Helicopter crash in Norway today

[TowerDog]

Looks like this company lost a chopper just now.
https://helitrans.no/
Reports says 6 souls on board, no details yet.

[TowerDog]

4 people confirmed killed.
The accident happened near the Arctic town of Alta.
Still no further details, but the weather seemed clear (from news clips in Norwegian media)

[TowerDog]

Airbus 360 Helicopter according to this paper: https://www.altaposten.no/nyheter/2019/08/31/Helikopter-med-seks-ombord-styrtet-i-Alta-19826759.ece

Article in Norwegian with a few pictures from the scene.

[jymil]

AS350 LN-OFU. Just speculating: jack stall / servo transparency ?

[TowerDog]

AS350 LN-OFU. Just speculating: jack stall / servo transparency ?

Eye witness saw it flying very low, then into the hill, but of course it could have been higher with a mechanical forcing it down rather than a CFIT. Good VFR, several witnesses and 2 survivors.
Sad.

[SASless]

There you go....case solved.....Jack Stall caused it!

That was a new PPRuNe Record time for the cause of an accident being determined.:ugh:

[TowerDog]

There you go....case solved.....Jack Stall caused it!

That was a new PPRuNe Record time for the cause of an accident being determined.:ugh:

Well, he was speculating, perhaps hasty, but not concluding a cause.

[SASless]

TD.....you better pull. out your Webster's and read up on the definition of "speculation".

[TowerDog]

TD.....you better pull. out your Webster's and read up on the definition of "speculation".

Oops.
Sorry about that: I did pull out the online dictionary, and you are correct Sir.
(Speaking too many languages and you get mixed up, especially as you get older.)
Mea Culpa, Mea Maxima Culpa.

[jymil]

There you go....case solved.....Jack Stall caused it!

That was a new PPRuNe Record time for the cause of an accident being determined.:ugh:
Not sure how you jump from "just speculating" to "case solved". CFIT is a plausible cause here. A mechanical problem not induced by the pilot is pretty unlikely for a 2 month old helicopter.

[DonQuixote23]

Could we perhaps be a little more respectful, hours after the accident?

[Mutley1013]

Not sure how you jump from "just speculating" to "case solved". CFIT is a plausible cause here. A mechanical problem not induced by the pilot is pretty unlikely for a 2 month old helicopter.

Why would that be unlikely? How many times have machines gone down just after a service or overhaul due to an engineering mistake or component manufacturing issue? Not saying it is mechanical, just saying the age of helicopter surely no cast iron guarantee.

[helicrazi]

Not sure how you jump from "just speculating" to "case solved". CFIT is a plausible cause here. A mechanical problem not induced by the pilot is pretty unlikely for a 2 month old helicopter.

in my experience, it's the new ones that have the teething problems...

Godspeed to them all

[Nubian]

in my experience, it's the new ones that have the teething problems...

Godspeed to them all

For a new model perhaps.... this was not.

[Ancient Mariner]

Six now confirmed dead, Swedish pilot and five locals in their early twenties. Helicopter was performing sightseeing trips for festival participants.
Per

[Kulwin Park]

Can someone describe Jack Stall / Servo Transperancy as mentioned above. What exactly is it?
I'm guessing the servos lock up, and it can't be overridden.
Do the accumulators help on the AS350?

[SASless]

This topic has been discussed in detail a couple of times here at Rotorheads.


https://www.pprune.org/rotorheads/print-233275-jack-stall.html

https://www.pprune.org/rotorheads/254165-jackstall-what-any-experiences-2.html

[Bell_ringer]

The Norwegians must offer quite the scenic tour experience if they are able to end up in jackstall.

[GrayHorizonsHeli]

Happens more than you think.
I had a pilot at the end of tree-planting season, giving all the tree-planters a ride of their life, high G turns, negative G pushovers, steep banks, nap of the earth stuff....funny thing when he was in view of camp, he flew like a fricken angel. Cant let the wrench see what he was doing you know.
guess he didn't realize sound travels and i could hear every twist, turn and bank from miles away.

bottom line, many pilots fall prey to giving the passengers a ride to remember...if they survive.

[SASless]

Mechanics (Engineers for those who prefer that title) have done in many a Pilot and Passengers too....so what is your point re this particular tragedy?

