se-dux-av-typen-canadair-crj-200)

[Smott999]

Similarities perhaps with the Conti Express 2574 in Texas 1991?

Believe they lost a leading edge of the HS resulting in abrupt unrecoverable nose down....

[Petercwelch]

Can we assume that a problem with cargo e.g. Fire would have happened more gradually and not resulted in such a brief message and descent?

[PPL Hobbyist]

CRJ elevators are fully hydraulic, multiple actuators per surface, no manual reversion at all. So yes, "manual control" in this context means "hands on the controls". Although the flight surfaces on the CRJ are hydraulically actuated, there is no computer in between the pedals and the control column deciding weather the crew are flying safely or not and maybe just making matters worse such as on other FBW aircraft I know. So the flight surfaces should have done exactly as commanded.

What are the chances of a scenario like UA232?

[lomapaseo]

possibly any water at the bottom of the crater mixed with residual jet fuel. Thus they had to pump out the mixture before working to retrieve important bits. Nothing significant about this

[pattern_is_full]

Can we assume that a problem with cargo e.g. Fire.....

Never "assume."

cf: https://en.wikipedia.org/wiki/Confirmation_bias

[Machinbird]

Although the flight surfaces on the CRJ are hydraulically actuated, there is no computer in between the pedals and the control column deciding weather the crew are flying safely or not and maybe just making matters worse such as on other FBW aircraft I know. So the flight surfaces should have done exactly as commanded.Assuming that the linkage was not jammed by a foreign object such as a tool or frozen water/deicing fluid.

[Mad (Flt) Scientist]

Assuming that the linkage was not jammed by a foreign object such as a tool or frozen water/deicing fluid.
Concur.

Or the AP was not engaged, as thats a 'computer' with a degree of authority over the flight controls. Or the stall protection COMPUTER didnt decide to do something. Or the Horizontal STabilizer Control Unit, likewise.

The number of aircraft where there isnt a computer of some kind involved nowadays is pretty small ....

[M609]

Swedish AIBN wil have to wait for summer for any further recovery attempts.

NRK: Will have to wait until the ground thaws (Google translate) (https://translate.google.com/translate?sl=no&tl=en&js=y&prev=_t&hl=no&ie=UTF-8&u=http%3A%2F%2Fwww.nrk.no%2Fnordland%2Fpostflystyrten-i-sverige_-_-vi-ma-vente-til-bakken-tiner-1.12744225&edit-text=&act=url)

[_Phoenix]

It think the crash site is about at right distance for descent initiation.
Is it possible cargo shifted forward once aircraft pitched down?

[ika]

It think the crash site is about at right distance for descent initiation.
Is it possible cargo shifted forward once aircraft pitched down?

I believe a CRJ 200 is highly sensitive to load distribution but I'm sceptical it could be loaded with a c of g so far forward that elevator control became impossible. Bear in mind that at forward C of G limit there is enough elevator authority to rotate or flare the aircraft at takeoff or landing speeds and in the cruise the elevator will have dramatically more authority (forces proportional to square of speed, subject to actuator/structural limits and altitude density effects). It was apparently carrying mail. Unless there was a cartoon lead ball, which didn't roll backwards under acceleration and pitch up on takeoff, it seems unlikely. But someone with a CRJ load schedule can probably determine a realistically bad load distribution and corresponding moment and comment...

[darkbarly]

in the cruise the elevator will have dramatically more authority (forces proportional to square of speed, subject to actuator/structural limits and altitude density effects)

In other words you mean less elevator authority ika? Low IAS at cruise level methinks.:ooh:

[Sorry Dog]

If the V/S reports are close to accurate then it seems inconsistent with a prolonged stall condition similar to other recent mishaps. The V/S seems just a bit too high... if we have 9000fpm then thats around 79kts and assuming a 45 degree path vector with forward speed of 9000 as well that gives us an aircraft speed of 111 knots. Now the IAS at higher altitude may be in stall territory but as they got down to lower levels then there should have been enough speed to give enough control authority to correct without losing more than a few thousand feet or less.
That is until you start considering other factors such as spatial disorientation and other human factors that have led to loss of control in other accidents.

One other CRJ crash I'm thinking about is the one where a couple of pilots on repositioning flight decided to try their hand at being test pilots and flew themselves right off the backside of the power curve, stalled the wing, cooked the turbines, and were never able to restart, and then ran out of altitude to make a runway. Yet there are still more differences than similarities here as the final impact in this crash seems much different as well the crew seeming to have a more catastrophic problem since they didn't have time to get more than a single mayday off.

Considering the location, there is a lot riding on getting the recovered memory modules to reveal their secrets.

[Tourist]

That hole is not a stalled aircraft hole.

That is a very high speed near vertical hole.

[pattern_is_full]

The contents of the mayday call they reportedly made should have given the investigation team some early clues.

AH reports today:

On Jan 12th 2016 the SHK told The Aviation Herald that the distress call just contained the repeated words "Mayday", there was no further information in the call.

[tdracer]

AH reports today:

I sure hope they can get useable data from the recorders - if not it's going to really hard to determine much from what little is left of the aircraft :sad:

[ika]

In other words you mean less elevator authority ika? Low IAS at cruise level methinks.:ooh:

What sorry dog said! Sorry for not being clearer; air may be thin and IAS not that high at 33,000 feet but pretty soon after you start diving earthwards IAS and control authority will go up. There's a general surmise (not conclusive) from the images and other data that it went in fast, nose-first, in one piece rather than a stall or in flight break-up. At some point, let's say 15,000 feet, assuming (for this only) pilots were not incapacitated or disoriented, heading nose down at a fair pace, if one had functioning controls one would expect to pull up as far as possible (and as necessary throttle back). I don't know about others but if controls worked but a forward c of g hindered pull up, faced with the grim choice of the certainty of what the looming ground means versus the possibility of overstressing the airframe I'd probably spend my last 60 seconds pulling hard back until either the nose stopped pointing at the ground or the elevator came off! Since they haven't located separate debris suggesting elevator detachment/damage it suggests to me that a c of g issue alone is unlikely. Some form of control issue, whether trim runaway, multiple hydraulic failure etc and/or a crew incapacitation issue must be considered, in my humble view. But feel free to disregard. I suspect most will agree, apart from the tragedy, is that it is both very curious and, unless the memory proves recoverable, unlikely we will know.

[tdracer]

Since they haven't located separate debris suggesting elevator detachment/damage it suggests to me that a c of g issue alone is unlikely.If part of the elevator (or tail) departed at high altitude, it could potentially be many miles from the (main) crash site. Given the remoteness of that whole area, such relatively small part(s) might not be located for months or even years.
I'd think that since they were able make a Mayday call, crew incapacitation would be unlikely, but as pattern_is_full noted, never 'assume' anything.

[FIRESYSOK]

Having flown this type for many, many years, I can say a HS failure/runaway was probably my biggest concern.

This is a quality-made airframe and engine combination, but the electronics/trim switch/elevator feel system left a lot to be desired.

[PrivtPilotRadarTech]

"The electronics/trim switch/elevator feel system left a lot to be desired."
Thanks, FIRESYSOK. Good to hear from someone with experience in the type.

[unworry]

There is also the Hoot Gibson maneuver that can be used to shave off unwanted speed. (Dropping the Gear)

@Machinbird

I'm glad you clarified ...

In my earlier days, the term was code for "erase the tapes" :suspect:

[AliTee]

Having flown both CRJ's and SE-DUX in its post cargo mod, I have to agree with the Stab Trim Runaway hypothesis. I haven't flown a 200 since 2011 but I know there was an SB or AW published after a couple of runaways in the U.S. a few years back. Whether DUX ever had it done will soon be revealed.
If I recall correctly the loads from OSL to TOS cubed out before they weighted out and were very well secured with a very simple system. In level flight or even in a normal 3 degree descent, the chance of trolleys coming loose was next to zero.

[Methersgate]

Re: post 78. Sometimes, someone posts something really good here. This is one of those times. Thank you.

[FIRESYSOK]

There is no manual trim wheel on this type either.

It's happened to me that both pitch trim channels failed at cruise speed and we were left with an uncomfortably out-of-trim airplane as we slowed for approach.

I can only imagine if a HS runaway were not disconnected early via disconnect switches or CB, what the elevator forces would be with no manual trim reversion to correct the problem.

[Machinbird]

I can only imagine if a HS runaway were not disconnected early via disconnect switches or CB, what the elevator forces would be with no manual trim reversion to correct the problem. I'm surprised that the aircraft would be certified without some means to recover to a good trim setting. If all you have is "Jack be nimble, Jack be quick, as a defense before it gets away from you, then that isn't too good. If you are flying on autopilot and the first you know of a problem is that the autopilot has been overpowered, and the aircraft is pitching down, then you are already too late. Even the relatively simple Douglas designed, THS equipped, A-4 Skyhawk had a pitch trim "crowbar" lever that let you manually overpower whatever signals were trying to move the pitch trim actuator screwjack.

Limited information I've seen on the CRJ indicates that there is probably a pitch trim force warning light before the actual A/P disconnect. Is that correct?

[Chronus]

It think the crash site is about at right distance for descent initiation.
Is it possible cargo shifted forward once aircraft pitched down?

Phoenix`s question is worthy of further consideration.

Flight was airborne at 23:10 and crashed at 00:18. I estimate distance to destination was approx 1000 miles, possibly duration of some 2hrs or so.
The crash site near Akkajaure Lake and Tipel (FIR Bdry) would be some 400 miles to run to destination.
I would have thought it early for TOD.

Am not familiar with route. Anyone familiar with the route may perhaps enlighten us further.

[172driver]

I estimate distance to destination was approx 1000 miles

604 nm according to Great Circle Mapper (http://www.gcmap.com/mapui?P=TOS-OSL&MS=wls&DU=nm)

[AliTee]

I have experienced it in the sim. It is violent and uncontrollable unless immediate action is taken. At low altitude it is fatal. The change in attitude is so sudden that if you don't have your wits about you, you forget to push the master disconnect and just pull on the yoke for dear life. I suspect that they may have had a runaway, were taken completely by surprise and didn't know what hit them. If I remember correctly, Stab Trim Runaway did not even have memory items until late 2000's. Can any old CRJ guys remember when this was changed in the QRH?

[AliTee]

The initial report leads one to believe that they were still at cruise altitude. No report of a request or clearance to descend. Descending normally from FL330 would only require about 120 NM (including decel). Additionally there is high terrain south of Tromso that keeps you at or above 5000ft until inside about 11 miles if landing Rwy 01 (~80% or more), so no, I don't think they were descending.

[khorton]

I'm surprised that the aircraft would be certified without some means to recover to a good trim setting. If all you have is "Jack be nimble, Jack be quick, as a defense before it gets away from you, then that isn't too good.

The CRJ trim system, by design, should detect un-commanded motion and shutdown. The problem referred to by some earlier posts is that there was a manufacturing defect at a supplier, and the circuit boards for the horizontal stab trim control unit (HSTCU) did not have the required conformal coating applied to the boards during manufacturing, which left the traces on the circuit boards exposed to the atmosphere. The result was that after many years in service, the traces on the boards could corrode, and the corrosion could bridge adjacent traces, creating circuits that weren't supposed to be there. This resulted effectively in a circuit diagram that differed from the design, creating paths for electricity to flow where it shouldn't, resulting in uncommanded trim motion.

It is well and good to have a perfect design, but you need to ensure the delivered product actually conforms to the design, or all the bright work of the designers is for naught.

This issue was covered by Transport Canada AD CF-2006-20 (http://ad.easa.europa.eu/blob/CF200620_R1_English.pdf/AD_CF-2006-20R1_1). This AD, among other things, required the installation of new HSTCU, with conformal coating on the circuit boards. The accident aircraft should have had the new HSTCU installed many years ago, so accident should not be directly related to this old issue.

