S92 "unexpected control responses" [Archive]

Apate

31st Dec 2016, 22:19

Your first two sentences use the words "realistically" and "actually" in a vain attempt to justify your argument. Sorry, but you fail.

Two fatal accidents (L2 & EC225) with full independent investigations do not find a root cause. The latest EC225 accident also highlights that HUMS did not provide any indications of an issue, yet resulted in a catastrophic failure with no chance of any survivors.

I'm not going to waste bandwidth drawing the lack of comparison!

I do wish there was a "bullsh1t" coughing emoticon that I could use. :p

The Sultan

31st Dec 2016, 22:52

Mitch,

This has happened a lot more than twice unless there is another tail rotor bearing that fails and requires a run on landing due locked or loss of thrust. I heard of two back six or so years. One in Norway for sure.

The Sultan

Apate

31st Dec 2016, 23:35

So who do you work for? CAA, CHC Silorsky or EASA?
Nope - I don't even work for Sikorsky!

I'm independent and have no vested interest other than complete transparency, my own brother flys these (outwith Europe) and my own son leaves and returns to Aberdeen every 3wks hence my input.
I suggest you move over to another forum. This one is for professional pilots.

SASless

1st Jan 2017, 00:25

I always wondered what would lure Sultan out of hiding.....and once again wonder what works effectively to send him scurrying off with his tail between his legs yet again.

:ugh:

ericferret

1st Jan 2017, 01:42

"I suggest you move over to another forum. This one is for professional pilots."

Since when? That not what the forum heading says.

henra

1st Jan 2017, 09:37

Two fatal accidents (L2 & EC225) with full independent investigations do not find a root cause. The latest EC225 accident also highlights that HUMS did not provide any indications of an issue, yet resulted in a catastrophic failure with no chance of any survivors.

Once you wiped the Foam off your Mouth you should see that there is a very serious failure mode that hasn't been properly fixed. This is a serious issue and shouldn't be taken too lightly. The S-92 has proven to be apparently very difficult/impossible to control with a failed Tailrotor (Cougar accident). They were at low power setting and prepared that something might be bound to fail plus they were over water and still the result was an accident with only one survivor. This is probably due to a pretty big and boxy Fuselage and a rather small tail. Weather vaning effect likely pretty small. So the Tail rotor is extremely critical on this type.
Sikorsky needs to fix this ASAP. We don't need another predictable fatal accident.

Does it warrant immediate grounding? Possibly not. Does it warrant highest urgency on the side of the Manufacturer plus rigorous and tight inspections on the active fleet? Absolutely.

Variable Load

1st Jan 2017, 10:04

This failure was potentially very serious, especially as it appears to have manifested itself to the crew after committal to landing on a deck. Loss of control (fixed pitch) of the tail rotor is something crews practice regularly in the simulator, but not when landing on helidecks.

Other than the event itself, there's very little information out there. We don't yet know the root cause, whether the AD was complied with, how long the bearing has been installed, whether HUMS picked up anything, etc. Hopefully these answers will be available soon.

henra - the Cougar accident was a loss of tail rotor drive, a very different failure to this one. Immediate entry into autorotation is the only way to recover from loss of tail rotor drive. They were not at a low power setting as the Captain decided to increase speed to normal cruise power despite the co-pilot suggesting it was not a wise thing to do. To draw parallels between this current issue and the Cougar accident is not appropriate.

henra

1st Jan 2017, 10:48

henra - the Cougar accident was a loss of tail rotor drive, a very different failure to this one. Immediate entry into autorotation is the only way to recover from loss of tail rotor drive.

I know. I wanted to point out that the S-92 is probably even more difficult to handle with a problem on the tail rotor than some other types due to relatively small vertical area behind cg.

To draw parallels between this current issue and the Cougar accident is not appropriate.Agreed, they are technically not directly comparable. But the Cougar accident gave an indication about the criticality of the tail rotor for the S-92 (or any other big Transport Heli. To avoid any suspicions: The 225 or any other of the big Transport Helis won't behave much different they all have massive fuselages and small tails - The only one with a chance of a somewhat more benign behavior might be the Blackhawk). They had to be prepared that something might break, yet they didn't manage to go into Autorotation quickly enough to make it survivable.

industry insider

1st Jan 2017, 11:02

Only some TRPCS were affected by the 2 ASBs. Neither of the ASBs were applicable to this TRPCS. Sikorsky recommends specific emphasis on utilization of the HUMS Tail Gearbox Bearing Energy Tool. This Tool will detect a PCS bearing that is experiencing degradation.

[email protected]

1st Jan 2017, 11:38

It's all very well practicing TR malfunctions in the sim but is the software modelling in the sim completely representative of the handling of the real aircraft? It is possible to get lulled into a false sense of security by a relatively benign sim - it is, after all, just a big computer game.

SASless

1st Jan 2017, 16:56

albatross

1st Jan 2017, 17:47

None that I know of ...fixed pitch yes....loss of tail rotor drive..No.
I assume someone will be along to dispute this.
Taking cover...you may fire when ready.

I would think that folks would wait for additional info on what actually occured before making expert comments on this particular event. Glad everybody was OK after a shower and underwear change.

henra

1st Jan 2017, 20:31

Name one "Large" helicopter that does not have problems "weather vaping" after a Tail Rotor gives up its assigned tasking?

See my SWAG conclusion that the only 'big' Helicopter where I see a tiny chance that it might remain controllable to some extent might be the Blackhawk when lightly loaded and in minimum power cruise.
Between the 'uncontrollable' ones there might be minor differences how many seconds (if any, depending on phase of flight and weight) remain to enter Auto before it goes pear shaped.

[email protected]

1st Jan 2017, 21:30

Is 'weather-vaping' anything like weather-vaning or is it a new term for those helos that are using e-cigarettes?;)

Mast Bumper

1st Jan 2017, 21:42

The UH-60 series helicopter has in fact a very small vertical stabilizer surface and any sort of t/r drive failure calls for engine shutdown and auto. You can't sustain straight and level flight without t/r drive.
An interesting feature are the t/r pitch centering springs that allow for in trim forward flight at a certain weight and either 40kts or 125kts in case of a t/r control failure.

JohnDixson

2nd Jan 2017, 00:55

Hello Mast Bumper. May I provide some more specific information on this design feature. BTW, this design feature is incorporated into the basic S-92 as well.

Actually, the nomenclature you applied is misleading. In the vertical tail structure of the S-70, and prior to the cables being attached to the tail rotor servos, the two tail rotor control cables are attached to opposite sides of a control quadrant. Each side also has a spring capsule. The idea is that in case one cable is shot away anywhere over the cable run from up forward in the machine, the other cable side of the quadrant remains in tension, against the spring force afforded by the spring capsule on the other side of the quadrant. The output side of the quadrant feeds the servo inputs. Full tail rotor authority remains. A switch in the failed cable side of the quadrant illuminates a cockpit warning capsule. The same basic arrangement is found in the basic S-92 design. It has been combat proven on the S-70.

I might add another design feature of the cross beam tail rotor design in both helicopters: As assembled, the cross beams are of course flat, BUT, the airfoils as attached to the beams do not have their zero lift lines coincident with the flat surface of the beams. The airfoils do incorporate twist, and the built in positive angle of attack of the design facilitates flight between 40 KIAS and 120 KIAS with a reasonable amount of sideslip, with no control input. We flight tested the S-70 with both stages of the tail rotor servos depressurized at the same time, and that was the result. We were almost able to come to a hover ( with rather a lot of force on the left pedal (that force is actuated thru the servo control follow-up link ), but not quite, hence the emergency procedure to perform a run on landing if that dual failure were to occur. For non S-70 pilots: the S-70 TR servos are pressurized by the No. 1 and the Backup Hydraulic Systems ( the backup being the same pump as the main No 1 and No 2 systems, but electrically driven ).

Anyway, as you can see, the tail rotor quadrant and spring capsules are probably not a factor in this event, at least as far as the information posted so far indicates, and I am not privy to any other.

LRP

2nd Jan 2017, 02:04

Name one "Large" helicopter that does not have problems "weather vaping" after a Tail Rotor gives up its assigned tasking?

When One considers all possible Power Demands, Torque Moments, and Airpeeds....I doubt any large helicopter can be shown to be able to cope with such problems.
I know of an instance where an AH-64D has the entire tail rotor blade assembly depart in flight, the aircraft was flown to an airfield and made a roll on landing with no further damage. Just sayin'

SASless

2nd Jan 2017, 11:29

Is 'weather-vaping' anything like weather-vaning or is it a new term for those helos that are using e-cigarettes?;)

"Vaping" is autocorrect for "vaning".