[Nubian]

No, I'm talking new s92s, still with problems, they aren't new models

Problems that can cause a crash? I think not.

The 350 however, is infamously known for what jymil suggest regardless of what you and others might say and have caused several accidents with multiple deaths. One of the more profiled accidents happened in the Grand Canyon in 2003 and the pictures/video collected from the pax's cameras is the reason the Appareo Vision 1000 comes standard in these helicopters today.

Bell_ringer,
Not at all if you know what you're talking about.
The American pilots are also able to provide quite a ride, and there are examples from the rest of the world too.
https://www.pprune.org/rotorheads/103113-grand-canyon-not-forgiving-place.html?highlight=sundance+helicopters (link to the above accident)

Here's a link to another accident with same outcome from Norway being discussed here.
https://www.pprune.org/rotorheads/625118-helicopter-crash-norway-today-2.html

For the ones that have got the proper training in the 350, this is old news and is easily avoided.

Kulwin Park,
The short explanation is: when you load the disk beyond the capability of the Hydraulic system, the controls lock up. It disappears as quickly as it comes when the severity of the manoeuvre is reduced. A 350 doing high G manoeuvres at high speed and close to AUW it is really easy to get it in, and one must have sufficient clearance to obstacles in order to recover.

Now, of course it can be a lot of other reasons for this crash.

It's a sad loss regardless the cause of it!

[helicrazi]

Cause a crash? Google west Franklin s92

[Nubian]

Cause a crash? Google west Franklin s92

Bad example I’d say.

[SASless]

Nubian,

Question.....if the 350 is known to have a hydraulic system that can be overcome by feedback forces and thus allow a loss of Pilot control of the aircraft.....why has that not been addressed and modifications made so that the flight control system can function under all flight conditions the aircraft can be expected to encounter?

From past discussions here at Rotorheads, it was noted one particular manufacturer seemed to design aircraft that had that flaw.

From discussions about LTE....again we see one maker that seemed to overlook that problem in their aircraft until it became a PR problem that affected marketing.

What role should the certification authorities play in this?

I guess that is really two questions...one re the manufacturer and the second being the certification authorities.

[TIMTS]

All onboard now confirmed dead. One died in hospital, and one was missing for a while. I guess that's where the "2 survivors" came from.

[[email protected]]

But you have to be properly ham-fisted even at High AUM to generate the sort of feedback forces that will stall the jacks - and you have to hold it in the stalled condition since it is almost self correcting if you ease off the load.

[GrayHorizonsHeli]

Mechanics (Engineers for those who prefer that title) have done in many a Pilot and Passengers too....so what is your point re this particular tragedy?


the stats dont back this up at all, at least comparatively from one profession to the other.
you're a smart man, you figure it out without speculating.

[GrayHorizonsHeli]

This is the last aircraft I dealt with that involved servo transparency, he ran out of time and space, like most of these scenarios as they repeat themselves.
The TSB report details some good info that answers some questions or accusations here.

http://www.bst-tsb.gc.ca/eng/rapports-reports/aviation/2016/a16p0045/A16P0045.pdf


"According to Airbus Helicopters, the phenomenon of servo transparency can occur “during excessive maneuvering of any single hydraulic system equipped helicopter, if operated beyond its approved flight envelope.” The manufacturer does not consider servo transparency a failure of the system, but a limitation of all single hydraulic systems. Unlike in the case of a hydraulic system failure, there is no visual or aural indication to alert the pilot that the hydraulic system is approaching servo transparency...."

[Nubian]

Nubian,

Question.....if the 350 is known to have a hydraulic system that can be overcome by feedback forces and thus allow a loss of Pilot control of the aircraft.....why has that not been addressed and modifications made so that the flight control system can function under all flight conditions the aircraft can be expected to encounter?

From past discussions here at Rotorheads, it was noted one particular manufacturer seemed to design aircraft that had that flaw.

From discussions about LTE....again we see one maker that seemed to overlook that problem in their aircraft until it became a PR problem that affected marketing.

What role should the certification authorities play in this?

I guess that is really two questions...one re the manufacturer and the second being the certification authorities.