[Machinbird]

The CRJ trim system, by design, should detect un-commanded motion and shutdown.Thanks khorton,
The AD indicates that there are disconnect switches on each control wheel and I have seen pictures indicating a red 'pitch disconnect' switch on the left side of the center console.

When the autopilot is engaged, it has authority to command pitch trim motion, doesn't it? This type trim in a mechanical control system is usually activated by force sensing systems in the control linkage. Is that the case on the CRJ?
If so, then jams in the pitch control system can probably cause trim runaways.

Important caveat. I know next to nothing about the specific design characteristics of the CRJ. It is just that this specific situation has resulted in trim runaways in a number of different types of aircraft. Is there a common link? Design engineers are clever people and they learn from past problems and come up with novel solutions. They may well have circumvented this type problem with their HSTCU design.

[_Phoenix]

Descending normally from FL330 would only require about 120 NM

... the crash site is about 125 NM out of Tromso
Great Circle Mapper (http://www.gcmap.com/mapui?P=67%b043%2758%22N++16%b053%2748%22E+-+++69%b040%2729%22N++18%b054%2747%22E&PM=b:star7%2b%25U&DU=nm&SG=400&SU=kts)

[khorton]

There are stabilizer trim disconnect buttons on each control wheel. The red "PITCH DISC" T handle on the left, front of the centre console is for jams in the control linkages in the pitch axis - it disconnects the linkage that connects the left and right control wheel in the pitch axis. If you pull that T handle, the left control wheel is connected only to the left elevator, and the right control wheel is connected only to the right elevator, allowing for continued control by one of the pilots after a jam in the pitch control system. A similar ROLL DISC handle on the right side of the centre console is used for jams in the roll axis control linkages.

The autopilot will command pitch trim to zero out any required elevator servo commands, after a short time delay (to prevent it from commanding trim in response to short duration elevator commands). The autopilot receives elevator position information, and I believe it would disconnect if the elevator position did not match the result expected from the amount of servo current, but I'm not completely certain of this.

[Machinbird]

The autopilot will command pitch trim to zero out any required elevator servo commands, after a short time delay (to prevent it from commanding trim in response to short duration elevator commands). The autopilot receives elevator position information, and I believe it would disconnect if the elevator position did not match the result expected from the amount of servo current, but I'm not completely certain of this. khorton
Thank you again for your helpful descriptions.
This implies that there must be both right and left elevator servo valves and that the linkages between the control columns and the elevator servo valves are duplicated, probably all the way back from the cockpit. Since each elevator side is actuated by 3 cylinders on 3 different hydraulic systems, the servo valves are either a single valve body with 3 sections or actually 3 separate valves on each elevator side. Followup signals would probably be by means of a linkage attached to the individual elevators which is then summed with the associated input linkage. Autopilot trim inputs would then be taken directly off the summing linkage per your description. Then the question arises, are autopilot trim inputs taken from both sides and compared or from just one side? Or have I run well off the track?:}

Those design engineers are clever fellows and often do the unexpected to achieve their goals. I tried to download system information from Scribd, however didn't find much of great use.

[khorton]

There are three separate hydraulic actuators for each elevator. The servo valve controls have jam-tolerant mechanisms, so a jam in one servo valve control will not cause the whole system to be jammed. I'm not sure how the servo valves receive their position feedback from the elevators.

There are pitch control runs from each control wheel back to the elevator servos - left control wheel connected to left elevator servos, and right control wheel connected to right elevator servos. The two control wheels are connected via the disconnect mechanism (actuated by the PITCH DISC T-handle).

The autopilot commands to the HS trim have their source in the autopilot servo torque that is commanded. If the servo torque required exceeds some threshold for a minimum time, then the autopilot sends a command to move the HS.

Studying the maintenance manual a bit more deeply, it looks like my earlier statement that the autopilot receives elevator position feedback was probably incorrect. I don't see any such input on the spaghetti diagram for the autopilot.

[Chronus]

[QUOTE=_Phoenix;9237934]... the crash site is about 125 NM out of Tromso
[url=http://www.gcmap.com/mapui?

TIPEL is 158.4 nm R-196 TRO. I would therefore agree with Phoenix that the likelihood of loss of control initiated with the descent from cruise level is probable.

[captplaystation]

It may be if the ATC transcript included a request for & clearance to . . descend. If not, well, I am guessing, as professional pilots, they didn't just start on down.

158 out is a bit early for a descent from F330.

[espenjoh]

mil radar data show that plane make a right turn to the east when desending.
LINK (http://www.nordlys.no/her-forandrer-flyet-bratt-kurs-for-det-styrter/s/5-34-347876)

[balaton]

Hi All,

Cl-604 incident (similar a/c systemwise).
https://www.gov.uk/aaib-reports/aar-1-2008-bombardier-cl600-2b16-challenger-604-vp-bjm-11-november-2005

Cheers

Tamas

[khorton]

Cl-604 incident (similar a/c systemwise).
https://www.gov.uk/aaib-reports/aar-...-november-2005

That incident was caused by corrosion on the horizontal stab trim control unit (HSTCU). There were several similar incidents, which triggered the AD (http://ad.easa.europa.eu/blob/CF200620_R1_English.pdf/AD_CF-2006-20R1_1) mentioned earlier in this thread. That AD required replacement of the HSTCU with ones that had a conformal coating on the circuit board, to prevent such corrosion. Thus this accident should not have been caused by the same problem.

[despegue]

Is there any info on the loadplan?

A loadshift forward when starting descend due to no or broken forward uplocks will make a Freighter going in an unrecoverable vertical dive.

[Livesinafield]

The laodshift theory doesn't work, the aircraft is loaded with mail trolleys, each bay is packed tight with trolleys that are strapped to the floor, then each compartment has a spider net close the compartment off

I do this kind of loading all the time and feel its much safer than carrying a bulk load of loose items or even containers, each trolley is a fairly light weight 80-110KG on average, if the load was not secure correctly im pretty sure some catastrophic would have happened on take off or in the climb

Just toadd that this loading is done with the FO as a supervisor instructing where to put each trolley so I would be very very surprised if it wasn't secured

[YOUNGBUCK]

I'm not type rated on the CRJ so don't jump at my vague information.

I've heard that looking thru the tech log pages there was a problem with the stab motor which had been replaced, perhaps that wasn't the fix. Descent and path down suggest problems with the tail.
Condolances to the families friends and colleagues.

[atakacs]

Any news about the FDR readability?

[RYFQB]

It was said yesterday (http://www.nrk.no/nordland/de-svarte-boksene-sendt-til-frankrike-for-analyse-1.12756334) (article in Norwegian) that the recorders were sent to France a week ago, that two Swedish investigators are currently in France, and that they are confident they will get something out of the recorders within in a week.

[pattern_is_full]

AH reports today (1/26) that both recorders have data, are readable, have been read, and a prelim report is expected within 1-2 weeks, following analysis.

[750XL]

Crash: West Atlantic Sweden CRJ2 near Akkajaure on Jan 8th 2016, lost height after emergency call (http://avherald.com/h?article=4920a18a&opt=0)

[ATC Watcher]

Heard rumors of a possible collision with a UAV. anyone has more info?

[captplaystation]

That would be, to put it mildly, slightly disquieting. . . . . . .

[cappt]

Heard rumors of a possible collision with a UAV. anyone has more info?

Well that's interesting, what else do you have?
I have to admit the thought crossed my mind but was quickly discredited as highly unlikely due to the remoteness of the area.
Let's hope the FDR has some useful information that will lead to probable cause and not more questions.

[ATC Watcher]

I do not have anything more than a rumor that "someone" apparently lost a UAV in the same area at the same time, but nothing confirmed , therefore I was fishing here.
Maybe I should have posted this on the military forum:suspect:
But seen the impact crater , it is doubtful physical evidence will be easily found before the snow melts or if at all, and unless spotted visually before by the crew,I do not think the CVR/FDR are going to help much to validate or invalidate that possibility..

[AAKEE]

The Swedish board of investigation said they managed to read out the CVR(I Think with help of BEA) and that efter that they have some ideas what happend. Nothing more said yet, they would analyze the FDR first.




I would'nt put that much to the rumour about UAV's.

[golfyankeesierra]

On the avherald.com link (http://avherald.com/h?article=4920a18a&opt=0) there is a readers comment section and someone calling himself "military" says he has "some inside track", FWIW:
By Military on Wednesday, Jan 27th 2016 14:29Z

I have some inside track. Rumours Are flying about pertaining to a mid air collision with a military aircraft or asset . Watch this space .....

[Melax]

Oh boy, I hope it's not another Night Ship 282 !! (FEDEX 208 feeder crash maybe due to collision with an unknown object)

NTSB: 'Collision With Unknown Object' Killed Mobile Pilot | Aero-News Network (http://www.aero-news.net/index.cfm?do=main.textpost&id=c8886b93-36c4-4dca-a0dc-a5f40806f6c8)

http://www.ntsb.gov/_layouts/ntsb.aviation/brief2.aspx?ev_id=20021029X05400&ntsbno=ATL03FA008&akey=1

'Red marks' confound accident investigators | News: Aviation International News (http://www.ainonline.com/aviation-news/2007-07-24/red-marks-confound-accident-investigators)

[Livesinafield]

Had never heard of that, but dam its spooky!

[Melax]

Yep, The craziest thing is his sister (If I remember well), a substantial amount of time after the accident on her own recovered more than 700lbs of debris, including the 3 propeller blades from the swamp ! :ugh:That says a lot about the investigators. She is is a 727 pilot, this accident is still a mystery. The pilot was a 9-11 Hero. Very sad.

[PrivtPilotRadarTech]

Thanks Melax, that "Night Ship 282" incident is an interesting read while we're waiting for info from the CRJ CVR/FDR. A mid-air seems unlikely in this case, but strange things happen like the ASG-29 glider vs. Hawker XP800 near Minden, Nevada. No fatalities, but you should see the photos of the Hawker.

[b1lanc]

Given the number of UAVs in the air and the altitudes they can operate at kind of reminds me of the late 40's and 50's in the US where a number of mid-airs occurred between military and civilian ac due to lack of coordination between the military and CAA. I hate to think of how many military, intelligence, homeland security, local police, state police units may be operating what at this point but I suspect coordination with commercial aviation authorities is not necessarily well established.

[PrivtPilotRadarTech]

Hughes Airwest Flight 706 midair with an F-4 happened in 1971. Thankfully they learned some lessons from it.

[AAKEE]

This accident happened virtually on the border between Sweden and Norway.
In Sweden, but airspace delegated to Norwegian ACC.


Air surveillance radar systems from both countries cover the area and pictures already released from this.


Nordlys - Her forandrer flyet brått kurs før det styrter (http://www.nordlys.no/her-forandrer-flyet-bratt-kurs-for-det-styrter/s/5-34-347876)


Anyone seeing more than one A/C ?


We might not be 100% sure that the picture is'nt modified but the source is norwegian and the airspace Swedish( from a military view).
If unknown A/C wasn't Swedish, the swedish interceptors would have been launched.
If it wasnt Norweigan, would Norway then edit the picture?


No, there was no other A/C around I say.

[Machinbird]

No, there was no other A/C around I say.That is a transponder based picture. What about a non-squawking machine?

[ATC Watcher]

AAKEE : I do not want to add to this UAV rumour, but the picture you posted is from a synthetic display where anything can be filtered out, specific SSR codes and even Primary returns.

What would be interesting to see is what the Swedish Military primary radar displays show. On the other hand a small ,slow moving and mostly composite UAV would not offer much returns.