Were you unable to make the intellectual leap to figure that out without a colored pencil Briefing?

By the way.....Happy New Year! Fly Safe when you have to leave that notorious Recliner you are reported to wear out when on shift and not engaged in service to the Realm!

[email protected]

2nd Jan 2017, 12:27

Happy New Year to you too SAS:ok:

Don't do shifts any more, which is wonderful - back to 9-5 instructing.

What a strange auto-correct you have - I thought it was just your age and eyesight letting you down;):)

henra

2nd Jan 2017, 18:12

The UH-60 series helicopter has in fact a very small vertical stabilizer surface and any sort of t/r drive failure calls for engine shutdown and auto. You can't sustain straight and level flight without t/r drive.

Among the current generation of bigger Transport Helicopters it still has about the largest vertical Tail especially if you include the smooth transition to rear part for the fuselage that should also produce some Weather van(/p :E)ing or at least reduce obstruction of airflow to the Tail.

@John Dixson: Are there possibly known cases where it was possible to keep the S-70 at least somewhat controllable in a cruise at least for some time with a failed T/R drive? Personally I would consider that potentially possible? Am I too optimistic?

P.S.: Very interesting information about the clever backup solution for the Tail Rotor control :ok:
That is the good thing that can come from 'Battle proven'.

ring gear

2nd Jan 2017, 23:59

We flight tested the S-70 with both stages of the tail rotor servos depressurized at the same time, and that was the result. We were almost able to come to a hover ( with rather a lot of force on the left pedal (that force is actuated thru the servo control follow-up link ), but not quite, hence the emergency procedure to perform a run on landing if that dual failure were to occur.

Very true John. We used to do the same for training students on the S70 back in the early 90's before we had access to simulators. Pull the APU C/B and then fail the the #1 Hyd system......

Result - both T/r servos without Hyd power.

It worked a treat. Built huge confidence in instructors/students alike in the capability of the S70. Directional control as you got below 40KIAS got far more dependant upon wind/cross wind and gusts than simulators can hope to predict.

You learnt quickly that airspeed was your friend in T/R malfunctions....providing you have a fin with descent camber on it.

Speed/attitude control as speed decayed and the pedals got heavier, was essential. Amazing how only a matter of a couple of knots could make the difference in accurate directional control and a straight and totally manageable landing.

Its this amazing and variable effect that happens in real life that simulators sadly can't faithfully reproduce as Crab said earlier. With fear of being called a heretic, perhaps we need to start to recognise the shortfalls of simulators in realistic training in particular for helicopters and low manoeuvres and adapt training accordingly.

Back to the original thread........Excellent design without a doubt......

As an aside and ref loss of tail rotor drive; I had heard an anecdotal incident back in the late 80's of a UH60 losing total tail rotor drive and his #2 (in the formation) calling the incident as the tail rotor (of lead) came to a complete stop. Lead entered a shallow descent and had a slight right hand turn on to maintain better control. But as I remember they landed OK but am uncertain of the finer points of the termination of the incident. But I was talking to a member involved in the incident....so it couldn't have been too messy.

cheers
RG

JohnDixson

3rd Jan 2017, 15:32

Questions raised by Henra and RG:

Let me add some background ( think I've covered this before but probably in a PM. If so, apologize for the repetition ).

The US Army Request for Proposal for UTTAS had a requirement that the vehicle be able to fly at the speed for best endurance in level flight and at a sideslip angle that was 20 0r 30 degrees ( and I cannot remember which ). Tough requirement, and if you recall the pictures of the huge ( and very cambered ) original vertical tail, that was the reason. After getting the flight envelope opened up, we attacked verifying the tail allowed us to meet the requirement. ( Aside: SA flight test had done a similar program on the original S-58 design. That tail rotor had flapping hinges, which allowed the determination of zero tail rotor thrust to be done fairly easily ). A very long story short, with a good number of frustrating flights, meetings, different technical/instrumentation approaches etc left us unable to determine when we were at precisely zero thrust with the rigid, crossbeam tail rotor. That, in addition to the fact that the huge tail incurred a list of penalties that was significant, led us to make the decision to take a proposal non-compliance on that requirement*. As the company strategy was to take zero exceptions, that was a serious internal issue. Result was that we cut the tail down significantly to what it is today. For those who espouse the position that a tactical helicopter can never have too much tail rotor thrust ( I am in that number ), it was the correct compromise.
*I can't say this with surety, but from the size of it, the Boeing UTTAS did not appear to be configured to meet that requirement either.

Now to Henra's and RG's question. I believe that the data that we did generate during the unsuccessful testing, in addition to a few incidents in the field over the years, the answer is that I am not aware of anyone achieving stable level flight ( yes, with a significant sideslip ) following a TR thrust loss, and thus am of the opinion that the existing emergency procedure ( not aware it ever changed ) is correct. RG, I will bring your note to the attention of the now retired test pilot who took over the UH-60 program and who has an excellent memory. Perhaps we can close that loop.

Good posts.

Marv

3rd Jan 2017, 21:28

Following up a post by Industry Insider, can anyone explain the Sikorsky "HUMS Tail Gearbox Bearing Energy Tool"? Is it part of a routine ground station analysis? Does it gather sensor data independently of accelerometers?

The Sultan

3rd Jan 2017, 23:15

Marv, (sorry)

It is a condition indicator looking at a spectrum of vibration at discrete frequencies or over a specific broad frequency range. As bearings fail or are loaded abnormally the discrete or broadband magnitude/energy increases. Unless the HUMS accelerometer is actually at the bearing these signs are not present and the fault is not detectable.

The Sultan

EESDL

3rd Jan 2017, 23:21

Don't write-off FSTDs just yet.
They can prove very useful if given the right data.
The problem of course is finding someone with a wheelbarrow big enough to carry the Cahoonas of the pilot carrying out the test program.
The recent developments in modelling wind turbulence is a good example in improving FSTD fidelity.

Marv

4th Jan 2017, 00:04

Thanks Sultan, do you know if there are conventional HUMS alerts (amber and red) associated with the tail rotor pitch change shaft bearing condition indicator? i.e. a way to categorize a bearing as 'normal' or 'abnormal'?
Marv

malabo

4th Jan 2017, 05:55

So it is two questions: are all operators following the OEM recommendation to use the HUMS tailrotor gearbox bearing tool, and would live or more frequent monitoring have caught this before the excitement on the deck.

How was the aircraft recovered to shore?

ring gear

4th Jan 2017, 06:32

John, the loss of T/R drive anecdote that I had heard did not achieve balanced or prolonged controllable flight. From recollection they had to enter a lowish power descent with right turn and I would guesstimate some degree of slip but personally uncertain.......but importantly ....it bought them time so say a few Chinese expletives (ie "ahh F..k") and to make a few decisions and pull off a relatively safe landing/termination with all on board safe as I recall...

I know...growing old ain't for the faint hearted...

Cheers
RG

lowfat

4th Jan 2017, 09:26

The S92a hums system New and old does have green amber red indicators as in other systems.
It also has a "toolbox " which in the early hums you had to upload separately in the later it is done with the main download of the card.
In the tool box is specific programs which look at tail gearbox bearing energy, tail rotor dis-bond, Mgb foot skew and engine drive shafts.
These programs give you another green or red indicator to simplify and speed up hums analysis of critical previous problem areas.

roundwego

4th Jan 2017, 13:23

And some others

https://wpcluster.dctdigital.com/energyvoice/wp-content/uploads/sites/4/2017/01/heli-5.jpg

https://wpcluster.dctdigital.com/energyvoice/wp-content/uploads/sites/4/2017/01/heli-1.jpg

https://wpcluster.dctdigital.com/energyvoice/wp-content/uploads/sites/4/2017/01/heli-4.jpg

malabo

4th Jan 2017, 14:45

Mitchaa - It is my understanding that HUMS was effective with a warning in this case

I need help with your logic...your helicopter is almost spun off a deck in a near catastrophe. Surely if the HUMS was effective in warning then the aircraft would not have made that last flight to the rig.

SASless

4th Jan 2017, 15:08

Close Calls do not count statistically.

I would say the Crew deserves a "Well Done! for getting the aircraft onto the Deck!:ok:

albatross

4th Jan 2017, 15:46

Looking at the deck there may be a hard landing check in order.
Well done that crew in anycase.

henra

5th Jan 2017, 08:35

I would say the Crew deserves a "Well Done! for getting the aircraft onto the Deck!:ok:
+1.