SAS,

Well, although the type has a reputation, it is worth to mention that it does not happen without exceeding limitations in order to experience it, but to do so is fairly easy.
To answer your first question: The manufacturer has addressed the problem with information on the subject. Airbus (back then Europcopter) published this: https://www.airbushelicopters.com/website/docs_wsw/pdf/LS1648-29-03-REV0-A.pdf
In order to give proper training required to recover from servo-transperancy you need to exceed the limitations in some way, so it is a bit of a Catch 22.
Now, what do you do when pilots exceeding the limitations and get into trouble? Redesigning the helicopter?

As to your second question, I don't agree that the manufacturers necessarily is overlooking the problems as what I already has said about exceeding limits. As for the certifying authority could look at it in a way that the limit for getting into this phenomenon is too low and come up with some type of sanction, if they deem it to be a significant problem. It has certainly caused a few deaths, but if that is due to lack of training is the question I guess.

[Jack Carson]

With all of the discussions concerning hydraulic flight control transparency why hasn’t the discussion addressed the possibility of a failure hydraulic pump belt drive. This could also result in the loss of control should the failure occurs at an inopportune time. Just Sayin!

[Same again]

It was very obviously caused by deep vein thrombosis (DVT).

[GrayHorizonsHeli]

Jack,

The new belt is alot more reliable than the old belt thats for sure
the pump/pulley assembly is vastly improved, although the bearings had some growing pains.
it is rare to suffer hydraulic failures now compared to years ago, but isn't impossible.

I also see, if the identification of the aircraft is correct, its a B3e, so it has dual hydraulics and dual pumps, one being direct drive off the MGB.
While the dual hydraulics have an overload sensor to warn you of impending servo transparency, it can be missed or ignored, it doesn't stop you from flying into the servo transparency
the final outcome of this accident will be an interesting read, but I fear it's just history repeating itself.

[jymil]

Is the dual hydraulics now standard on H125/AS350B3e ? I thought it was an optional item for the single engine squirrels.

[Nubian]

Jack,

The new belt is alot more reliable than the old belt thats for sure
the pump/pulley assembly is vastly improved, although the bearings had some growing pains.
it is rare to suffer hydraulic failures now compared to years ago, but isn't impossible.

I also see, if the identification of the aircraft is correct, its a B3e, so it has dual hydraulics and dual pumps, one being direct drive off the MGB.
While the dual hydraulics have an overload sensor to warn you of impending servo transparency, it can be missed or ignored, it doesn't stop you from flying into the servo transparency
the final outcome of this accident will be an interesting read, but I fear it's just history repeating itself.

The dual HYD is still an option and not a standard as some think.

[Jack Carson]

I flew both the B2 and theB3 in Phoenix, AZ more then 10 years ago. At that time there were issues with the belt drive system. Neither bird was equipped with the dual hyd system.

[GrayHorizonsHeli]

The dual HYD is still an option and not a standard as some think.

this is true, dont they call it the gross weight increase kit or something??
Either way, Ive only ever seen b3e's with dual hydraulics. I thought wrongly that everyone wanted dual hydraulics for the safety aspect.
the picture i found of this aircraft showed otherwise (swashplate boot visible). So unless someone can confirm otherwise, the belief is this a/c had single hydraulics.

[Winnie]

The 355 with Dual Hydraulics could STILL see "Transparancy," The machine even has a "LIMIT" light that triggers when near, ufortunately I don't have enough time in single engine 350's to verify if they all do too, I know the B3e does...

[Nubian]

this is true, dont they call it the gross weight increase kit or something??
Either way, Ive only ever seen b3e's with dual hydraulics. I thought wrongly that everyone wanted dual hydraulics for the safety aspect.
the picture i found of this aircraft showed otherwise (swashplate boot visible). So unless someone can confirm otherwise, the belief is this a/c had single hydraulics.

It will give you an increase in internal GW, but not for external loads so for a utility operator it does not make sense to pay lots for the extra weight of the kit, reduced payload and increased cost of operation (TBO of the MGB is reduced with this kit due to the extra mechanical drive from the MGB.)

Jack,

The machine was just a few months old.

https://aviation-safety.net/wikibase/228643

[staticsource]

The dual hydraulic 350s will have the limit light too, not the single hyd systems though. Not a very common upgrade in Europe but seems more popular across the pond?

[pettinger93]

if you read the report in the link given above, it does say that the dual hydraulic system in the B3 cannot easily be retro fitted to the B2 helicopter built with the single system, and that the single system has NO warning light, whereas the dual system does.