[RYFQB]

1. That image in AAKEE's link was released by the Norwegian military.
2. This is the largest UAV in use by Norway: https://en.wikipedia.org/wiki/AeroVironment_RQ-11_Raven
3. This is the largest UAV in use by Sweden: https://en.wikipedia.org/wiki/AAI_RQ-7_Shadow

[grizzled]

The single screen shot image released (above) shows what appears to be the last secondary radar return. I say last because of both the time and the altitude displayed.

That fact that here is no other "correlated" secondary radar target in the vicinity on that screen shot means little with regard to:
a. what may have been showing immediately prior to the mayday and start of descent
b. any primary radar returns

grizz

[cappt]

http://theaviationist.com/2014/08/01/rc-135-violated-swedish-airspace/

There have been many cases of airspace violations in the region during the last few years. Pure speculation but if a state operated stealthy drone was transiting the area it's doubtful it would be talking to anyone other than the operator.
Lets hope this is not the case.

[Hotel Tango]

but if a state operated stealthy drone was transiting the area it's doubtful it would be talking to anyone other than the operator.

If state or military operated, the operator would have full access to information on the traffic occupying that airspace.

[CaptainProp]

I'm not that sure about last statement. In fact I think most of the time we, commercial operators, have no clue about these things unless it's in a NOTAM.

CP

[chuks]

It seems unlikely that a drone small enough not to leave noticeable wreckage would have been flown high enough to collide with an aircraft at FL330 (was it?).

Something such as a Global Hawk would leave a lot of wreckage, when that is the type of drone that would have been up that high.

[ATC Watcher]

Interesting discussion , regardless of the real cause of this accident ( and I also personally doubt the UAV theory ) :
Hotel Tango :If state or military operated, the operator would have full access to information on the traffic occupying that airspace.
definitively , however the vast majority of the UAvs accidents is when the operator contact is lost with the UAV a or if the UAV looses GPS contact and start doing things on its own , like descending for instance. And nobody likes to acknowledge they lost a UAV.

Chucks : It seems unlikely that a drone small enough not to leave noticeable wreckage would have been flown high enough to collide with an aircraft at FL330 (was it?).
Both the US and The Russians have small High Altitude UAVs weighting less that 100K Kgs with a ceiling of 50-60.000ft . I've seen photos but not sure if they were prototypes or operational crafts. So technically possible : yes ,likely in our case , I would say no.

Finally for the conspirationists, this occurred at an FIR boundary, always a nice place to run classified missions. especially a NATO border.:hmm:

[cappt]

Somebody claims to be leaking inside info over on the AvHerald comments.

[AAKEE]

http://theaviationist.com/2014/08/01...dish-airspace/ (http://theaviationist.com/2014/08/01...dish-airspace/)

There have been many cases of airspace violations in the region during the last few years. Pure speculation but if a state operated stealthy drone was transiting the area it's doubtful it would be talking to anyone other than the operator.
Lets hope this is not the case.


"That region" = over sea east of Sweden. But this was not "that region". It was border-close between Norway and Sweden. Good surveillance, both technical equipment and the will to keep control in the area.




Sweden only fly UAV in active restriction areas in Sweden. Highly regulated and taken very seriously by Swedish armed forces.


As for the radar picture linked in my last reply: In my eyes it sure looks like a raw/primary radar trace. I would guess on a military surveillance radar with both primary and secondary targets shown. For reference, the length of the trace is aprox. 1 minute of flight on the picture but it shows (guesstimated) about 100 radar position dots. The SSR-system, I think, don't produce close to that number of measurements in one minute.
But then, Im not in that bussiness, so I might be wrong about that.

[Sunamer]

Interesting discussion , regardless of the real cause of this accident ( and I also personally doubt the UAV theory ) :
Hotel Tango :
definitively , however the vast majority of the UAvs accidents is when the operator contact is lost with the UAV a or if the UAV looses GPS contact and start doing things on its own , like descending for instance. And nobody likes to acknowledge they lost a UAV.

Chucks :
Both the US and The Russians have small High Altitude UAVs weighting less that 100K Kgs with a ceiling of 50-60.000ft . I've seen photos but not sure if they were prototypes or operational crafts. So technically possible : yes ,likely in our case , I would say no.

Finally for the conspirationists, this occurred at an FIR boundary, always a nice place to run classified missions. especially a NATO border.:hmm:

There is no flying Russian UAV that can fly that high... usually service ceiling of known Russian UAVs is about 3000m-5000m / 10000-15000 ft (roughly). There is one that can presumably fly at 15000m (SKAT), but there is only one full scale version made out of wood for presentations and it was presented in 2007 . I am sure that when the time comes for actually flying it, the real service ceiling will be a lot more realistic.

[ATC Watcher]

Sunamer : There is no flying Russian UAV that can fly that high.
Good, then that narrows it down to one :E

AAKEE : the length of the trace is approx. 1 minute of flight
If you are correct then, if (and a big if) a collision occurred it would have almost certainly occur been well before that.
The SSR-system, I think, don't produce close to that number of measurements in one minute.
AAKEE what you see here in the photo you published is a synthetic radar picture , like a PC screen. You can put any update rate you want in the " settings " .
SSR returns depends on the number of actual radar heads fed into your system. If you use multi-radar tracking ( most if systems do today) you can have updates every second if you wish. but what you will see will be a calculated mean position, not the actual exact position at a given time . You can also make it a constant moving target , with the software filling the blanks in between returns .
The whole thing is pretty accurate, in the 0,1 NM range, and more than sufficient for ATC purposes .
You can also feed the primary radar returns in that system, but they will be digitized and shown separately from the SRR.

Now I have heard the investigation team has analysed both the CVR which gives a clue apparently,and the FDR, so we should know soon what happened.

[BluSdUp]

Hi All
It has been a bit to quiet on this one. Cargo no issue as Norwegian Post has received and destructed what mail the crash did not already take care of.

You Regional Drivers, has Bombardier come out with any teck advice or reminders of sop etc. Check wing nut etc.?

And i understand Xfiles are getting back! Drone ,, Please!
Anyway, no news from Bombardier and or MOT: No teck or structure problem.

I wonder what Murphy is up to this time!
Regards
Cpt B

[AAKEE]

SSR returns depends on the number of actual radar heads fed into your system. If you use multi-radar tracking ( most if systems do today) you can have updates every second if you wish.



@ATC Watcher:
Looks like a lot of hits per second. Most times a XPDR only shows returns about one/second ? This area actually is in the middle of nowhere and Swedish ATC only have coverage at high levels about FL100 and above.
I dont Think there is that many SSR-radars covering the area, counting Swedish and Norwegian together.


Now I have heard the investigation team has analysed both the CVR which gives a clue apparently,and the FDR, so we should know soon what happened.


Yes, they said about one week ago that they got clues from the CVR and was about to analyze the FDR. Preliminay report in a few weeks, i Think the statement was.


For all: I intruded a restricted area yesterday(only by 100 meters in a sharp corner), resulted in UAV couldnt take off due to the Swedish restrictions. Those regulations are kept strict and I think everyone can easy rule out the possibility of a Swedish UAV in that area( disregarding the fact that they cant even reach FL330). Together with what we know from other incidents in the area I think we also know that the primary radar systems in the area are quite good, making the UAV-rumor less probable.

[M609]

I dont Think there is that many SSR-radars covering the area, counting Swedish and Norwegian together.

Wrong

The NATO recognised air picture takes feeds from both civ and MIL radar sites. (The screenshot is from that system) I cannot comment on here about the MIL feeds, but I can comment that of the Avinor (Norwegian ANSP) radar sites, at least five SSR/MSSR sites would cover the area at cruise FL, and 3 would cover it down to FL100 or lower. Let´s just say that Norwegian controllers have had way better radar coverage in northern Sweden for the last 25 years than the civ controllers in Sweden.

On that you can add X number of AD radars.

[Teddy Robinson]

The amount of white noise and conspiracy type theories appearing on these forums is becoming not just annoying. One 'Perhaps ... Can anyone shed any light' comment generates yards of piffle. People who know the aircraft and the environment don't really get a word in edge ways.

Perhaps this is what the "new owners" want. Forums with a professional tag attached to feed tabloid hacks with their next headline ending in a question mark.

The credibility of prune is ... Frankly ... Going to the dogs.

[Tourist]

http://imgs.xkcd.com/comics/conspiracy_theories.png

[Nemrytter]

The credibility of prune is ... Frankly ... Going to the dogs.You're about 5 years too late, but in the last few months it really seems to have become a 'spotters' forum.
Then again, this thread is by far not the worst example of that - there do seemt o be some good posts in here.

[PrivtPilotRadarTech]

I agree Nemrytter, I particularly appreciate the comments from people with knowledge of the aircraft type and the locale. Without this thread I wouldn't know that the CVR and FDR were recovered and read. I greatly appreciate updates like that.

[Slow and curious]

the sun, the moon and the truth.

(Buddha)

[ATC Watcher]

Don't be so negative, some people are at least learning how a radar system works .:E

[Pilot DAR]

I have first hand experience (last summer) with the radar in that area operated by Norway, Sweden, and Finland. VFR below 10,000 feet, I was twice warned well in advance that my track could carry me into another nation's airspace, and this is unwelcomed. I did not violate any airspace, but admit that I was not taking it as seriously as the nations were, and I respect their right to assert their airspace.

For how "out in the middle of nowhere" that area appears, ATC sure know what's happening! We flew on a flight plan down the Russian/Finnish boarder, about a mile inside Finland at their extreme northern boarder, and Finnish ATC requested that I fly farther away from the boarder. I complied.

[Oakape]

Interesting Tourist. Your stick figure mocks 'young earth-creationists', yet a couple of frames later he is praying to GOD, who is the young-earth creationist.

[Tourist]

Yes, well done. You spotted that.:rolleyes:

[LN-MOW]

I'm a little puzzled by some of the postings in this thread. Commercial aircraft flying domestic flights in Norway routinely file flightplans that cross into Sweden or Finland en route to their destination. Look at the map how Norway is shaped. Choosing another route would burn a lot of extra fuel.

Sweden responded to the accident as per the agreement between Norway and Sweden, as they did when the Norwegian Air Force L-100 crashed a few years ago.

[TRF4EVR]

Any update here? There are an awful lot of 600s flying around out there...you figure if it were a problem with the aircraft systems, there would be a bulletin out. But it's hard to figure what else it could have been...

[jack11111]

I'm surprised nothing has been said about the contents of the flight recorders.

[cappt]

Maybe they are waiting for the snow to melt so they can verify what is on the recorder.

[cappt]

Don't be tool, it was posted earlier. What is your malfunction?

Postflystyrten i Sverige: ? Vi må vente til bakken tiner - NRK Nordland - Lokale nyheter, TV og radio (http://www.nrk.no/nordland/postflystyrten-i-sverige_-_-vi-ma-vente-til-bakken-tiner-1.12744225)

https://translate.google.com/translate?sl=no&tl=en&js=y&prev=_t&hl=no&ie=UTF-8&u=http%3A%2F%2Fwww.nrk.no%2Fnordland%2Fpostflystyrten-i-sverige_-_-vi-ma-vente-til-bakken-tiner-1.12744225&edit-text=&act=url

[Machinbird]

Maybe they are waiting for the snow to melt so they can verify what is on the recorder. They probably know fairly well what happened.
They probably have serious concerns in understanding why it happened.
So perhaps there may be some clues in parts of the wreckage that will help confirm what fault pathway occurred to cause loss of the aircraft.

Even with an aircraft as badly fragmented as this one is, you can find control system positional clues from 'witness marks' on adjacent wreckage.

And for HT's benefit, comments policing the English language are over the top on this web site.:=
We only need to understand the intent behind the post. In this case, cappt appears to be flying the CRJ, so he would really like to have answers to why this aircraft crashed.