Plus the relatively wide track of the main gear of the S-92 probably was a good thing in this case as well. Had it fallen on its side the outcome might have been different.

domperry

5th Jan 2017, 13:13

It doesn't add much, but the AAIB says it is now sending a team to investigate. (An hour earlier, it said merely that it was looking into reports of an incident.)

albatross

5th Jan 2017, 13:36

Yes Henra the 92 is like a flat iron compared to some other helicopters.

212man

5th Jan 2017, 14:27

Interesting to see the nosewheel at 90° - I wonder what effect it would have had if it had been lockable? Might have either resisted the rotation, or exacerbated the tendency to roll over!

Concentric

5th Jan 2017, 16:16

If there was some loss of tail rotor control, would the canted tail rotor and its complex yaw/pitch coupling of control inputs have compounded attempts to control the aircraft and get it planted onto the deck? A loss of lift at the tail might explain the slice in the aluminium alloy decking, seen in 2 of the photos, roughly radial to the landing circle.

The crew did well to keep it on deck, once it had made initial contact, and not hit the nearby crane. Or worse.

albatross

5th Jan 2017, 16:16

Just speculating but are the cuts in the deck caused by the wheel rim?
If so the tires must have nearly been rolled off the rim.
Must have been an interesting few seconds.

Pablo332

5th Jan 2017, 16:18

Nice to see a happy ending to someone’s really really bad day.

albatross

5th Jan 2017, 16:20

They don't call them poopy suits for no good reason!
212 man: not an expert by anymeans but I suspect that the ability of the 92 nose gear to castor was beneficial, in this case, to keeping the aircraft upright. A locked nosewheel would, I think, have contributed to any rolling movement. I wonder how much the aircraft actually tilted. Thoughts?

[email protected]

5th Jan 2017, 18:37

If you allow the aircraft to yaw freely (castoring nosewheel) then I wonder if it has more tendency to roll in the opposite direction to the turn than if the nosewheel is sliding (resisting the yaw) - just a thought.

Fareastdriver

5th Jan 2017, 19:44

When landing a heavy plank wing with a steerable nosewheel when you let the nose drop and there is substantial weight on the nose wheel then the cams will ensure that you can only control its direction with nosewheel steering. In a severe crosswind this can lead to some deft fiddling with the tiller to keep it straight.

In this case I would have thought that the castoring nosewheel would have been a help rather than a hindrance.

JMACDAS

5th Jan 2017, 23:53

Think there will be some concern about the deck surface failing. Wonder if the CAA will have some changes to CAP 437 regarding 'punching'.

jimf671

6th Jan 2017, 01:01

Energy has to go somewhere: 12 tonnes flailing around. In this case, a significant amount has gone into deforming the deck.

Where else do you want it to go? We can have glass hard deck but then it's more likely that energy will carry the aircraft over the edge.

SASless

6th Jan 2017, 01:19

Crab,

Is there a difference between the reaction of an aircraft to the Castoring Wheel being in front of the mast or behind the mast as say in a 92 and a Wessex/61.....re Tipping Tendency?

JulieAndrews

6th Jan 2017, 03:10

Is the 92 operated to PC1 or still the PC2DLE fudge?
From all accounts very fortuitous (!) the failure happened when it did and well done to the crew.

NOT SAYING IT IS THE CASE HERE - but got me thinking - intrigued on bearing load factors with a regular practice I have seen - almost a 'snatch' application of power as crews decelerate with min torque set (quickstop-esque) then apply power just before decision to 'make' the DPBL - albeit with a pinch of salt. Evident from 'newcomers' from other companies.
Cannot help but feel such a manoeuvre does not help situation.
Does CHC track such parameters on HOMPs - I ask because it is something our customer insist we monitor.......

twisted wrench

6th Jan 2017, 08:50

Julie Andrews: Yes they do, for CHC they use FDM ( Flight Data Monitoring) to meet the requirements of HOMP.

[email protected]

6th Jan 2017, 09:50

Sasless - I don't think there is a difference - I was thinking about ground taxiing a 365 (castoring nosewheel) and how it rolls out of the turn when you yaw it. The same used to happen in the Wessex/Sea King (castoring tailwheel) - one Wessex student of mine many years ago got us up on two wheels (left main and tail) being a little spirited with his first ground taxiing!

212man

6th Jan 2017, 10:32

Is the 92 operated to PC1 or still the PC2DLE fudge?

How would that be relevant to the incident?

terminus mos

6th Jan 2017, 12:18

the 92 operated to PC1 or still the PC2DLE fudge?

Julie, obviously you have never flown one or looked at the RFM.

finalchecksplease

6th Jan 2017, 13:11

I can't see either, like 212man, how PC1 or PC2DLE in this case is relevant.

Edited to take out comment "terminus mos: you clearly don't know 212man's background do you?" because I misread his post. Thanks for pointing this out 212man.

212man

6th Jan 2017, 13:55

terminus mos: you clearly don't know 212man's background do you?

I think you'll find he does (he may even have had dinner with me in Brunei ;)) and I think he was referring to Julie's comments

JulieAndrews

7th Jan 2017, 03:14

sorry gents - should have been a bit clearer.
I'm thinking about how different profiles require different applications of power and the individual's 'individualist' approach to applying them.
I have been sat in seat where pilot thought a quickstop and 'snatch' of power at the end was a good way of approaching and thought the geartrain would not 'like' it.
thank you for clarifying PC1 profile and HFDM following.

Groquik

10th Jan 2017, 09:29

Breaking: Sikorsky grounds all S-92 helicopters after North Sea platform incident (https://www.energyvoice.com/oilandgas/north-sea/128451/breaking-sikorsky-grounds-s-92-helicopters-north-sea-platform-incident/)

Written by Lee McCann and Niamh Burns - 10/01/2017 10:09 am

All North Sea helicopter flights have been grounded today over safety fears.

Sikorsky S92 helicopters have returned to base following a probe into a recent incident on a North Sea platform.

It’s understood the request to ground the S-92s was at the request of Sikorsky.

A spokesman for Aberdeen International Airport said: “We are aware of a safety alert that has been issued for all S92 helicopters and are anticipating a potential impact on helicopteroperations over the next few days until essential maintenance has been carried out. We will support the operators as much as possible through this disruption.”

The move comes after an incident involving an S-92 on a North Sea platform last month.

The helicopter flight had been making a shuttle flight between Total’s Elgin platform facilities and West Franklin, around 130 miles off the coast of Aberdeen.

Images later emerged of the damage to the platform as the flight attempted to land with nine passengers and two crew on board.

A source at the time said the S-92 took “gouges out” of the helideck, damaged its wheels and spun on the deck of the West Franklin when it was forced to land.

The decision to ground S-92s comes after Super Pumas were banned in the wake of a North Sea helicopter crash off the coast of Norway which killed 13 people on April 29th last year.

roundwego

10th Jan 2017, 09:52

Fleet of 225's seen heading up the A90 to Aberdeen.

MoateAir

10th Jan 2017, 09:59

Sikorsky grounds S92 helicopters for checks after incident - BBC News (http://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-38568615)

rrekn

10th Jan 2017, 10:11

And HUMS close monitoring of the Tail Rotor Pitch Change Bearing is now required.

Sikorsky taking the lead from Airbus?

roundwego

10th Jan 2017, 10:21

Anyone got a copy of the Safety alert /SB to share?

pitch horn

10th Jan 2017, 11:30

Can we assume that this grounding includes SAR S92's ?

212man

10th Jan 2017, 11:40

Can we assume that this grounding includes SAR S92's ?
It's not a grounding - it's a once off inspection followed by increased HUMS surveillance (more frequent downloads). Yes, SAR aircraft must comply too.

S92A Alert Service Bulletin - HeliOffshore (http://helioffshore.org/s92a-alert-service-bulletin/)

HeliComparator

10th Jan 2017, 12:21

Well I'd say it is a grounding - a short term one until some maintenance action is carried out. The aircraft is grounded in the interim.

I guess it depends on what sort of a spin you want to put on it. If it was a 225 in the frame, everyone would be clamouring "Grounding"!

212man

10th Jan 2017, 12:31

I guess it depends on what sort of a spin you want to put on it. If it was a 225 in the frame, everyone would be clamouring "Grounding"!

Not sure it needs 'spin' - it's an ASB, so requires actions within a specified timeframe, like all ASBs......