[BluSdUp]

The names of the PAX with pictures was just released on NRK.no.
5 great kids at the age of 19 to 22. Going for a joy ride at a festival.
Gone......

The State Attorney is getting all emotional and is loosing his cool and want the company, Heli Trans investigated ASAP.
The pilot is not named but described as a 27 man fairly new to the company.
Sad!

Cpt B

[JohnDixson]

Gray posted in part: “The manufacturer does not consider servo transparency a failure of the system, but a limitation of all single hydraulic systems”
Thanks for the AH statement, but I’m missing something. If the single servo system was designed to provide a control force which exceeds the maximum forces that can be generated by the rotor, this discussion, and the similar one for the Gazelle, would be moot, n’est-ce pas?

[AAKEE]

Gray posted in part: “The manufacturer does not consider servo transparency a failure of the system, but a limitation of all single hydraulic systems”
Thanks for the AH statement, but I’m missing something. If the single servo system was designed to provide a control force which exceeds the maximum forces that can be generated by the rotor, this discussion, and the similar one for the Gazelle, would be moot, n’est-ce pas?


They say it is the other way around. The limits of the hydraulic system is set to not overload the strenght of the rotor system to protect it from damage if the helo is operated outside the envelope.
Servo transparency (https://www.airbushelicopters.com/website/docs_wsw/pdf/LS1648-29-03-REV0-A.pdf)

Not saying that this is the safest way, only that is why the hyd-syst is limited in power.
I’d rather see it constructed as You say, but then the rotor system might need to be redesigned to cope with the forces.

[nomorehelosforme]

The names of the PAX with pictures was just released on NRK.no.
5 great kids at the age of 19 to 22. Going for a joy ride at a festival.
Gone......

The State Attorney is getting all emotional and is loosing his cool and want the company, Heli Trans investigated ASAP.
The pilot is not named but described as a 27 man fairly new to the company.
Sad!

Cpt B

This is an awful lot of young people with their lives ahead of them lost this summer in 2 accidents my sympathies to all involved in both accidents.

[SASless]

The limits of the hydraulic system is set to not overload the strenght of the rotor system to protect it from damage if the helo is operated outside the envelope.
Servo transparency (https://www.airbushelicopters.com/website/docs_wsw/pdf/LS1648-29-03-REV0-A.pdf)

After their hydraulic flight control system killed numerous people due to this occurrence they would say that wouldn't they!

Perish the thought we under designed our flight control system and and then cause the aircraft to crash killing the occupants because we did not wish to over stress a rotor blade or some sheet metal and rivets.

Why is it all the other helicopter designers seem to see the exact opposite way?

[JohnDixson]

Thanks AAKEE and as I think you would concur with SAS’ comments, allow a follow up to his observation: If one designs as I suggested ( BTW-this is the approach at SA just a disclaimer, so to speak ), then, when the pilot operates the controls such that the control loads become excessive ( the aggravating factor being stall or stall flutter ) the pilot is faced with very much higher vibration levels, and if for instance performed in turning flight, what was intended as a level turn maneuver may involve some rate of descent as the rotor lift I’d decreased by the stall, but those excessive control loads are within the design fatigue and static strength design parameters, and the controls don’t break-the pilot remains in control. As I wrote previously, I’m still a bit mystified as to the AH design philosophy. They are most certainly not amateurs and that is the reason for my curiosity.

[GrayHorizonsHeli]

Gray posted in part: “The manufacturer does not consider servo transparency a failure of the system, but a limitation of all single hydraulic systems”
Thanks for the AH statement, but I’m missing something. If the single servo system was designed to provide a control force which exceeds the maximum forces that can be generated by the rotor, this discussion, and the similar one for the Gazelle, would be moot, n’est-ce pas?


talk to airbus, not me. it's their quote

[ApolloHeli]

Some extra information in this article that hasn't been posted in this thread, and it's in english.

https://www.thelocal.se/20190901/swedish-pilot-and-five-others-die-in-norway-helicopter-crash

[SASless]

As usual in crashes of this type of helicopter....AS 350....we see immediate discussion of hydraulics issues...belts, pulleys, jack stall and fire post crash that evokes questions about crashworthiness of the fuel system.