[Herod]

I'm not going to scroll back, but wasn't it stated earlier in this thread that the FDR and CVR had been recovered, and a preliminary report would be out soon?

[Radix]

Yes I believe so. I'm not scrolling back either.

[Machinbird]

On Jan 26th 2016 the SHK reported that the investigation managed to read out both cockpit voice and flight data recorder, the CVR does contain the talks of the crew during the accident flight. The investigation is currently analysing and validating the recordings. A preliminary report is estimated to be released in a week or two.Quote from AvHerald, Crash: West Atlantic Sweden CRJ2 near Akkajaure on Jan 8th 2016, lost height after emergency call (http://avherald.com/h?article=4920a18a&opt=0)
So they have had the data for slightly over a month at this time.

[MrSnuggles]

This is the official investigation page for this event:

Investigations - Accident in the arctic north of Sweden to a Canadair CRJ 200 aircraft (SE-DUX) (http://www.havkom.se/en/investigations/civil-luftfart/olycka-i-lappland-med-flygplanet-se-dux-av-typen-canadair-crj-200)

Urgent news will be presented asap, otherwise we will have to wait until the official meeting to get an interim.

Then there are always journalists with connections.... I will update you when I find something!

[MrSnuggles]

Phoenix

Nose - not quite, too deep in the snow, need summer for 100% verification.
Tail - not to my knowledge.
Wingtips - not to my knowledge, but wings were def. located and parts of them can be seen on the pics.

[j71]

Onsdag presenteres tekniske funn fra Postflyulykken -itromso.no (http://www.itromso.no/nyheter/2016/03/07/Onsdag-presenteres-tekniske-funn-fra-Postflyulykken-12247572.ece)

Not too many details in the article, but there's a preliminary report coming in a couple of days. Might be worth keeping an eye open for that one.

[MrSnuggles]

In these times of outsourcing everything, it sometimes comes back to bite you. Related to this crash is the incompetence of some gouvernment agencies to get things right. Not only because they are incompetent but because the law demands of them to make the cheapest buy, unless you can motivate really REALLY well why you should not.

Räddningshelikoptern nådde inte fram ? fiasko vid haverilarm - Uppdrag Granskning | SVT.se (http://www.svt.se/ug/sjofartsverkets-nya-helikopter-kom-aldrig-fram-till-olycksplatsen)

Swedish Sjöfartsverket (agency for marine activities, especially in the Baltic Sea) bought a brand new all-fancy awesome bling helicopter from Augusta Westland (AW139) that was supposed to do awe-inspiring awesome things. Well, it didn't happen that way.

The night this crash happened, this fancy piece of kit couldn't take off until 1:20 after being called for. Then the fuel froze after refuelling. Then the crew refused to take off.

Head of Sjöfartsverket blames this on many things. Like, "this was not our task" or "you can't expect us to ferry people with our new awesome toy". The most interesting thing was "well, this is a difficult terrain so we have to prepare accordingly". I can get that. But, why didn't you prepare already?

This is the reason the SVT (Swedish national television) helicopter was the first on the crash site. This is also the reason the Norwegian F16 was tasked to find the wreckage.

Helicopters that actually got to the place when needed were Norwegian and Swedish ambulance helicopters. It seems health care personnel is more prepared than personnel whose actual task it is to actually get involved in events like this.

When Sweden bought these helicopters for an insane amount of money (some three years ago), it was just because they motivated it REALLY well by saying that they were excellently built for arctic environments and would be super prepared for anything the northern Swedish winter ever could throw at them.

Oh well. Seems like TV crews are better equipped, maybe Sjöfartsverket should talk to SVT about helicopter buys in the future?

[172_driver]

Snuggles,

Have you read Sjöfartsverkets response to media's 'investigation'? Watch the 8 minute video and time line of what happened that night. The FAQ section also answers lots of questions media never touched upon. SVT thought they could have a field day. State-owned media who could rather spend their energy on educating people than a tabloid look a like documentary.

Sjöfartsverket kommenterar Uppdrag gransknings uppgifter - Sjofartsverket (http://www.sjofartsverket.se/sv/Press/Sjofartsverket-kommenterar-Uppdrag-granskning-/)

[MrSnuggles]

172_driver yes, sure sure, all kinds of explanations.

Anyway, update from Statens Haverikommission (SHK) this morning! Brand new from the press, not published in any paper yet!

?Besättningen reagerade och kopplade ur autopiloten? - P4 Norrbotten | Sveriges Radio (http://sverigesradio.se/sida/artikel.aspx?programid=98&artikel=6386014)

Ett larm aktiveras och vinkeln på höjdrodret ändras så att nosen sänks. Motorerna får för lågt oljetryck. En varning hörs på att det är hög lutningsvinkeln. Ett nödanrop kvitteras av flygledningen.

My translation:

An alarm is activated and the angle of horizontal stabiliser is changed so the nose is lowered. The engines gets too low oil pressure. An aural warning sounds, alerting for too high slope angle*. A mayday is recognised by ATC.

Men besättningen regarade på att något inte var som det skulle och kopplade ut autopiloten. Förloppet ska ha varit under en och en halv minut. [..] Man pratar om fyra värden som inte överenstämmer med flygplanets läge. [..] Bland annat om den information som piloterna har på sina skärmar överensstämde med varandra.
My translation:

The crew reacted on something out of the ordinary and disconnected the autopilot. The whole event took place in less than 90 seconds. [..] SHK is commenting that four values (from the black boxes, my remark) does not agree with the information about the location of the plane** [..] Among those (values) it is unclear if the information on the pilots' screens were in sync.

Något tydligt svar på vad som orskade olyckan finns inte men något har hänt så att planet häftigt har vickat ner nosen och snabbt tappat höjd.

My translation:

There is no clear answer on what happened, but something took place so the plane made a rapid nose down movement and quickly lost altitude.

------------

* Here I am not sure what they really mean, someone may have a better explanation for this. "lutning" = slope, "vinkel" = angle, but it doesn't make sense even in Swedish.

** What position of the plane they refer to is not clear. No explanation if it is radar coordinates before or during the descent or GPS coordinates for the crash or whatever.

[AAKEE]

Hanging on to MrSnuggles:


*) = lutningsvinkel = bank angle. ( = Alarm for high bank angle in the text reffered to)


**) = Läge = should be read as "Attitude". The four values that was not correct came from IRU1. Pitch and bank angle, the also mentioned magnetic track or heading and grounds speed. They was not crystal clear on this, but from the fact that all these values was from the same source( IRU1).

[atakacs]

Well from that admittedly limited information it sounds like some dramatic structural failure... As for the why we don't seem much more informed at this stage.
Anything out of the CVR?

[MrSnuggles]

AAKEE

Thanks! Yes of course it should be "bank angle" now when you mention it! Attitude would also be the proper translation for what was mentioned as a "position". Thankyou!

atakacs

No interesting information regarding CVR, except for mentioning the warning sound about bank angle. Both black boxes were severely damaged in the crash but have been fully examined and all possible data has been retrieved. Now they need to make sense of it, try to sync it and see what data is missing during which time period etc.

A little snippet from a West Atlantic pilot:

Svarta lådan gav indikationer på att den information som visats på displayer i cockpit KAN HA varit felaktiga och inte stämt överens med verkligheten.

The FDR gave indications that the information displayed in the cockpit MAY have been inaccurate and not correlated to reality.

[Mad (Flt) Scientist]

SHK has shared some FDR and CVR data in this statement.... SHK webaite: http://www.havkom.se/en/

[Machinbird]

Well from that admittedly limited information it sounds like some dramatic structural failure..
I do not read the comments that way at all. Seems as if an IRU failed and started the nose pitching down and perhaps the zero g caused momentary loss of oil pressure. The real question seems to be what was the crew seeing on their PFDs. There was a comment mid way down the presentation that seems to indicate that the crew tried to re-engage the autopilot!!!??? (If true, then that was a big part of the problem.)
Total duration of the event was about 90 seconds.

Final report is due in December. Lets hope that a lot of the details get filled in before then.

[MrSnuggles]

Machinebird

I read both the Swedish and English statements and nowhere did I find any reference to autopilot being re-engaged unless there are some subtleties about Mach trim that is linked only to autopilot re-engagement.

[snowfalcon2]

I watched the webcast from the presentation of the report. HAVKOM pointed out that four FDR channels (pitch, roll, ground speed and mag heading) were incompatible with other data after the event started. All these channels are generated by the IRU.
So they made a graph showing both the FDR pitch data and their "best effort estimate" of the actual pitch.
The graph shows that the FDR pitch suddenly indicated up. After 2-3 secs the estimate indicates a pitch down which increases, with -1g negative pitch acceleration.

To me, this would fit a scenario where the PF sees a pitch up on the PFD and reacts by pushing down and trimming nose down (as also recorded on other FDR channels). Overspeeding occurs after approx 15 seconds.
Note that the investigators did not confirm such a scenario, but did not deny it either.

[Machinbird]

Extracted from the preliminary accident report:
http://www.havkom.se/assets/reports/SRL-2016_01e.pdf
After one hour and ten minutes of flight, during the pilots approach
briefing, the pilot in command, who was seated in the left seat,
exclaimed a strong expression. Immediately thereafter the aural
warning for autopilot disconnect (named Cavalry Charge) was
activated. The disconnection was also confirmed by FDR data. The
warning sounded continuously during the following 18 seconds.
After the autopilot disengagement FDR data indicates that both left
and right elevators moved towards aircraft nose down position. Left
and right side angle of attack went towards negative values. The
aircraft entered a descent with vertical acceleration values that reached
a negative load corresponding to -1G.
After a few seconds of negative G-load the aircraft's warning system
was activated by a so-called Triple Chime
10
followed by an aural
warning (synthetic voice) for low engine oil pressure on both engines.
FDR data shows that the trim to the movable horizontal stabilizer was
activated manually and the trim position went from -0.9 degrees nose
up to 1.7 degrees nose down. An aural signal of the stabilizer trim
movement (Stab trim clacker), signifying a manual input longer than
three seconds, was activated in connection with this. Immediately
thereafter a warning for high bank angle was activated.
After 17 seconds from the start of the event, the maximum speed
(VMO), 315 knots was exceeded. The over speed warning was
activated and the vertical acceleration turned to positive values.
Another 16 seconds later, the first officer transmitted a “MAYDAY”
message that was confirmed by the air traffic control. The indicated
airspeed then exceeded 400 knots and the stabilizer trim was
reactivated and dropped to 0.3 degrees nose down. The Pilot in
Command called "Mach trim"
11
after which engine power was
reduced to idle.
During the further event the last valid FDR value shows that the speed
continued to increase up to 508 knots while the vertical acceleration
values were positive, with maximum values of approximately +3G.
FDR data shows that the aircraft's ailerons and spoilerons mainly were
deflected to the left during the event.
Radar data and the accident site position indicate that the track was
changed about 75 degrees to the right during the event.
The crew was active during the entire event. The dialogue between the
pilots consisted mainly of different perceptions regarding turn
directions. They also expressed the need to climb. The aircraft
collided with the ground one minute and twenty seconds after the
initial height loss.
Mr. Snuggles,
The interview in Dubai had this comment in it: (please make allowance for google translate) I do not see any such reference in the preliminary report.
Eleonor Norgren: There are no ready answers. But the crew regarade that something was not as it should, and coupled the autopilot. The process must have been under a minute and a half.

[MrSnuggles]

Machinebird

It is to me very very clear that google translate was not correctly tuned for this translation.