212man

10th Jan 2017, 12:39

Are these flights on hold, S92s, or is it weather?
07:00 07:11 77D REPSOL SINOPEC RESOURCES UK LTD 08:50 Landed None
07:00 07:14 48C CONOCO PHILLIPS PETROLEUM COMPANY U 08:41 Landed None
07:00 07:34 45B REPSOL SINOPEC RESOURCES UK LTD 08:09 Landed None
07:10 07:23 51E REPSOL SINOPEC RESOURCES UK LTD 08:21 Landed None
08:00 ... 43G B.G. INTERNATIONAL (CNS) LIMITED 10:50 Flight on Hold EGPD / LOMON / EGPD
08:15 ... 63J DANA PETROLEUM PLC 10:25 Flight on Hold EGPD / TRIT / EGPD
10:15 ... 45K REPSOL SINOPEC RESOURCES UK LTD 12:25 Flight on Hold EGPD / TARTA / EGPD
11:00 ... 62Q CONOCO PHILLIPS PETROLEUM COMPANY U 17:30 Delayed EGPD / BRITP / EGPD
11:00 ... 56N MARATHON OIL U.K. LLC 14:35 Flight on Hold EGPD / BRAEA / BRAEB / EBRAE / EGPD
11:00 ... 51M REPSOL SINOPEC RESOURCES UK LTD 13:25 Flight on Hold EGPD / NORA / EGPD
11:00 12:55 74R REPSOL SINOPEC RESOURCES UK LTD 14:50 Outbound EGPD / BUCHA / EGPD
12:00 ... 43T B.G. INTERNATIONAL (CNS) LIMITED 14:40 Flight on Hold EGPD / EVER / EGPD
12:30 ... 74A REPSOL SINOPEC RESOURCES UK LTD 16:25 Delayed EGPD / BUCHA / EGPD
13:30 ... 76B REPSOL SINOPEC RESOURCES UK LTD 16:25 Flight on Hold EGPD / FUL / EGPD
14:00 ... 48E CONOCO PHILLIPS PETROLEUM COMPANY U 16:55 Flight on Hold EGPD / JASM / EGPD
14:00 ... 45D REPSOL SINOPEC RESOURCES UK LTD 16:20 Flight on Hold EGPD / PIPER / EGPD
14:30 ... 77G REPSOL SINOPEC RESOURCES UK LTD 17:45 Flight on Hold EGPD / CLYDE / AUKA / EGPD
15:30 ... 48G CONOCO PHILLIPS PETROLEUM COMPANY U 18:25 Flight on Hold EGPD / CORIV / EGPD
16:00 ... 58H PETROFAC FACILITIES MANAGEMENT LTD 18:20 Flight on Hold EGPD / FPF1 / EGPD
17:30 ... 51L REPSOL SINOPEC RESOURCES UK LTD 20:15 Flight on Hold EGPD / XSAB / NORA / EGPD
18:00 ... 62U CONOCO PHILLIPS PETROLEUM COMPANY U 20:30 Flight on Hold EGPD / BRITP / EGPD
18:00 ... 51K REPSOL SINOPEC RESOURCES UK LTD 20:25 Flight on Hold EGPD / XSAB / EGPD
18:30 ... 74B REPSOL SINOPEC RESOURCES UK LTD 20:25 Flight on Hold EGPD / BUCHA / EGPD

Camp Freddie

10th Jan 2017, 12:40

http://www.oilandgaspeople.com/news/12033/north-sea-helicopter-operations-grounded-with-immediate-effect/

212man

10th Jan 2017, 12:59

..upon receiving the bulletin took the decision ...

Not much 'decision making' available in the ASB

Compliance is essential.

HeliHenri

10th Jan 2017, 12:59

.
From HeliHub : HeliHub.com Prefect storm ? Sikorsky grounds S92 (http://helihub.com/2017/01/10/sikorsky-grounds-s92/)
.

John R81

10th Jan 2017, 13:58

BBC news today (http://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-38568615) Sikorsky grounds S92 helicopters for safety checks after incident as a "precautionary measure".

John R81

10th Jan 2017, 14:00

Just shows how far behind the curve our news services are

ericferret

10th Jan 2017, 14:26

I would say there is a decision process to be made. It is a given that on oil and gas these aircraft will be grounded. However a number of aircraft are engaged SAR and as bulletins are not mandatory even if given Alert staus I suspect that in a real emergency they will launch. At time of writing I cannot find an Emergency AD from either the FAA or EASA which would be mandatory.

RVDT

10th Jan 2017, 16:39

as bulletins are not mandatory even if given Alert staus I suspect that in a real emergency they will launch. At time of writing I cannot find an Emergency AD from either the FAA or EASA which would be mandatory.

Depends on the maintenance statement and the AMM.

albatross

10th Jan 2017, 16:48

Well, considering the microscope helicopters operate under nowadays and sensationalistic headlines in some media outlets, perhaps it was a wise idea to immediately cease 92 ops until the check had been completed.
Were any aircraft turned around and RTB while enroute offshore or did they complete their trips?

SASless

10th Jan 2017, 16:58

If it was a 225 in the frame, everyone would be clamouring "Grounding"!

I suppose some would argue the 225 is not grounded currently....despite reality.:ugh:

HeliHenri

10th Jan 2017, 17:23

I suppose some would argue the 225 is not grounded currently....despite reality.:ugh:

Stop hitting your head, it hurts. ;)

Around 100 AH225 are fliyng every day.
.

c53204

10th Jan 2017, 17:39

albatross

10th Jan 2017, 18:23

JOKE. Well..for one thing...everytime we had a chip light..or a gen failure or any other minor issue it did not get immediately reported in the media as "Helicopter Emergency Landing barely misses local Orphanage, Hospital and house with cute puppy inside! 100s traumatized!" Film at 1100. END JOKE

Nowadays any issue gets reported in the media and, unfortunately "Perception is reality".

Sevarg

10th Jan 2017, 18:35

C52304, I think it´s fair to say that we are now entering a time when helicopters are going straight into civil use. Both the types you mentioned had many hours (and problems) with the military.When problems were found and corrected.

jimf671

10th Jan 2017, 18:45

c53204, if you have never seen a problem with those older types then you have been a whole lot luckier than some of us.

Can I sit beside you next time?

Fareastdriver

10th Jan 2017, 19:57

I seem to remember two S61 gearboxes burning out. One on the North Sea and the other an SAR machine. Engine run down and settling onto the back of a supply boat. A calm sea state was regarded as a good 61 ditching day.

The S76 threw a blade at Aberdeen and we flew next day with tie wraps holding the blade bearings in. When the turbines started bursting a ring of armour plate was placed around them to stop them damaging the luggage.

The old Puma 330 had problems with pitch horn bearings, inclined shaft hinges and a fatal at Aberdeen where an engine run down when the other was pulled back for training.

For the inaugural flight of the 234 they placed tea and biccies for the passengers, there being a cabin attendant. At the appointed time the locker was opened and there was a sea of writhing crumbs. Again a calm sea was 234 water taxiing time to get to the Shetland basin. A 234 was also responsible for the greatest loss of life.

The 332 started going through gearboxes like a lottery winner. There must have been three in the air at the same time in the hanger. Rotor heads cracking offshore, innumerable spurious fire warnings and again an inclined shaft hinge pin coming out. It took about two years to solve all the problems.

Alan Bristow, an ex test pilot, used to create at the helicopters companies because he did not know why the users had to do all the advanced test flying for them; this covered all companies.

It happened so often in those days that it didn't make the papers.

Hot_LZ

10th Jan 2017, 21:58

C53204,

The types you have mentioned were no doubt during military time. As a passenger you are very much kept out of the loop of problems going on. You would never subsequently be informed not was there any intention to. It's a different game in the civilian world when someone's paying for the flying.

Morale of the story being you got away with a lot more in the military.

LZ

henra

10th Jan 2017, 22:08

And HUMS close monitoring of the Tail Rotor Pitch Change Bearing is now required.

Sikorsky taking the lead from Airbus?

Anyway: Thumbs up! :ok:
That is the right approach to be rather cautious than sorry! It won't have too much impact to do these inspections and it makes sure a potentially preventable accident does not occur. That is exactly the pro- active approaching of a known issue that Airbus/EC should have done after the first occurance of each - the Rotor separation and the bevel gear shaft. Would have saved a number of Lives and them an economic disaster.

Thridle Op Des

11th Jan 2017, 02:12

...and to add to the SA330J story, the same inclined drive shaft cover issue as the AS332L but with less spectacular results, it only opened out to within 1" (metric) of the tail rotor in SUM. Lesson learned not adapted on subsequent variant.