We also hear talk of the. weakness of the airframe during high impact with the ground.

The aircraft is popular....and has good performance numbers.

Does the good really outweigh the bad in this machine or is its success profit driven?

Did the certifying authorities allow a problem machine to fly when perhaps they should not. have?

It is not like EC/AB helicopters have not made some engineering mistakes in their past.

Will we see the accident investigation of this tragedy record some similar finding from previous crashes that point to design issues?

[AAKEE]

Thanks AAKEE and as I think you would concur with SAS’ comments,

Yep, I guess we are on speaking terms.

I’m not qualified on the type. I think the jack stall problem is quite easy to avoid, theoretically.
If you have respect for it and fly it like AS/EC/AH built it, i think its safe in that perspective.
But I also think that the reason people get in this kind of trouble will continue to happen making it dangerous to those that dont stay inside the box(envelope).
AH can tell us it is safe inside the approved envelope but there will always be people that fly outside it.
(Not saying this accident was due to this).

[[email protected]]

The British military used the AS 350BB with a single hydraulic system as a basic trainer for 20 years flying tactical and low level profiles at high speed and managed not to experience jackstall/servo transparency in thousands of flying hours.

As I said before you have to be ham-fisted to get it to do that - stunting and bunting at high AUM with limited experience is a pretty good recipe though.

[BluSdUp]

NRK.no reports that some sort of data recorder has been recovered , but in bad shape.
This is not a proper FDR , so what is it exactly.
Anyone care to enlighten me?

Regards
Cpt B

[finalchecksplease]

NRK.no reports that some sort of data recorder has been recovered , but in bad shape.
This is not a proper FDR , so what is it exactly.
Anyone care to enlighten me?

Regards
Cpt B

Google "Appareo Vision 1000 Airbus Helicopters" and you will see what was fitted in the accident helicopter.

[BluSdUp]

Thanks
Handy little thing.
And its Black, ie a black Box. In this case I fear it is burnt to a crisp, but time will show.
According to the Investigation Team they have little to go by as most of the main body was consumed by the fire.

At NRK.no there is some emotional RT , as a Heli Team 212(?) happens to pass by makes a Mayday call which is relayed by WF Dash 8.
He eventually manage to set down to rescue a person outside the wreak , unfortunately this person later passed away.
The SAR Seaking was there quickly as well.
Some quick response by fellow RotorHeads, but to no avail.
So.
If this was a Technical problem: Fix it!
If this was a Operational problem : Fix it!
We owe those dead Kids.
Eh!?

Respectfully
Cpt B

[finalchecksplease]

BluSdUp

Have a look at this accident report, not much left over of aircraft after a post crash fire but they still got a lot of good data from the Vision 1000 unit: https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR1403.pdf
Not saying the accident investigators will this time but they might, of course FDR / CVR like in the bigger aircraft would be ideal but cost prohibitive, this a a great solution for the smaller helicopters.

[BluSdUp]

FinalChecks
Indeed not much left of that frame either, but the unit looks to have avoided the fire.
Lets hope it can be recovered in this case as well.
A small " Crash " box and it would stand a better chance.
Anyway
Thanks

[EMS R22]

Could we perhaps be a little more respectful, hours after the accident?

I agree. Thoughts are with the deceased family.
Horrible. RIP

[M609]

Norwegian media are reporting that Airbus Helicopters are mandating inspections of the connection between the engine and gearbox of certain new AS350, AS550 and EC130 models.

[Training Risky]

The British military used the AS 350BB with a single hydraulic system as a basic trainer for 20 years flying tactical and low level profiles at high speed and managed not to experience jackstall/servo transparency in thousands of flying hours.

As I said before you have to be ham-fisted to get it to do that - stunting and bunting at high AUM with limited experience is a pretty good recipe though.
Agreed. I did about 90 hrs on the Squirrel AS350 and it was very reliable. Quickstops and confined areas were comfortably handled by thousands of hamfisted students like me. Loss of hyds in the sim was recoverable and not too uncomfortable either. Glad I never saw it for real. RIP.

[GrayHorizonsHeli]

its ASB 63.00.32

its pertaining to the driveshaft flange bolts, both engine side and MGB side for proper installation.
Its not specific if its this B3e incident, other than it says a recent accident with an ongoing investigation.