Your quote:

Eleonor Norgren: There are no ready answers. But the crew regarade that something was not as it should, and coupled the autopilot. The process must have been under a minute and a half.

is actually already partially translated by me in an earlier post. The original Swedish writing is as follows:

Eleonor Norgren: Det finns inga färdiga svar. Men besättningen regarade på att något inte var som det skulle och kopplade ut autopiloten. Förloppet ska ha varit under en och en halv minut.13:21, 9 March 2016


?Besättningen reagerade och kopplade ur autopiloten? - P4 Norrbotten | Sveriges Radio (http://sverigesradio.se/sida/artikel.aspx?programid=98&artikel=6386014)


My translation would absolutely be



There are no ready answers. The crew reacted on something that was not as it should and disconnected the autopilot. The process (/event/incident) should have taken less than a minute and a half.



Clearly a mistake from automatic translation.

[Machinbird]

MrSnuggles,
Thank you for the clarification. That makes better sense.

Looks like the guy flying was trying too hard to chase an illogical PFD display.

If the plane has been flying in stable flight with the trim set, why would you be running in a bunch of trim manually once control has been dumped in your lap? Zero g in cruise? That can't be good !

Sit back and size up the situation before you set out on your course of action. At least that is what I was taught.:hmm:

[Machinbird]

Picked this comment out of the report:
FDR data shows that the aircraft's ailerons and spoilerons mainly were
deflected to the left during the event.Looks like aeroelasticity might have sabotaged their attempts to level the wings once the speed became excessive. Assuming aeroeleastic effects (wing twist) were in play, they might still have been able to level wings by neutralizing aileron and applying gentle rudder input.

[champair79]

Not trying to defend or praise the crew as the report is still quite sparse. However, as pilots it's drummed into us to always trust your instruments and not your senses.

Machinbird, as you say going from perfectly trimmed to an illogical scenario in a few seconds should have alerted them to the fact that maybe the instruments were giving dodgy readouts. Surely a quick glance at the standby instruments would've confirmed they were straight and level to start with?

If this had happened in the day or with visible references outside I suspect the outcome would've been far more positive. All the holes lined up on this occasion...


Champ

[atakacs]

The process must have been under a minute and a half.

Fairly dramatic in any case - my money is still on some sort of structural failure as the trigger event.

[AAKEE]

Actually the first deviation from normal on the FRD data released was the pitch showing constant nose up with a rate of about 30 degrees in 4 seconds, until almost 90 degree nose up after 22s.
Second sign, A/P disconnect about one second after pitch moving upwards.
Until AP disconnet all other values vas normal, 1G and no pitch or roll commands or movements.
Does not look like structural failure. There is a clear connection between elevator position, AoA and G all the way down.
And its quite clear that the pitch values(from IRSIRU) is corrupt.

[Wrist Watch]

Essential information (CVR & FDR) from the preliminary report (http://www.havkom.se/assets/reports/SRL-2016_01e.pdf) for everyone's convenience:

CVR

(Throughout the transcript, different alarms, chimes, and warnings are continuously heard)

23:19:22 (CPT): [expletive]
23:19:29 (FO): [expletive]
23:19:30 (CPT): [expletive]
23:19:33 (FO): Come on
23:19:35 (CPT): Come on, help me, help me, help me
23:19:35 (FO): Turn right
23:19:36 (FO): What
23:19:37 (CPT): Help me, help me
23:19:38 (FO): Yes, I'm trying
23:19:40 (FO): Turn left, turn left
23:19:43 (FO): Turn left
23:19:44 (FO): No
23:19:50 - 23:20:09: FO transmits the standard mayday call and repeats it several times
23:19:59 (CPT): Mach trim
23:20:01 (FO): Trim, trim a lot
23:20:06 (FO): Turn left, turn left
23:20:14 (CPT): We need to climb, we need to climb
23:20:15 (FO): Yeah, we need to climb
23:20:16 (FO): Turn left, turn left
23:20:17 (CPT): No, continue right, continue
23:20:19 (CPT): Continue right
23:20:20 (FO): Ok
23:20:22 (CPT): No, help me, help me please
23:20:23 (FO): I don't know, I don't see anything
23:20:24 (FO): I think you are the right to correct [sic]
23:20:25 (CPT): Ok
23:20:26 (CPT): Ok, ok, ya
23:20:28 (CPT): [expletive]
23:20:31 (FO): [expletive]

FDR

(Apparently the recorded pitch angle is not compatible with the aircraft's motion. Recalculation of pitch angle is shown beneath the FDR)

https://i.imgur.com/ScI7umC.png

Recalculated (more likely) pitch angle information from TAS, altitude, and AoA:

https://i.imgur.com/8WukfMI.png

[cappt]

Immediately thereafter the aural
warning for autopilot disconnect (named Cavalry Charge) was
activated. The disconnection was also confirmed by FDR data. The
warning sounded continuously during the following 18 seconds.


When either pilot disconnects the autopilot the calvary charge aural will only alert once for about 2-3 seconds.
When the autopilot disconnects automatically because of a failure it will continue to sound the calvary charge aural until a pilot manually selects the autopilot disconnect switch and that will silence the aural.

It sounds to me like the autopilot disconnected automatically.

[Viper 7]

Runaway trim or a hyd hardover in pitch leading to UA?

:ooh:

[Fair_Weather_Flyer]

From my reading of the report I'd still think that a major failure was the cause of the accident. Sure, the crew were trying to control the aicraft to the bitter end; but so were the Alaska Airlines guys when their stab broke loose. They had zero chance. With any element of control, I'd expect a couple of partial recoveries, yet they went straight down.

I think that the investigators have some idea of what they are looking for. When the weather improves, I think that they will return to the accident site to confirm what they suspect.

[NiclasB]

Wrist watch: Actually, three parameters were listed as not compatible (on p.23 of the report): färdhastighet (ground speed), tippvinkel (pitch angle), and rollvinkel (roll angle).

[daikilo]

if they suspect htp runway then it needs to come out a.s.a.p., but also, what could have caused it.

[AAKEE]

As we can see on the posted FDR-data, pitch information was leading(but most certain, not true).
Elevator pos, trim pos, AoA and G was not affected until after A/P disconnect.
Does'nt look like any other failure but IRU/IRS.

[NiclasB]

So...to elaborate on AAKEE:s earlier summary:

1) A/P disconnect (due to incorrect pitch indication from IRU?).
2) PF pushes nose down 1s later (due to incorrect pitch indication on PFD?).
3) g loading and AOA follows.
4) PF pushes nose down multiple times in coming seconds.
5) Stab trim increases towards nose down pitch.
6) Alt decreases, speed increases until overspeed.
7) At overspeed warning PF pulls nose up (realizes instrument error?) but does not recover (aeroelasticity?).
8) RIP.

[AFTA]

If you look at the blue line of indicatet pitch it seems like when captain is diving with an estimated 30 to 40 degrees down the iru in fact is telling him that this is working because its comming down. Then the estimated pitch is reduced. Then it is going way up again and he is diving again to repeat what he is thinking is the correct recovery. Scary!

[MrSnuggles]

What would make the IRU fail so suddenly the autopilot would automatically disconnect (as per cappt's experience)? What would cause pitch angle to be extremely misleading?

Bad sensors? Icing on sensors? Sensors falling off in flight? Broken gyros? Is this a maintenance issue?

Right now the aircraft is pretty much frozen solid into the ice and snow in northern Sweden. Any investigation regarding instruments left up there would have to wait until spring.. that would be May at the earliest that far up north.

[cappt]

There should have been an EICAS and PFD warning message, when the two units driving PFD1+2 disagree.

Correct, a single chime caution followed by EFIS COMP MON or AHRS 1/2 failure message. The AHRS failing will remove the FD and kick off the associated yaw damper, disabling the autopilot (calvary charge)
I am not suggesting AHRS/IRU failure here, just one thing of several that will disconnect the autopilot.

Will the FDR record info from both PFD's and the standby info or only the captains/flying pilot?

[Machinbird]

I would think that normal procedure would be for CPT to fly AHRS1 to his PFD and FO would fly AHRS2 to his PFD, however looking at the text of the discussion between the two crew members, the FO doesn't seem to be aware of the problem with the CPT display. Does anyone else get the feeling that they were both on the same (failed) AHRS? Other than a previous failure of one AHRS, why would both crewmembers be using the same AHRS? Switchology?


Will the FDR record info from both PFD's and the standby info or only the captains/flying pilot? As I recall from AF447, there was a problem with only the Cpt data being recorded, and they could only infer what the RH indications probably were. Likely the same on the CRJ.:confused:

[snowfalcon2]

Will the FDR record info from both PFD's and the standby info or only the captains/flying pilot?

During normal conditions the DFDR is provided with attitude information from IRU 1 via the DCU 1. (from the interim report). IRU 1 also feeds PFD 1.

I wonder which IRU feeds the standby attitude indicator? Or is it a separate gyro?

I also wonder about similar accidents where in spite of warning chimes and flags on the PFD, the pilot has just chased the invalid attitude indicator? Something for human factors people and instrument designers to rethink?

[AndiKunzi]

bank angle at event:
initially: left aileron, followed by left bank;
then: right aileron until bank 0;
followed by: continuous, hard left aileron and a complete roll over to the left

At a first, superficial view I can't see a discrepancy between the roll inputs and the roll rate. Seem to corelate.

I only know the PFDs in GA airplanes, but at very high or low pitch angles, there are mainly chevrons and air or ground to see, leading attention to pitch instead of bank and making it a bit more difficult to control bank.

The conversation makes me think that there is a good chance that both PFDs were on IRU1, as Machinbird supposed. No call from the FO for need to pitch up. Would normally be the main objective in that situation, approaching VMO.

The stand-by PFD or AI should have a separate IRU.

[Mad (Flt) Scientist]

If you assume that the pilot was reacting to the displayed bank, then his inputs will appear to correlate with the bank angle, naturally. That doesnt, in itself, validate the bank angle. Indeed, if you look at about 23:19:50, thee are 5 to 10 seconds of sustained left wing down aileron (more than 10 deg) at a VERY high airspeed. This should roll the aircraft rapidly left wing down. It doesnt, it stays right wing down, according to the bank angle. So while the aileron correlates witn a pilot trying to correct the bank, the bank doesnt respond to the aileron. Suggesting bank is, as stated by SHK, unreliable.

Oh and at these speeds, the aircraft WILL respond to roll inputs, quickly. The aircraft, at least at this point, is still inside the certified envelope and is not subject to aeroelastic loss of control, as some have suggested might be occurring. By regulation, you have a minimum 15% margin above VD/MD, which in turn has a good margin to VMO/MMO. You have to be going incredibly fast to see the aeroelastic effects become significant.

The elevator also correlates with the displayed pitch - pushing whe pitched up or pitching up, pulling whe pitching down or pitched down - and no one is suggesting that validates pitch.

The standby is indeed truly independent. There were, at least in theory, three independent attitude sources available.

[AndiKunzi]

@ Mad FS:

The provided diagrams are labeled:
pitch > 0 means climb, and elevator > 0 commands up
whereas
bank > 0 means RT and aileron > 0 commands LT;
reversed reading for the bank part in the graphs.

Thus, the pitch commands seems to be reaction in opposite direction of the indicated, after a couple of seconds of drifting upwards.

The roll commands are in the same direction of the deflection:
aileron left, with roll rate to the left; then right, with rate to the right, then left with rate to the left.

At 23:19:50 the aircraft is already in a 150 ° left turn. Until then, it seems corelating.

I don't know if bank information in reversed flight is reliable nor how a CRJ behaves at such an attitude.

[NiclasB]

Andi, as the SHK did state that bank angle is unreliable I wouldn't put too much interpretation into it.

What does strike me (again) is how important it is to have the CVR data as well as the FDR. Without the CVR we might spend hours (well, MORE hours... ;)) trying to decode what the pilots were trying to do. With the CVR at least we have a clue that - as QDM pointed out - their focus was initially on the bank, not the pitch.