212man

11th Jan 2017, 07:19

A very simplistic question from someone who has many pax hours in helicopters. Is it fair to say that mechanical failures are happening more on helicopters? If so, is this because of modern design - i.e. Lighter components to save weight/increase payload, etc, etc.

All my hours in Sea Kings, Pumas, I never remember a Main gearbox, bearing, or tail issues, ever - certainly not 'accident' or grounding issues.
Mostly the advent of social media and the 24 hours news culture that demands instant answers. The 70s, 80s and 90 are littered with serious incidents/accidents - many involving that old favourite, the S61! Some UK AAIB examples here: https://www.gov.uk/aaib-reports?keywords=&aircraft_category%5B%5D=commercial-rotorcraft&report_type%5B%5D=formal-report&date_of_occurrence%5Bfrom%5D=1971&date_of_occurrence%5Bto%5D=

TorqueOfTheDevil

11th Jan 2017, 12:19

However a number of aircraft are engaged SAR and as bulletins are not mandatory even if given Alert staus I suspect that in a real emergency they will launch. At time of writing I cannot find an Emergency AD from either the FAA or EASA which would be mandatory.

...yet the SAR aircraft were grounded (no doubt briefly) as well as the O&G ones.

rrekn

11th Jan 2017, 13:04

Anyway: Thumbs up! :ok:
That is the right approach to be rather cautious than sorry! It won't have too much impact to do these inspections and it makes sure a potentially preventable accident does not occur. That is exactly the pro- active approaching of a known issue that Airbus/EC should have done after the first occurance of each - the Rotor separation and the bevel gear shaft. Would have saved a number of Lives and them an economic disaster.

Agreed, but again we seem to be relying on HUMS as an airworthiness assurance tool, rather than the reliability tool is was designed as. If you can't say that the bearing will last for 3 hours, it shouldn't be flying.

HUMS didn't find the EC225 Epicyclic failure...

212man

11th Jan 2017, 13:04

No doubt also using the option of a 6 hours HUMS download interval that SIK are offering...

212man

11th Jan 2017, 14:08

Special Bulletin out from AAIB: https://assets.publishing.service.gov.uk/media/587640a9ed915d0aeb00013f/AAIB_S1-2017_G-WNSR.pdf

[email protected]

11th Jan 2017, 14:29

Holy sh*t!!!!!! Boy were those guys lucky. Does their diary read: note to self, if in doubt there is no doubt - shut down and get it checked?

Pablo332

11th Jan 2017, 14:42

Nice to see a manufacturer dealing with an Authority in a manner that promotes transparency and safety for a change. If only it was like this all the time.

FC80

11th Jan 2017, 15:29

Interesting that HUMS showed out of limits before the flight commenced but this wasn't picked up.

Surely some kind of automatic 'red light' should pop up on the HUMS interface as opposed to relying on someone going in to check every single possible parameter for exceedances?

FleurDeLys

11th Jan 2017, 16:55

Special Bulletin out from AAIB: https://assets.publishing.service.gov.uk/media/587640a9ed915d0aeb00013f/AAIB_S1-2017_G-WNSR.pdf

Howcome, with a major (potentially catastrophic) loss of control, it took more than a week for the AAIB to be informed of the incident?

jimf671

11th Jan 2017, 17:57

The Sikorsky S-92, like its competitor the AH H225, is a good modern aircraft with a safety record well ahead of many of its predecessors. However, I do not think it is so perfect that it can sustain the pressure of being the sole or main large helicopter in O&G crew change. If it is doing most of the work then it will have most of the accidents. There needs some solution that spreads the load before that scenario plays out in the most frightening way.

Hueymeister

11th Jan 2017, 23:56

So if the tail rotor pitch goes to a min-power-ish setting, what sort of run on speed does that equate to?

Evil Twin

12th Jan 2017, 02:33

So if the tail rotor pitch goes to a min-power-ish setting, what sort of run on speed does that equate to?

That would very much depend on AUW I'd imagine

212man

12th Jan 2017, 06:32

So if the tail rotor pitch goes to a min-power-ish setting, what sort of run on speed does that equate to?

From memory, the BHL GoM aircraft ran on at about 80kts and the Norsk one at 55 kts.

Non-Driver

12th Jan 2017, 07:47

Howcome, with a major (potentially catastrophic) loss of control, it took more than a week for the AAIB to be informed of the incident?
Agree, this should have been treated as a catastrophic loss right from the start for investigation purposes. It was only extreme luck and crew reactions that prevented loss of life.

500e

12th Jan 2017, 11:16

A few years ago I was taken to task for suggesting a cockpit warning regarding excedances, & told that pilots would not be able to understand the data, seems the engineers have only a loose grasp as well.
As FC80 says & I suggested
Interesting that HUMS showed out of limits before the flight commenced but this wasn't picked up.
Surely some kind of automatic 'red light' should pop up on the HUMS interface as opposed to relying on someone going in to check every single possible parameter for excedances ? :ugh::ugh:

Hueymeister

12th Jan 2017, 11:22

Is the HUMS data not streamed live back to Ops in the case that anything untoward show up?

80kts is a quick run on!:uhoh:

FC80

12th Jan 2017, 11:41

500e - I actually noticed after I posted that there is a footnote in the report that basically says that there is an upgraded HUMS groundstation available that automatically flags up any problems but this version wasn't being used.

It does seem like a rather large hole in the Swiss cheese to not have had that from the beginning. I've seen some of the kind of data HUMS spits out and it's not (as far as a stupid pilot like me is concerned at least) always easy to interpret.

Huey - no, HUMS parameters are downloaded to a data card which is then removed from the A/C at the end of the flight and downloaded again onto an engineering groundstation. Live streaming would be impractical and hugely expensive right now I'd imagine.

Non-Driver

12th Jan 2017, 12:34

Huey - no, HUMS parameters are downloaded to a data card which is then removed from the A/C at the end of the flight and downloaded again onto an engineering groundstation. Live streaming would be impractical and hugely expensive right now I'd imagine.
Certainly in the big jet world, things have moved on a touch. Quick Access Recorders for FDM have been replaced by Wireless Ground Links (commonly known as WiGgLes) triggered by weight on wheels and/or shutdown. Anywhere with wifi internet or data SIM connectivity means a data packet is automatically transferred per sector. Granted on Rotors Running rig turnrounds that doesn't give much time, but by the time of the next landing critical info could be conveyed. All of course assuming the important "criticial event" triggers are set up and the home base station has full analytical capability. Not quite real time but better than end of working day download.

maxwelg2

12th Jan 2017, 13:22

As a PAX I'm surprised that an operator would "miss" a HUMS threshold exceedance on the TRPCS, especially in light of the previously issued AD # 2016-24-51, dated November 18, 2016.

I appreciate that the aircraft can only be designed and operated within budget constraints, but a TR failure on an approach to a helideck is not very conducive to the drivers or SLF. What price do the operators really place on safety...

The fact that this failure mode appears to have surfaced several times before, and with it being such a critical part of the machine's airworthiness, would have IMO warranted a much more higher profile and proactive maintenance and inspection regime, including HUMS threshold monitoring.

We have been relying on this type to get to work since 2006 over here in Newfoundland, we had CGR491 on March 12, 2009 which could have been avoided if the failure mode from Broome in July 2008 had been correctly diagnosed and an AD for immediate stud change out applied. I sincerely hope that lessons are learned here this time round, as somebody earlier had said this was a large hole in the Swiss cheese.

Fareastdriver

12th Jan 2017, 13:34

80kts is a quick run on!

Even with the minimum ply tyres that helicopters are equipped with 80 knots touchdown is peanuts as far as the undercarriage is concerned.

SASless

12th Jan 2017, 13:39

As mentioned earlier two bad events occurred post detection by HUMS equipped aircraft, yet each aircraft was signed off as "Serviceable".

As a perfect helicopter is impossible to design,build, and maintain...there needs to be a detection system to assist in ensuring faults being found and reported ergo HUMS being invented and incorporated into modern Helicopters.

What good is HUMS if its successful detection of a problem is not properly used in a timely fashion?

Half assed measures undo every Safety Program.

HUMS alone is not the last word on the airworthiness of an aircraft but it sure goes a long way in making such a determination.

Why can HUMS not be modified to provide a Cockpit warning of some kind should a fault situation be detected?

Why can the ground station not be modified so that n immediate fault message not be provided in real time to Engineering?

If airlines can live stream engineering data the it would seem the helicopter industry could do the same in specialized operations such as the North Sea and Gulf of Mexico?

Yes....that costs money....probably a lot of money....but at what point does those costs are offset by preventing aircraft losses that kill a dozen or more people per event?