[John R81]

Link to the EAD I just posted

http://publicapps.caa.co.uk/docs/33/EASAAD20190225E.pdf

[Jon Martinsen]

This is a ørintscreen of a video tanken 1.30 mins before the actual crash. Are there any errors showing up in the panel? Ibb.co/hLcnJqJ

[Nubian]

This is a ørintscreen of a video tanken 1.30 mins before the actual crash. Are there any errors showing up in the panel? Ibb.co/hLcnJqJ

No, (you can't see the whole warning panel in this picture). All parameters visible looks to be normal for controlled flight. Lots of fuel.

[ApolloHeli]

Can't see the VSI but doesn't 8FLI for 80kts/10° AOB seem like more power than necessary? Nose down attitude suggests the power isn't for a climb (that's how I interpret it).
(I'm alluding to potentially high disc loading and servo transparency with this question)

[M609]

5 of 6 bolts missing (https://translate.google.com/translate?sl=no&tl=en&u=https%3A%2F%2Fwww.nrk.no%2Ffinnmark%2Fhelikopterulykken_-her-mangler-fem-av-seks-bolter-1.14701672)

Google translate, but you get the major points.

[ApolloHeli]

5 of 6 bolts missing (https://translate.google.com/translate?sl=no&tl=en&u=https%3A%2F%2Fwww.nrk.no%2Ffinnmark%2Fhelikopterulykken_-her-mangler-fem-av-seks-bolter-1.14701672)

Google translate, but you get the major points.
Might explain the EAD on all new AS350 B3e's

[GrayHorizonsHeli]

Looking at the pic they show, there is significant damage to the couplings. More than I have ever seen. And I have dealt with many sudden stoppage instances over the last 17yrs of component overhaul and repair.
I have alot of questions on what I see here, and find it hard to believe that bolts could have fallen out, although it is possible in a bad case of the swiss cheeze holes lining up.

I believe the engine was ripped from the airframe in this incident and gives pause to some of the damage seen as secondary. The reason I say that is because they show the aft driveshaft coupling torn apart, yet the tail rotor looks intact in the one picture. The liaison tube also bears significant secondary damage consistent with forced removal.

Like I said, there is alot of questions still, especially since the ASB came out to look at these bolts. Are they a cause, or is it secondary damage as well.

[wrench1]

Looking at the pic they show, there is significant damage to the couplings.... find it hard to believe that bolts could have fallen out...
Years ago under the Aerospatiale logo there was a "similar" rash of incidents/accidents with the 350/355 driveshaft flex couplings. Don't recall the specifics but believe it was the bolt tensile strength or something else that caused the bolt/nut to lose torque leading to bolt failure. The fix was to replace all the bolts with known good bolts marked with baby blue paint on the heads and a repetitive tq-check and bushing check on the disc packs. Unfortunately it doesnt need the bolts to fall out to have a failure which unfortunately again looks similar to the above pics.

[GrayHorizonsHeli]

this a/c should have the latest mod i think. well beyond the blue head bolts..
there is longer bolts, the 12pt nuts and the higher torque loading now.

if the bolts sheared thats one thing, but if they were loose for so long the nuts came off, or wore thru the bolts enough to disconnect, then theres some serious human factor errors at play from alot of levels

[GenuineHoverBug]

The final report on the investigation of the accident near Alta on the 31st of August 2019 from the Norwgian safety investigation authority (NSIA) was published yesterday.
The translated version is here (https://www.nsia.no/Aviation/Published-reports/2022-02).

"As a result of this investigation the NSIA submits 12 safety recommendations addressed to EASA, CAA-N and Helitrans AS, the helicopter operator. They concern measures to prevent servo transparency, training and safety of commercial sightseeing flights, survival aspects, including crash resistant fuel system and use of helmets, and requirements of lightweight flight recorders."

[[email protected]]

An inexperienced pilot running out of talent while trying to give his pax a fun ride.............a waste of 6 lives.

[Doors Off]

An inexperienced pilot running out of talent while trying to give his pax a fun ride.............a waste of 6 lives.

Another Victim of CIFS (Camera/Crowd Induced FWit Syndrome). Poor bunch. The driver had a moment of CIFS by the sounds of it and they didn’t get away with it. A sad loss.