/N

[chuks]

As pointed out, there are three sources of attitude information, the left and right displays, plus the standby, when two out of three should agree, with the standby often referred to as the "tie-breaker," since it's assumed that it should agree with the left or the right display, whichever one is correct.

From what we've been told, it reads as if the PF took the aircraft and tied it into a knot chasing an unreliable attitude display. From that point it was probably very difficult to figure out just what the airplane really was doing since it would have been at some extremes of pitch and bank, plus at negative G at times, and all on a dark night with little or no outside references available. Then to look at three displays and to pick the two that were correct would have been pretty difficult.

Is that 90 seconds from start to impact? That would imply a vertical speed of about 20 thousand feet per minute, or 300 knots.

[Machinbird]

Is that 90 seconds from start to impact? That would imply a vertical speed of about 20 thousand feet per minute, or 300 knots. Not at all unrealistic when you consider they impacted at over 500 kt.

I have only flown steam gauges, but it even there it can be an issue understanding the displays as you approach vertical flight. From what I've seen in mockups, modern PFDs are optimized for ~horizontal velocity vectors and may be completely inadequate for useful guidance in vertical flight.

Has anyone here ever done a loop in the CRJ simulator to see what the display does?

[cappt]

During extreme attitudes (-20/+30 or 65 deg bank) the PFD will de-clutter and red chevrons appear pointing to the direction of level flight.

I think this mostly industry standard now on EFIS equipped aircraft.

[Mad (Flt) Scientist]

@AK
@ Mad FS:

The provided diagrams are labeled:
pitch > 0 means climb, and elevator > 0 commands up
whereas
bank > 0 means RT and aileron > 0 commands LT;
reversed reading for the bank part in the graphs.

Thus, the pitch commands seems to be reaction in opposite direction of the indicated, after a couple of seconds of drifting upwards.

The roll commands are in the same direction of the deflection:
aileron left, with roll rate to the left; then right, with rate to the right, then left with rate to the left.

Sorry, the post quote function seems messed up so i can't do it "normally"

From 23:19:38 (approx) to 23:19:54, the ailerons are consistently positive. That means they are commanding left-wing-down roll (as noted on the plot and mentioned in your post). During that whole time the bank angle is positive - RIGHT wing down (again, as you note for the sign convention) - and INCREASES, which means rolling further to the right.

So the ailerons should be creating a left roll, but the bank trace rolls RIGHT. The roll commands are NOT in agreement with the bank response - they are in the sense to oppose the bank angle - suggesting crew action in response to the displayed bank, but that the crew action was not reflected in the bank angle recorded.

@Niclas - don't totally dismiss the bank. What SHK has said is that it doesn't seem to be compatible with the aircraft motion. they haven't said its "invalid" and it's probably a good assumption that the FDR was correctly recording the bank angle it was receiving, and that same bank angle (and pitch also) were being displayed to at least one set of cockpit displays. So it may be fundamental in determining why the accident happened. We just have to be careful in relating "indicated" attitudes to the likely "true" attitudes.

[F-16GUY]

Could it be that they encountered roll reversal due to being supersonic or transsonic? This will explain why the aircraft rolls opposite the command roll.

[AAKEE]

Could it be that they encountered roll reversal due to being supersonic or transsonic? This will explain why the aircraft rolls opposite the command roll.


A quick calc of IAS Vs altitude tells(wihout temperature corrections made) Mach topped about 0.95 around FL260. It was quite cold so I guess it came closer to transonic at lower alt, despite a FL-to-CAS-calc dont say so.

[F-16GUY]

7-cylinder man

At least I'm pro enough not to call others for amateurs. So now please enlighten all us amateurs. By the sound of it you got it all figured out.

My question referred to the timeframe between 23:19:38 and 23:19:54 where apparently the aircraft was rolling in the opposite direction of what was commanded. I do agree that loss of one PFD should not lead to the loss of the aircraft and its crew, but I wasn't there and I bet there is a lot of factors that the Swedish Board of Investigation will look into.

I would say that the only one jumping to conclusions right now is you...

[MrSnuggles]

7-cylinder man

Honestly, do you amateurs know nothing? Read and think why the FDR was recording what it was. It's all there.

An IRS/AHARS failure shouldn't lead to the loss of an aircraft - it's not even classes as an emergency procedure in any type I've flow; abnormal procedure yes.

From what has been published of the CVR recording the failure was never addressed or diagnosed by the crew. The PF seems to have jumped to a conclusion rather than diagnose the situation.

Put simple, the failure was not diagnosed by the crew and there was a rush to an incorrect conclusion.

I am intrigued. What is it in the FDR that is so simple we simpletons haven't figured it out? What was the actual failure according to you? What do you know about the FDR data that tells you about what actually went wrong?

I can agree that loss of one instrument or reading should not lead to loss of an aircraft. Still, that happens. Most of the times during night with no visual references. Just as in this case. That is sad.

On another note, I still wonder what might have broken with such short notice as hinted at on the CVR. The crew offers a few expletives and then the plane crashes within 90 seconds. Things went downhill even faster than any Airbus during malfunctioning FOs.

As Mr 7-cylinder man says, there are no clear indication on the CVR what went wrong. Some hints by the FO that they disagree on what direction to bank... maybe, depending on how you read it. Whatever happened it did so very sudden (as I read the CVR) and the crew was more occupied with trying to fly the plane than communicating with anyone. Is it possible that this lack of communication between the pilots indicates that they had the same (wrong) mental picture of the situation? May they both have been fed the wrong information somehow?

[Teddy Robinson]

I truly hope that there is a conclusion drawn from this accident when the final report is published. On first sight it looks very complex. It appears that we are into a what / who failed first endgame.

I have two cars, one is state of the .. and if something quits .. you pay BMW for a new box. The other is 1968 and of UK origin. If something quits you proabably knew about the possibility of failure, and the appropriate action anyway.

Times have changed.

[RatherBeFlying]

The nasty part about an attitude system failure is the crew can follow erroneous indications until it becomes apparent that the aircraft is in a very bad place.

By this point the other attitude sources will also be showing unusual attitudes and the crew will likely be in a situation they have never seen or trained before.

Lack of air data makes it difficult to demonstrate such a failure in a sim with good fidelity. Should we do certain upset training in military trainers?

Were there alerts for attitude systems disagree? If so, they seem not to have gotten the crew's attention in time:(

[cappt]

Were there alerts for attitude systems disagree? If so, they seem not to have gotten the crew's attention in time

Yes there are alerts. The alert would be a chime on the CVR.

[PersonFromPorlock]

How about equipping crews with night vision goggles, or pilots carrying their own? They aren't that expensive, and being able to see a visible horizon at night once the SHTF might be a life saver.

I don't mean they should be worn routinely at night, just available for quick donning.

[F-16GUY]

PersonFromPorlock,

Having flown more than 250 hours with NVG's in high performance military jets, I can assure you that NVG's are not part of the solution in this case. Below i will try to explain why:

NVG's are the single biggest killer in the fast jet business right now. This is due to two main reasons. Firstly, while wearing NVG's the pilot will lose all depth perception cues. This is not an issue for a civilian airliner on an IFR route, but for military aircraft flying all sort of tactical formations, it has led to many midairs and close calls. Secondly and more importantly, NVG's tend to lead to Spatial Disorientation among fast jet crews. Maneuvering violently on NVG's in a situation where the horizon is not constantly visible (steep dive) has led to many Spatial D attributed losses.

It takes me roughly 15 seconds to done my NVG's. But that is only possible because I am already wearing a helmet with a proper mount. Before each mission the NVG's are mounted on the helmet/head in the life support room and calibrated. This is necessary if one is to have the best possible result of wearing them.

The keys to succes in the use of NVG's are as follows. Always maintain the horizon in your crosscheck and always include a proper scan of your ADI. But the horizon is not always visible. For NVG's to work properly while used in aviation, the amount of light outside the cockpit has to be above 2,2 millilux. Or you could be in IMC conditions. Wearing NVG's in IMC conditions might also lead to Spatial D.

Then there is also the fact, that NVG's won't work properly if the cockpit lighting is NVG hostile. In military aircraft that use NVG's, there are normally to sets of cockpit lightings. One which is the normal white light, and one which is greenish and kan be selected on when flying on NVG's. The glow from non NVG compatible light will make the NVG's gain down on their own, thereby giving you a pure view outside the cockpit. The NVG hostile light also tends to be reflected in the canopy or windscreens which causes pure visibility.

Last but not least, the one thing that every military fast jet pilot learns when flying with NVG's, is to always be ready to focus on the ADI in case a Spatial D situation arises, since the NVG's will make the situation much worse.

Therefore as you can see, I find it hardly unlikely that a civilian pilot, with no training, in an aircraft with NVG hostile light, possibly in IMC conditions, and with only 90 seconds to live, will get any benefits from spending 15 seconds donning his NVG's, while he could have used the time better looking on his PFD's/ADI's (or what ever they are called) trying to determine which one is lying and which way is up.

[Machinbird]

F-16Guy,
A question if you please. Not having had the 'pleasure' of flying with NVG since they were just in their infancy when I was in a tactical role, what is this Special Disorientation? Is it due to latency (delay) in generating the view?

[Mad (Flt) Scientist]

I think he means SPATIAL disorientation. A quick google gave this hit near the top.
Rotor & Wing Magazine :: The Dangers of Spatial Disorientation??? (http://www.aviationtoday.com/rw/training/specialty/The-Dangers-of-Spatial-Disorientation&thinsp_72646.html#.VubZO_krLGg)
Recognizing spatial disorientation, especially when using night vision goggles (NVGs), is a key skillset that every pilot needs to learn.

[F-16GUY]

Sorry I meant Spatial Disorientation. English is not my native language.....

The link provided by Mad (Flt) Scientist explains it quite well.

There is no delay in the NVG's we use, and they are definitely not a "pleasure" to fly with in the long run since they are quite heavy. The entire CG of the helmet is moved forward when they are donned, and on long missions (3-4 hours), ones nose takes all the added weight.

[Machinbird]

Mad (Flt) Scientist and F16GUY:ok:
I've been spatially disoriented without using NVG.
We found out later that some anti-malarial drugs could cause it. No fun on a black a** night over the water.

[MOA]

Somatogravic illusion may have been at play here.

AP disconnects due to IRS failure; this failure generates ambiguous nose up display on P1 PFD. P1 pushes ND in response and aircraft accelerates. Both pilots now have sense of increasing pitch up. P1 pushes more as PFD is still showing pitch up. P2 'feels' pitch up but sees nose down on PFD but doesn't comment as they have the PFD miscompare - he may believe his in error. Only when they bring in the performance instruments do they realise something is wrong but as has been mentioned, the aircraft is now very poorly placed.

Pure conjecture, but dark nights with no visual references have caused aircraft to crash due to pilot disorientation even with perfectly serviceable instruments.

[cappt]

And the CVR did record a chime: it was there, right after the AP disconnect cavalry charge. And there were further chimes throughout the recording. None of the pilots mentioned any EICAS or PFD warnings though. They remained focused (mesmerized) trying to correct aircraft attitude.

NO, thats not the chime. The chime to look for would be right before the Captain said "what?"
The EFIS Comparator constantly monitors both sides and looks for disparities between the two. The chime would be the very first indication of an anomaly in the AHRS/IRU. The caution chime is followed by a flashing yellow push-to-cancel caution light on the glareshield and a red HDG/ATT flag on the primary flight display, with an associated EFIS COMP MON and possibly AHRS/IRU1 or 2 displayed on the EICAS.

So, maybe time to add a third system and use it as a tie-breaker when the two main systems disagree
It's already there, called the standby attitude indicator. The standby is a totally independent third system right in the middle of the cockpit. Some are a very nice digital ISI, others on the older A/C would be the steam gauge type.