Lonewolf_50

12th Jan 2017, 14:50

SASless: are you familiar with the opposite problems in HUMS, false positives? My experience (about 2 decades ago) with a much older version of a system like the HUMS was plagued by that. I am not sure what the current state of play is with HUMS and various similar systems, but let's not pretend that it offers omniscience.

Look at the human factor here: if a given HUMS type of system is low confidence as perceived by the people using it, then there is ample opportunity for their frustration with such a system to believe that yet another false positive has confronted them.

Not saying that this is the case regarding this incident, nor the previous loss in Norway, but it's a human factor that should not be swept under the rug.

FC80

12th Jan 2017, 15:06

TorqueOfTheDevil

12th Jan 2017, 15:18

at what point does those costs are [sic] offset by preventing aircraft losses that kill a dozen or more people per event?

Beat me to it! As an aside, was it not the in-flight transmission of eng data which gave clues as to which way MH370 went after all other contact was lost?

jimf671

12th Jan 2017, 15:21

... Not saying that this is the case regarding this incident, nor the previous loss in Norway, but it's a human factor that should not be swept under the rug.

No room left under the rug with this one since the same thing happened with the pilots and the aircraft behaviour. They were presented with what we now know was evidence of impending failure but in the circumstances they were able to assure themselves that the effect was typical of local air conditions.

Lonewolf_50

12th Jan 2017, 16:01

No room left under the rug with this one since the same thing happened with the pilots and the aircraft behaviour. They were presented with what we now know was evidence of impending failure but in the circumstances they were able to assure themselves that the effect was typical of local air conditions.
Jim: all points taken and accepted. Our hindsight is 20-20, but your point on the human factors piece of the pilots diagnosing the yaw/controllability excursion as something else (since there were not other cockpit indications?) fits my general idea.

Regarding that thing ...

"huh, what's with the controls here, what just happened"

I am having a flashback to a 1982 SH-2F accident. A control position/controllability issue arose and the pilots landed. They tried to figure out what was wrong and reset the boost/flight control system, thinking it to be an electronic anomaly. (Occasional hiccups in the flight control system, electronic sub systems, wasn't that uncommon). They decided to take it back to the hangar to get it looked at.

As it happened, when they lifted up to air taxi there, the helicopter came apart. (A guy in my squadron saw it happen; he was at the other end of the airfield awaiting clearance to take off and happened to be facing so he had a front row seat).

It was later discovered that the azimuth (for an H-2 that's basically the swashplate) had come untorqued and when the load to pick up hit it, it separated. A novel failure, to say the least, but a nasty one. As you can imagine, parts went everywhere. One fatality, the crewman, trapped in the burning wreckage because the radar came off the rack and pinned him.

Some changes to various flight control malfunction/emergency procedures was made, and the Navy/OEM got together to make some improvements to the azimuth/swashplate to prevent that happening again. From memory, I don't recall that particular issue ever came up again.

[email protected]

12th Jan 2017, 16:21

Any indications of how many (if any) of the bearings that have been checked are in the 'distressed' condition shown in the picture (even the early stages of 'distress')?

Was this a design issue (probably not since we haven't had a spate of similar failures), a manufacturing failure (similar comment unless there has been a bad batch) or a maintenance issue (poor installation, poor technique, wrong tools etc)?

jimf671

12th Jan 2017, 19:13

It's late, it's January and it's dark, cold, windy or snowing, and in some locations all of those, around the North Sea, and the Barent, but there are plenty S-92 out there right now making up for lost time.

Safe flying to all.

SASless

12th Jan 2017, 20:57

Lone,

Unless the Human Interface in the system does as it is supposed to do by Procedure, Policy, Practice, and Experience....no system devised will be effective.

Case in Point is the Cougar Tragedy....had the Captain followed the Checklist Procedure (which the Co-Pilot advocated to do...) then there would have been a much different outcome to that sad affair.

To validate your point about False Indications....you probably recall the Blade BIM system on the Sikorsky Iron....which had both a Blade Indicator and an In-Cockpit Warning Light. The Blade Indicator was prone to give false indications occasionally....but the Cockpit Warning was notoriously prone to lie. My outfit removed the Cockpit system and went with a visual inspection of the Blade BIM's every time we shut down and set a Time Limit between Blade Checks.

There will always be False Fault Indications I would guess...but a False Positive is an inconvenience or nuisance whereas a False Negative (No Warning) could be quite deadly.

As to your SH-2 Crew....being on the ground at their maintenance base....shutting down and calling for a Tech or even a Tug would have prevented that Fatality.

Did not the USMC not lose a HueyCobra at Twenty Nine Palms not so long ago from a similar decision to continue flight following some kind of fault warning rather than land out and call for technical assistance?

albatross

12th Jan 2017, 21:11

Oh the number of test flights I have done on the XXX ( not the 92 ) helicopter because of false vibration excedences..Drag it into the hangar, tighten all the accelerometers ..off on a nice 30-40 minute test flight ..return.

Lonewolf_50

12th Jan 2017, 21:11

As to your SH-2 Crew....being on the ground at their maintenance base....shutting down and calling for a Tech or even a Tug would have prevented that Fatality. SAS, that's the problem with symptoms looking like one thing and being something else. Having a landing area being separated by a body of water from the hangar area. To be sure, our wing commander raised the same question you did: why not shut down and get a tow back? The answer was,
"we trouble shot the malfunction we thought we had"
From boost off up, add boost/lateral coupler/ASE/AFCS -- each sub system had its little quirks that occasionally made one have to set her down and reset the system. The whole community (both coasts) were quite surprised at that particular failure.

As to the BIM, yeah, familiar.

Satcomm

13th Jan 2017, 02:35

From the report:
A routine download of the HUMS was performed on the evening of 27 December 2016 and the helicopter was released to service. A detailed analysis of the data, conducted after the accident, showed that the Tail Gearbox Bearing Energy Analysis limit had been exceeded on 27 December 2016.

CHC and it engineers are taking quite a grilling but I'm not sure that the report is clear enough to justify that. It does not state that they missed obvious limit exceedances or knowingly returned an unserviceable aircraft to service. It does however states that a "detailed" (not routine) analysis was conducted after the fact and it showed the aircraft exceeded the limit. This detailed anaylsis was probably conducted by a team of engineering/programming personal at Sikorsky. Also probably using different software/hardware then what was available to the engineer or operator at the time. It's a shame that these initial reports leave so much interperation. They seem to create more questions then provide answers. Kinda reminds you of the last major accident where the blame was quickly put on the maintenance staff .... Everything from rumoured test flights to washers/pins sitting in a guys tool box.

The imd_ground station, from what I understand, is what most are still using. The Sikorsky created Tool for monitoring this item is a pretty straight forward go-no go tool. Open the toolbar, look at the trend, insure it's not on the rise and that it's below the limit. Beyond that, there is a big green box with the letters "OK" in it if all is good. You don't really have to dig hard to find the info. There are several items that are closely monitored with their own deicated tools and I find it hard to believe that any operator are ignoring these items. Now, if the info inside the tool is not correct or as accurate as it could be, that's a manufacture issue.

Geoffersincornwall

13th Jan 2017, 06:00

A good ECL will contain, in addition to the basic drill/procedure, supplementary information:

1. Immediate actions - There always will be situations that demand an immediate response from the handling pilot, autorotation following double engine failure for one. The problem is the regulators seem not to understand this need consequently IMMEDIATE ACTIONS may be missing from the RFM.
2. Subsequent Actions - Every malfunction has a context and therefore warrant some guidance based on the extensive experience gained on this or other similar types. Over optimistic assertions in the RFM may be technically correct but if you think I am going to 'CONTINUE FLIGHT' with both batteries indicating 'HOT' then you can think again. 'Subsequent Actions' are an opportunity to recognise that simple cockpit warnings may not be telling the whole story. Wisdom can be passed on via comments and suggestions made under this heading.
3. Considerations - The RFM based QRH is essentially 'generic' and may not cover some specific role equipment fitted to your aircraft. Any and all other relevant advice can be included under 'considerations'.

Unless and until the regulators insist on something other than a brand new, factory-fresh helicopter situated downwind in the traffic pattern at the flight test facility being used for the production of emergency procedures we are unlikely to see the smaller organisations (who cannot afford to produce their own ECL) benefit from the collective wisdom of the helicopter community.

G.
Sim Trainer ? Sim Trainer (http://www.simtrainer.co.uk)

ShyTorque

13th Jan 2017, 06:36

UK NOTAM in place regarding worldwide grounding of S-92. Any update?