[Machinbird]

The EFIS Comparator constantly monitors both sides and looks for disparities between the two.
Is this a comparison between the PFD displays or is it between the right and left attitude sources? Logically it should be the attitude sources, and if both PFDs are set to the same source for some reason, the warning chime may sound, but it might be lost in the confusion over what just happened.

Unless the accident investigation team finds an external source of data (such as radar glints on a primary radar) that gives them at least a few hard roll attitude data points, they will be just as lost as the accident aircrew was on what the actual roll attitude was.

Without discovering a valid source of attitude information, the probability of the crew recovering from their initial departure was nil. Is it really necessary to know the twists and turns of this aircraft on the way down to learn the necessary lessons from this accident?

[Volume]

Now, with three electronic devices, it should be easy to automatically compare all *three* signals - and provide a better hint as to which two are agreeing and which display is inconsistent with the rest.Read the Perpignan accident report to see, that exactly such automatic systems can make aircraft crash, if the only correct value is not displayed, because there are two wrong ones available...

[F-16GUY]

If, before a failure of an IRU, both pilots had been operating using the same source, they would have had clear indication(s) of that.

A basic skill for any pilot is to be able to identify discrepancies between displayed information and to interpret the cause. It really isn't that difficult, but it does often seem to me that it is becoming a lost skill.
7-cylinder man,

I agree that it really isn't difficult, but only if you get to practice it once in a while. And since it isn't practiced much today, along with basic manual flying skills, those skills are lost.

[Teddy Robinson]

Failure / degradation of the main attitude reference system naturally enough places higher emphasis on the standby instrument, normally an electrically driven gyro.
On all of the types I have encountered in commercial ops, this instrument rather small and positioned center left on the panel. Sure we have all practiced with it in the sim, normally as a stopgap to bring the main systems back online, but of course, when it is really needed on the proverbial dark and stormy night, it CAN get lost in all of the much brighter and noisier failure modes, and from the ones that I have used, once the aircraft is in a very bad place, it is not a great tool for recovery simply by virtue of its size.

Just thinking aloud, but perhaps something as simple as a ring of LED around this instrument that illuminates at a mis-compare signal (and training of course) might help in getting the attention to where it should be when things go pear.

[cappt]

If for some reason the FO had also selected the IRU1 source, then there was no chance of any warning being triggered when IRU1 started to go wild - displayed
The source select is a small rotary knob that take a firm grasp and rotation of 45 degrees from the normal position.
When using other than your primary source an amber ATT/HDG 1 or 2 is displayed across your PFD. It would have to be done intentionally and directed by the QRH handbook. That will have to be left to the investigators to determine.

[Mad (Flt) Scientist]

The normal mode of operation is independent attitude sources for each pilot. the only good reason to both be on the same source is if one is already identified as failed. in which case (1) it's made very clear that you are doing so (and cross-check with the standby would be even more important than normal) and (2) would you want the system nagging you the rest of the flight about a miscompare with an identified failed unit that you've already addressed.

There are good reasons to base the comparison monitoring on the displayed data.

[chuks]

It was sometime in the 1970s, around 1976 I think, that there was the crash of an HS-125 near Washington-Dulles Airport, Chantilly, Virginia, when the cause was determined to be the failure of one of the two attitude indicators. Then the pilot flying chose to follow the failed indicator, when I think that the aircraft came apart in flight.

That accident was followed by the requirement that a third attitude indicator be fitted, so that the crew can compare all three, to find that two agree. This is the reason that the standby attitude indicator is referred to as the "tie-breaker," when it is assumed that it shall indicate correctly to agree with the one of the two other systems that is also indicating correctly.

[Machinbird]

Would a failed IRU be something that might be dispatched under MEL guidelines? If so, there should be a record. If something happened inflight to fail one IRU significantly before the loss of control, there should be a record on the CVR. It would be highly improbable to have a second IRU failure in close time proximity, unless there was some sort of common failure mode and with the IRU units being located close to each other (eg. an electrical fire, an environmental control failure or ??)

I've had a few attitude gyro failures in my lifetime and it has been an easy matter to find the indicator that still follows the control motions, but that probably assumes you have not already grossly upset the applecart.

The Captain knew he had problems, but why oh why did he just cry "help me, help me?" He should have known where to find good information and latched onto it. I suspect a panic reaction shut down his reasoning processes, Panic generally results from inadequate training-not knowing instinctively what to do next.

If the Pilot Monitoring was doing his job and had good attitude information in front of him, he should have taken over control and stabilized the situation when the aircraft departed its assigned altitude and particularly when the PF began to ask for help. Either PM was just along for the ride and didn't believe or understand his instruments, had bad information in front of him, or was looking at other things trying to understand what core problem was.

Like AF447, the crew in this accident seemed to have very weak altitude awareness. I suspect that the design of many PFD displays hampers altitude awareness under distracting and dynamic conditions.

For you folks who are currently flying the line, I have a question. Wouldn't you as pilot monitoring know if the other guy/gal is 'losing the bubble' and beginning to lose control? Otherwise, what are you monitoring?

[Volume]

It would be interesting to learn whether this IRU had issues before, just like the RTLU for QZ8501...

[AtomKraft]

Looks like they got very odd pitch indication, and then tried to correct it by manoeuvring the aircraft.

Maybe the Captains PFD suddenly showed them they were climbing, so he pushed the nose over in an attempt to 'level' the aircraft?
Maybe they also were seeing an erroneous bank angle, which they also attempted to 'correct'?

It's so easy to chuck a comment in, but apart from asking why they didn't revert to the standbys, I think most folk would ask 'why do anything, straightaway?'.

If the aircraft was in straight and level flight, and some wonkiness appears on the flight instruments, I'd probably have held the controls where they were, and started looking around for the source of the trouble....bit like unreliable airspeed.

The other thing is, once things were clearly going pear shaped, does neither of them look at the altimeter?

Poor guys.:(

[F-16GUY]

Unfortunately when the poo hits the fan there will be no one other than the crew to resolve these sort of problems. Is that not what a professional pilot is required to do?

The failures would have been covered in the initial training. As well as the cycle of failures that will form the recurrent training by an ATO there is normally time to practice those little extra items if you ask the trainer.

These days we have the luxury of FCOMs in PFD format that can be read and studied on mobile devices. No excuse not to know the systems and procedures required in doing the job.

Not a dig at you 'F-16 guy'.
7-cylinder man,

In the perfect world that would be truth, but many resent events in the civilian aviation community have shown that training of basic ”pilot ****” is a thing of the past. Here I especially have incidents like Colgan Air 3407, Air France 447 and Air Asia 8501 in mind.

While I know that there are many professional and talented pilots in the civilian world, I also suspect that the ”Race to the Bottom”, created by the influence of low cost carriers world wide, have created room in the cockpits of commercial liners, for pilots that have less than 250 hours total time on machines that needs to be hand flown. And once those pilots get into the RH seat in a larger machine, the amount of ”stick time” that they will get is ridiculously small. They will never really learn to feel and fly their aircraft.

Now put a pilot like that in a Partial Panel situation where he has to hand fly his machine back to a safe landing, and best case it will be ugly but he will live, and worst case he will crash his aircraft within 60 seconds.

Many companies have been very reluctant to allow pilots to hone their skills in the air when conditions permits, because it affects passenger comfort and it costs a bit of extra fuel. Then they say that pilots can practice their hand flying skills once a year in the simulator. Get real!

I am so fortunate to work for a “company” that does not get affected by the publics demand for cheap tickets. Therefore we have the luxury of writing all our SOP’s and regulation with one thing as the main focus point. Safety!

Beside of the fact that most of the flying is "hands on", I get one ride in the simulator every 3 months where emergency procedures are practiced, as well as recovery from loss of control. Furthermore I get one instrument check ride in the simulator once a year, where Partial Panel and no giro emergencies have to be demonstrated. Why is that? Because when the **** hits the fan, the only thing that matters is proficiency. It does not matter if you get the most sophisticated presentation of your checklist on your screens or if you know all the systems by hart. If you are not able to fly the aircraft first with basic stick (yoke), rudder and throttle inputs, everything else does not matter.

In my “company” you are considered experienced when you have 1000 hours on type. Every time I read a safety report from the civilian world where it states that the both pilots where highly experienced and had several thousands hours on type, I cant help but thinking, I wonder how many hours of hand flying the type they got? Would they be able to hand fly their aircraft take-off to landing in IMC conditions even without some kind of failure? In my mind they should not be let loose in an aircraft if they 100% positively can.

Back to this incident in Sweden. We still miss a lot of information, but the SHK (Swedish Investigating Board) will in time tell us what went wrong and why the pilots where unable to correct the situation. One thing that I think is important to remember, is that if the accident was a result of poor pilot flying skills, the company and the regulators have a huge responsibility to make sure pilots get the necessary training.

[hoss183]

What worries me in this case was the lack of communication. There was no "wow my indicator is showing pitch down" - "Oh mine is showing pitch up"
Had the PF been following a duff indication, and the PM's display being good, that would have triggered further though and a glance at the standby indicator.
It seems to be the case in many accidents that the 2 pilots just aren't talking. (AF447 et al).

[Uplinker]

Good post F-16

On another note, I still wonder what might have broken with such short notice as hinted at on the CVR. The crew offers a few expletives and then the plane crashes within 90 seconds........


I am wondering if the Capt spilt his drink all over the centre console? This would account for the expletives from both - I can just imagine that happening. Then, the liquid started to cause short circuits and failures in the equipment as it dripped down. I don't know the physical avionics layout of the CRJ, but this is a possibility. The liquid could also have caused an IRU failure and/or the PFD source to switch so that both were on the same IRU. Faced with a rapid series of aircraft failures and cautions, and with hot coffee all over his trousers might explain why the Captain did not make a sensible reaction. (Although, the command 'you have control' might have helped).

Unfortunately when the poo hits the fan there will be no one other than the crew to resolve these sort of problems. Is that not what a professional pilot is required to do?

The failures would have been covered in the initial training. As well as the cycle of failures that will form the recurrent training by an ATO there is normally time to practice those little extra items if you ask the trainer.

These days we have the luxury of FCOMs in PFD format that can be read and studied on mobile devices. No excuse not to know the systems and procedures required in doing the job.

Yes, that is all well and good, but after average duty periods these days (i.e., long) and with today's average pilot rosters, folk are not going to be studying the FCOM on their phones in their precious time off.

In my experience, there is rarely spare time in the SIM, and even if there is, the other two want to bugger off so one feels one cannot ask for them to stay so you can practise something or look at a scenario.

Modern automatic aircraft are so complex that crews rarely get to experience all of the failure modes in the SIM. Even if they did experience all failures during initial training does not mean that they will have perfect recall of it and the appropriate actions on a dark and stormy night many years later.

In my opinion, not enough time is spent in recurrent SIMs practising unusual attitude recovery and instrument failures or unusual indications. Were this to be done, who knows, perhaps this crew and AF447's and many others would still be alive?

[_Phoenix]

Yet some people jump with findings and conclusions, as pilot error and poor CRM. We have no clue what happened and we are very far to know why.
Better try to figure out what possible happened. As example, I think they did a good job by keeping the wings at horizontal. The aircraft flight path wasn't a spiral (as per radar data). Moreover, the available FDR data after 23:20:10 shows that the roll indication was really wrong, they didn't inverted the aircraft. The two reliable data, as ground speed increase and positive gees, +1.5g to +2.5g are incompatible with roll data (aircraft inverted). For some reason they were unable to level up before hitting the ground.
By the way, the pilot is still more sharp than automation, the strong exclamation what(!) came couple of seconds earlier than AP disconnect.

[Machinbird]

positive gees, +1.5g to +2.5g are incompatible with roll data (aircraft inverted)._Phoenix
I can pull lots of g while inverted. To pull out of a dive requires that the g be applied in a consistent direction. If there is any significant roll rate, the time to pull out of a high speed dive ~ 20 seconds at modest g levels, will be much longer than the time to roll 180 degrees. SHK admits that they do not yet understand the roll data.

[_Phoenix]

Machinbird, I was pretty clear:
ground speed increase AND positive gees, +1.5g to +2.5g are incompatible with aircraft inverted.

[Tourist]

No, perfectly compatible.
Roll inverted any aircraft then pull.
You will accelerate and pull positive G

[despegue]

Syntax,

Sorry, but the crew WAS experienced. Why is it that people, even professionals still see hours as the ultimate?! It is irrelevant.
It are the amount of sectors flown which is important, and flying Night parcel cargo gives you plenty of sectors, at night, in all kinds of weather, often to smaller airports with less aids.



Your claim regarding the Nationalities of the crew not used to winter ops. Is again something I would expect from a wannabe who is completely wrong.
The crew was flying for the airline for several years,mand guess what, nearly all CRJ flights of West Atlantic are operated within Scandinavia.
Some of the worst Icing can be in Northern Spain by the way, and also France has its Icing issues.

[Machinbird]

ground speed increase AND positive gees, +1.5g to +2.5g are incompatible with aircraft inverted.
On appearances, you would be correct although an uncorrected roll rate (due to rolling PFD) could still foul up the recovery by turning the velocity vector.

However what is the source of the ground speed data? Is it the IRU or is it GPS? Once the IRU is corrupted, anything that it generates is suspect.

My personal opinion is that as long as the crew was operating from a corrupted attitude reference, the probability of recovery on a black night, possibly under instrument conditions, over sparsely inhabited terrain would be nil.

The altimeter would have told the story that they were being lied to and were out of control. They then needed to find a usable attitude reference such as the standby indicator and use that until level. Once stabilized they could go about selecting an operating IRU to display on the Captains PFD, or failing that, cover over the PFD with a piece of paper to prevent distraction. Any Instrument Rated pilot who cannot operate at a moments notice off the standby indicator is not ready to be flying instruments. You never know when the guy with the bony finger might administer a flight check of your competence.:uhoh:

[F-16GUY]

Machinbird,

Funny you said it, my personal technic is to use one of my flight gloves to cover the affected ADI if its to distracting. However this will only work under positive g's....

[Uplinker]

This has probably been mentioned, but I don't have the time to check the whole thread:

According to the FDR traces in #173, the right elevator appears to be acting strangely. There are five or six areas on the trace where it is deflecting when the left elevator isn't and vice versa.

I wonder if there was a flight control problem? I have never flown the CRJ and I don't know its technical arrangement - is each elevator controlled by a different computer? Or perhaps they had a hydraulic system failure which only affected one side?

[Mad (Flt) Scientist]

@uplinker

CRJ primary flight controls are mechanically signalled from cockpit to the PCUs - cables (mainly) and rods and levers - no computers involved. (There are electronics with pretty limited capabilities involved in the command of the Hstab and the spoilerons, bot not elevator, aileron or rudder). Also, both elevators are powered by dual hydraulics, so a single hydraulic would not prevent control on one side. (But see below)

Regarding the trace you comment on. Be very careful looking at left-right differences in FDR data. Often, as is the case here, left and right parameters are recorded asynchronously. The little dots show the actual data points - the lines are merely conjecture by 'joining the dots'. So in cases of rapid movement, the lines can appear to disagree because each is "cutting the corner" between mislaigned data 'dots'. As a result I would tend not to worry about any "spikes" where only one or two data points seem to disagree - you don't actually know what the position of the other elevator is AT THE SAME TIME. Both may be in step with each other for all you know.

There are two places where there seems to be a split between the traces - shortly after the point where the overspeed warning started according to the trace. It is possible that hinge moments on the elevator at high speeds and (relatively) high deflections at that speed slightly limited the elevator one side more than the other. There's no evidence of any hydraulic failure (we ought to have a warning I suspect, which no-one has yet pointed to, either on FDR or CVR) but IF such had occurred and affected a PCU on one side only, MAYBE that might explain HM limiting on one side only. But there can be other causes for that, including small amounts of sideslip, or roll, affecting the forces on each tail differently. Without some direct evidence of a hydraulic failure, I wouldn't conclude one from the elevator trace, personally.

[Uplinker]

OK, it seems weird - from the point of view of working out what happened - that the traces are not synchronised, but fair enough.

[Mad (Flt) Scientist]

The reason is more or less this: in 99% of cases the two asynchronous parameters are in sync anyway. So by recording them asynchronously I effectively get twice the sample rate for "elevator position". Only in the rare cases where they don't agree (disconnect pulled or mechanical failure, say) does that not apply. In the majority of THOSE cases, it's clear what is going on - for a jam, for example, you'd see one elevator stuck and one still moving. Add in CVR type evidence (which would confirm the disconnect had been pulled, for example) and you can pretty easily resolve any differences.

On older units, asynchronous recording was a way to capture both the required rates and record all the relevant items, since memory capacity was an issue. It's less so today, but old habits die hard.

[tdracer]

To elaborate slightly, DFDRs record in "frames" - the 'major' frame is typically 1 second, a major frame is made up of multiple 'minor' frames (the minor frame size depends on the recorder - older recorders were often 250 ms, newer are much faster). Even within a 'minor' frame, the recording is not synchronous - the recorder cycles through hundreds or even thousands of parameters during that minor frame so it's not a snapshot as such.


I've looked at lots of engine data from DFDRs with the parameters normally recorded at once per second (although sometimes slower). You quickly learn that rapidly changing parameters are basically +/- half a second relative to other parameters.

[TRF4EVR]

Still nothing on this? Doesn't this seem a bit weird with thousands of the things still flying around?

[TypeIV]

I think they're waiting for the snow to melt, if it was a failure of the display or instrumentation, how would they determine the cause from those bits and pieces?

[Machinbird]

...how would they determine the cause from those bits and pieces?Things like switch and knob positions may be available as well as non-volatile memory in some electronic devices. Witness marks will also validate the position of flight control surfaces and other movable components of interest.

[MrSnuggles]

TRF4EV3R

SHK has concluded there is something wrong with pitch, roll, heading data. FDR data shows values that would not correspond to the actual movement of the airplane. To further investigate this they need to recover instruments et al from the wreckage to study witness marks or other possible signs (knob positions) of what may have malfunctioned.

Right now the wreckage is frozen into what I would describe as a temporary glacier kind of environment. The snow on the impact point was very solid and melted temporarily when the aircraft struck. It then re-froze and to retrieve items from it would need special equipment. Problem is, this area is so remote there are no roads and the only way in during snow season is by snow mobile or helicopter. Obviously you can not transport heavy machinery on either of these transportation modes so we need to wait until spring when the snow melts. This would possibly mean May or even June, so until then there are few possibilities of recovery of important instruments.

Last thing I read about this was in Norwegian media (nrk.no) the 8th of March.

[atakacs]

Any news on this one ? I guess weather should be more amenable these days...

[pattern_is_full]

"More amenable" is a relative term.

We are talking about a site in the sub-arctic (Lat 68°N) at 1000m elevation on an inaccessible mountainside, and buried by impact in the snow pack.

Could be August before the snow melts enough to be handled with man/helo-portable equipment. Current Tromsø weather forecast indicates they are expecting rain and clouds most of this week, which may mean the mountain site is "socked in" and not accessible even to helos.

[RYFQB]

Sounds like work at the site is about to start up again - but not really for the sake of the investigation. Google translate (source (http://nsd.se/nyheter/stortade-postflyget-ska-bargas-10078710.aspx)): The Norwegian postal aircraft that crashed in northern Lapland mountains this winter will now be brought in and the crash area to be cleaned up, reports the P4 Norrbotten.

A third of the fuselage and the black boxes were recovered this past winter. Now it's about to collect the debris by hand in the fragile mountain environment.

- Mainly for the animals. You do not want a lot of scrap that can get caught in the claws or whatever may happen to it, said Johan Strandberg at the Swedish Environmental Research Institute is responsible for the clean-up.

While all the mail that was spread over the mountain during the crash will be taken care of.

[Mad (Flt) Scientist]

Kind of macabre, but is this not also possibly to recover the remains of the crew?

[MrSnuggles]

Sveriges Radio P4 Norrbotten is a radio channel that covers the area where the plane crashed. They are reporting that work with retrieving plane parts have started (as reported the 13th of June) and they are concerned about how the remaining fuel might affect wild life.

Nothing is mentioned about the crew, but having a little knowledge about the area, I would suspect there is very little to do. Polar foxes, wolves, lynx, bears and other predators might have already done their deeds. As I said before, this area is very remote and there are no roads. The ground has not been stable enough (or snow free enough) for retrieving crews to get there until now. Northern Sweden is very similar to, lets say, Alaska, for you who wonder about the environment in which the plane crashed.

I am hoping they find wreckage that might explain why the IRU stopped working! Nothing is mentioned about that in the broadcast.

For those who are interested in hearing Swedish: a link to the broadcast: Det norska postflyget ska nu bärgas - P4 Norrbotten | Sveriges Radio (http://sverigesradio.se/sida/artikel.aspx?programid=98&artikel=6451968)

Sorry I didn't update this immediately I found it. Been busy!

[cappt]

Just an interesting incident.
A recent CRJ lost all airspeed indications over Switzerland.

http://avherald.com/h?article=499b2f03&opt=0

[akaSylvia]

Hoping for an update on this!

[MrSnuggles]

Update on this:

Nothing.

Not a word. Zero. Not even local local radio has said anything to my knowledge. Granted, I doubt I know about all amateur radios with very short range capabilities, but the channels I can reach - zilch. Also granted, I am not privy to internal information within Svenska Haverikommissionen - simply because I do not work there... :-)

The official site from SHK - Statens haverikommission (http://www.havkom.se) is equally quiet. They are working with French, Norwegian, Spanish officials. No mention of an estimated month of completion of the report.

I get the feeling this IRU problem might be a hard one to crack. Still, some little tidbit of information would be nice.

[hoss183]

Final report seems to be out
Utredningar - Olycka vid Oajevágge i Jokkmokks kommun med flygplanet SE-DUX av typen Canadair CRJ 200 (http://www.havkom.se/utredningar/civil-luftfart/olycka-i-lappland-med-flygplanet-se-dux-av-typen-canadair-crj-200)
In Swedish, anyone feel like translating it?

[FlyingStone]

http://www.havkom.se/assets/reports/RL-2016_11e.pdf

[ATC Watcher]

quote 1 : the aeroplane was level flight at FL330 when the incident occurred .
quote 2 : The aeroplane collided with the ground in an inverted position at t80,
one minute and twenty seconds after the start of the event.
quote 3 : The erroneous attitude indication on PFD 1 was caused by a malfunction of the Inertial Reference Unit (IRU 1).
quote 4 :The accident was caused by insufficient operational prerequisites for the management of a failure in a redundant system.

Frightening to read the sequence of events . if you think it could have been be you.

[semmern]

So, once again, instrument failure leading to a crash. The holes in the Swiss cheese line up yet again.. A chilling read!

[Latchman]

http://www.havkom.se/assets/reports/RL-2016_11e.pdfh)

[MrSnuggles]

According to my understanding of the report, this would be a probable sequence of events:

Pilots briefing maps, using lights and reducing night vision.
IRU malfunctioning.
Pilots startled by strange PFD displays.
Pilots taking action.

No communication who is in control and no double checking of instruments can be heard on the CVR.

This was one malfunctioning instrument that would have been easy to spot if a comparison had been made between LHS and RHS. Noone did, noone thought "pitch, power" and landed safely.

How many AF447 will there continue to be?