[email protected]

13th Jan 2017, 09:21

Geoffers - as an example of what you describe, the 365 RFM doesn't differentiate between a TR control failure and a TR drive failure (loss of thrust) - it is wrapped up into one drill which advises a running landing with a left sideslip on approach and if possible a wind from the right. There is no mention that you will have right sideslip with a drive/thrust failure and no consideration of an EOL for some control/thrust failures at all.

Back to the 92 and the question is how did that vital bearing get to that 'distressed' state without someone noticing something (apart from the crew when they lifted to the hover and convinced themselves the wind was responsible for the undemanded yaw).

FC80

13th Jan 2017, 10:20

Satcomm - I think you're making quite a large jump there. I'd say the footnote on page 4 more or less clarifies the ananlyis tool was available to view, just missed by whoever was inspecting it.

"The IMD-HUMS includes the use of additional stand-alone mechanical diagnostic software tools for the HUMS
Ground Station (GS) that help assess the condition of a number of specific components, one of which is the Tail
Gearbox Bearing Energy Analysis software tool; however, these require the user to visually inspect the data and
search for exceedances. The helicopter manufacturer now offers an alternative GS analysis system which offers
a number of enhancements to IMD-HUMS, including more advanced algorithms and the automatic alerting of all exceedances on receipt of new HUMS data."

LAXX5

13th Jan 2017, 12:13

11 bearings have been removed however none showing any distress like incident bearing.

mtoroshanga

13th Jan 2017, 12:58

Couldnt agree more SASLESS Back in the day Bristow were developing an IHUMS system whereby the aircraft perameters were monitored at all time by an engineer on the ground who could notify the aircraft comander of any impending excedences or failures and discuss options with him. This seems to have disappeared with the Airlog takeover.

SASless

13th Jan 2017, 13:18

Lone,

"we trouble shot the malfunction we thought we had"

The follow up questions I have re your description of the incident and background of that particular aircraft type/model/configuration:

If there are multiple systems that can trigger the symptoms that are presented to the crew.....is there a method to work down through some sort of Trouble Shooting Tree to correctly identify the culprit causing the problem?

Your narrative makes me question the crew action to determine the fault as it would seem (without access to the Accident Report with its information) they may have decided to delay that analysis until they had hovered over to the Maintenance Area and give the aircraft to the Maintainers or have their assistance available in checking out the problem. There are several logical and relatively minor causes for some binding in flight controls that are not threats to the safety of the aircraft and crew.

Would you happen to have a way of calling up that Accident Report as it would make for interesting reading.

I am not finding fault with the Crew by any means....just trying to see how all the Cheese Holes lined up that day.

skadi

13th Jan 2017, 13:28

just trying to see how all the Cheese Holes lined up that day.

Not all cheese holes, at least one was not ...

skadi

Lonewolf_50

13th Jan 2017, 14:02

If there are multiple systems that can trigger the symptoms that are presented to the crew.....is there a method to work down through some sort of Trouble Shooting Tree to correctly identify the culprit causing the problem? {snip the rest}
@SAS The points you raise (good ones) were the topics of a hell of a lot of discussion in our Wing. What was found out was that the NATOPS manual / training wasn't crystal clear on some important details. (The final tech fix to prevent the mechanical failure ended up being some bolts in the azimuth and new preflight check procedures). The NATOPS manual changed, and the control system malfunction procedures were revised to address the distinct differences in symptoms: control position errors versus other system errors. The former became "shut it down" in nature once that accident was thoroughly understood.

NATOPS was written/rewritten in blood ... again .. thanks to a one of a kind failure. Sorry that we are drifting form the S-92 topic, but flight control degradation malfunctions and emergencies are the ones that give me the chills. The initial report from the AIIB gets the hair up on the back of my neck.

Satcomm

13th Jan 2017, 19:58

FC80 - Don't believe it's that big of a jump. You are right and as I stated the toolbar for the TRPCS is there and has been for a long time. All I believe is that it is possible that the engineers at the time, may not have had the same blinding evidence that something is about to happen as Sikorskys team of engineers had in hine sight with their more advanced software. Rumor has it, a new, more advanced Toolbar is hitting the streets. Imagine that!

Mitcha - Dont know what to say. For an operator to put in additional procedures and safety precautions in the wake of a catastrophic event is to be expected IMO, not incriminating. I'm willing to bet every single operator of a S92 has reviewed their HUMS procedures and possibly made changes in the last few days.

The Sultan

13th Jan 2017, 20:49

The post mortum of most, if not all, detectable drive system faults that led to an accident were "missed" not by operator error, but by:

1. System diagnostic programming errors which showed false/erroneous readings which could not detect any faults.

2. Incorrect limits which were set too high and missed the event.

3. (Related to 2) Trying to use sensors located in non-optimum locations to monitor the target component. In the case of the 92, how close is the accel used to the faulty bearing?

4. Routine false alarms which destroys trust in the system, so if something real happens it is lost in the noise (G-REDL). I attended a CAA meeting where operators reported a 100 to 1 false alarm rate with North Sea HUMS.

HUMS is pretty good at detecting the second occurence of what causes an accident after fixing the system short comings highlighted in the accident review. In case of the 92 it appears it requires 3 or more examples.

The Sultan

The Sultan

13th Jan 2017, 23:05

Mitch

I well know HUMS detects faults. I was specifically talking about accidents (North Sea) where people point fingers at operators while believing HUMS is infallible. In accidents where the fault theoretically should have been detected, but wasn't. The majority are due to HUMS shortcomings, not operator negligence.

The Sultan

jimf671

14th Jan 2017, 00:57

Nye helikopterproblemer i Nordsjøen - Nordsjøen - Børs og Finans - E24 (http://e24.no/boers-og-finans/nordsjoeen/nye-helikopterproblemer-i-nordsjoeen/23897501)

Bing Translator
"No one has come to or from the platform since Monday because the helicopter blocks landing place, the BA.

The Sikorsky helicopter from CHC Helikopter Service has been fixed at Kvitebjørn due to an oil leak in gear box. The error should be rectified, but the tests that should be done, have not been implemented because of the bad weather.

-It is of course reassuring that helicopter the company takes all precautions and make the necessary testing, but it is also regrettable for the crew that has been given an involuntary stay on installation, says Morten Eek in Statoil to the newspaper Friday.

On Tuesday reported the CHC that all Norwegian helicopters of the type Sikorsky S-92 carrying oil workers to the platforms in the North Sea, is set on the ground. The reason is that a helicopter of this type spun around and cut a hole in the deck during a landing on the platform West Franklin on the Scottish continental shelf before new year. Now, all the helicopters inspected before the next flight.

The helicopter that crashed last year at Turøy outside Bergen, also belonged to CHC"

maxwelg2

14th Jan 2017, 10:50

11 bearings have been removed however none showing any distress like incident bearing.

According to Oil & Gas People 4 TRPCS bearings have failed inspection and have been returned to the manufacturer for evaluation. 3 were from Babcock S92s, 1 more from CHC.

Non-Driver

14th Jan 2017, 15:38

Non-Driver - for the sake of argument, what you're suggesting re. downloading via WiFi/4G every time the aircraft touches down at home base wouldn't offer any improvement on the current frequency of HUMS checking - I believe every operator in the NS now dowloads the data before every flight - including rotors running turnarounds. :)
By Homebase I meant the HUMS analysis team / equipment (usually at the operator's home base) not that the data only gets sent when the aircraft is at that location. Its sent after every sector ie landing.

212man

14th Jan 2017, 15:55

FAA EAD out now, some differences to ASB: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/a8ca3cce933e47bc862580a7007958f5/$FILE/2017-02-51_Emergency.pdf

jimf671

14th Jan 2017, 17:57

This is far too long a story. :(

2007

http://www.pprune.org/rotorheads/163206-sikorsky-s-92-design-operations-44.html#post3422865

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/df66e46d676b6d258625733e0051eb6d/$FILE/2007-17-05.pdf

PH Pommy 1964

14th Jan 2017, 18:19

Hi All, I have only just signed up to this elite group of birdmen. Can anyone tell me if Wayne Sibley is still around? We trained together at Jayrow Helicopters, Moorabbin in 1969, converting from f/w to r/w. He went to South Australian Helicopters in SA and then to UK with Bristow. I went to Woomera SA for 6 years then back to airline flying for 20 odd years in the UK. Would love to make contact with him.

Satcomm

14th Jan 2017, 20:53

According to Oil & Gas People 4 TRPCS bearings have failed inspection and have been returned to the manufacturer for evaluation. 3 were from

At least 11(may be more by now) have been removed. 7 were picked up by HUMS and 4 by the visual inspections.

HeliComparator

16th Jan 2017, 09:53

Quite a good letter from John Thorogood in the P&J this morning. He makes a very valid point about the seemingly amazing failure to use HUMS properly - again!

I wonder what is behind it. Without knowing any detail my suspicion is the usual one of the "old guard" in engineering, who fully understood how to be good engineers and the importance of HUMS, booted out / retired / retired early due to getting burnt out, and replaced with cheaper inexperienced newbies who don't have quite the same ethos or ability to stand up to ignorant management. Speculation, I'll admit. But...

jimf671

16th Jan 2017, 11:59

Dr Thorogood is a highly qualified and experienced drilling guy who has spent decades in senior engineering positions with a household-name oil company in various corners of the world. (Probably flown in more types than most folk on here.)

His analysis is suggesting that the safety approach that prevents a UK or Norwegian offshore worker cutting their finger or tripping over a cable has not yet reached the aviation industry that flies them out there.

I can see where he's coming from.

HeliComparator

16th Jan 2017, 16:07

Seems there is now a 10 hour repetitive inspection of the tr bearings.

The Sultan

16th Jan 2017, 16:22

[QUOTE]11 bearings have been removed however none showing any distress like incident bearing.[QUOTE]

This alone proves the HUMS as implemented can not be relied on to reliably catch this fault for whatever reason and necessitates changes which hopefully are coming. With HUMS I worked on with optimal sensor locations, working diagnostics, and unambiguous quick glance maintainer alert it was common to detect the earliest indication of bearing degradation. This detection was well before (weeks/months) before a safety issue might occur. While still serviceable bearings might have been pulled, all pulled bearings showed early signs of degradation. Also no bearings that would have been considered acceptable for reinstalling were removed for false alarms.

The fact that so many distressed bearings had been found only after the fact calls into question not only the aforementioned maintainer alerts, but also whether or not the current sensor used is adequate for the task.

The Sultan

Variable Load

16th Jan 2017, 16:35

Or perhaps it demonstrates that the various maintenance departments are being very cautious. An approach that I would applaud.

Only Sikorsky can determine if these bearings are indeed serviceable and also look at the HUMS traces prior to removal. This would be the only way to determine if the current HUMS tool is fit for purpose.

Sultan - you are jumping to conclusions IMHO. However given your previous posts and the obvious bias you constantly demonstrate, perhaps I am wasting my time even responding to your latest offering?

jimf671

16th Jan 2017, 16:36

Seems there is now a 10 hour repetitive inspection of the tr bearings.

That's where the recent FAA AD seems to differ from the previous documents stretching back to 2007.

Would it be reasonable to expect a design change of some sort shortly, whether it's bearing or HUMS or both?

albatross

16th Jan 2017, 16:42

jimf671

16th Jan 2017, 16:57

The FAA AD #: 2007-17-05 shows that this is not entirely new.

Whatever history there is still needs careful attention. I am reminded of a story that circulated in defence quality assurance circles in the 1980s. Whether it is true or folk-legend BS I do not know. A new aircraft type suffered bearing failures. One of the factors that may have seemed completely irrelevant at first was that the government, MoD, makers and the press had all been making a fuss about how wonderful this aircraft was. It turned out that the guy with the grease gun had been listening to this and because it was such a great aircraft and he was really excited to be working on it, it got an extra squirt of grease just to make sure. Oops.

SASless

16th Jan 2017, 17:05

Without knowing any detail my suspicion is the usual one of the "old guard" in engineering, who fully understood how to be good engineers and the importance of HUMS, booted out / retired / retired early due to getting burnt out, and replaced with cheaper inexperienced newbies who don't have quite the same ethos or ability to stand up to ignorant management. Speculation, I'll admit. But...

Probably not so far off base as One might think.

Washing out experience is a pitfall of modern management practices sometimes.

For sure what does happen is a "loss of corporate history" when long serving skilled and experienced Staff leave and the new are presented with a great opportunity to repeat history they know nothing about.

The Sultan

16th Jan 2017, 17:15

Only Sikorsky can determine if these bearings are indeed serviceable and also look at the HUMS traces prior to removal. This would be the only way to determine if the current HUMS tool is fit for purpose.Variable

Variable,

If this is the case then the system is useless until it has an automatic at download alerting capability. Having to rely on Sikorsky for go/no go decisions after every flight is impractical when fault detection is so poor their is only a couple of hours between detection and failure as demonstrated by the current HUMS implementation in the CHC incident.

The Sultan

Satcomm

16th Jan 2017, 20:13

Sultan - Depending on the HUMS ground station being used, operators have several different options as to how they would like to handle their aircraft. Ultimately I'm sure most operators will be moving forward with the SGBA software and latest release of the TRPCS tool. This software and tool allows the operator to reset the 6 hour HUMS TRPCS review themselves rather then waiting on Sikorsky's approval.

lowfat

17th Jan 2017, 13:51

The new Hums Bearing toolbar is Much improved and also more sensitive than previously set.
The fact that Sikorsky has produced this in days rather than months is to be applauded.
As to a cause some suspicion has been aired on the previous practice of inhibiting tail gearboxes by filing to the top with gear oil suspiciously recently withdrawn.
I wonder if the suspect shafts belong to reactivated helicopters?

Pablo332

17th Jan 2017, 14:04

LAXX5

17th Jan 2017, 15:24

Was the oil operating/service oil?
According to Pitch Change shaft and Tail Gear Box records for the incident aircraft, the PCS/TGB had not been in storage and under gone the preservation procedure directing the TGB be filled to the top.

Sevarg

17th Jan 2017, 16:02

Reading this thread it would seem that only CHC and Babcock have rejected bearings. Is this correct? If so what are they doing or not doing that the other UK operator is?

lowfat

17th Jan 2017, 20:22

the preservation oil was normal tgb oil.

Satcomm

18th Jan 2017, 01:11

CHC and Babcock seem to be the only ones that have rejected bearings due to visual inspection. Sikorsky have found issues using HUMS with other operators as well. From what I understand, not all these bearings are being removed for over limit exceedances either. Some have been removed for unexplained trends/spikes/rates that they would like to study and learn from. Obviously everyone are on pins and needles.

The Sultan

18th Jan 2017, 01:41

Sikorsky have found issues using HUMS with other operators as well. From what I understand, not all these bearings are being removed for over limit exceedances either. Some have been removed for unexplained trends/spikes/rates that they would like to study and learn from..

Satcom

With the expense to do the inspection and the $4M+ per seat liability, if a reinstalled bearing fails, no rationale person would ever reuse even a slightly degraded bearing or one that is spitting out "false" fault indications. Replacement bearings are relatively dirt cheap.

Again if you have to dig to see an issue or rely on someone in the ether to make a maintenance call it is not the operator/maintainer at fault. It is a half-ass HUMS which does not meet OGP expectations.

The Sultan

Satcomm

18th Jan 2017, 13:08

Sultan - I agree. However, there really is no digging for the information. The true fact is, the original IMD software does not have the detection capabilities of the new SGBA software. Noe does the original SGBA software, which I believe was used in the initial "detailed analysis" have the same detection capabilities as the latest (Jan 10) SGBA software release.

"To my knowledge" the new software has 2 additional condition indicators added to the tool. Believe these are looking a little deeper into the bearing then just a vibration level (rollers to race freq comparisons/rollers to shaft comparisons). The new software requires less intial data points to set the mean data and the thresholds for collecting these points have been lowered to allow this to happen much quicker. Also, additional algorithms for comparing the the latest data point collected to the previous 20 (looking for step changes rather then limit exceedances). On top of all that, Sikorsky has returned the limit to the original 1.75 from 2.5.

Non-Driver

18th Jan 2017, 13:40

Just an aside.
I have always wondered why, in some instances, a part that has worked well for years, suddenly does not.
Change in supplier, overhaul process ect?
I recall, for example, in the late 70s we suddenly had problems with Allison 250 engines. What had changed?
Usually a process or supplier change upstream in the supply chain. If it is believed by the OEM to be manufacturing to the same specification then no re-proving is required as would be the case in initial certification (if they are even required to be told). It can be driven by raw material availability, cost or process "improvement" (ie efficiency of production). I've even seen Human Factors where the old boy doing inspection retires and is replaced by a new pup. A lot of piece part supply in aerospace supply chains that ends up on Tier 1 product is supplied by surprisingly Mom'n'Pop outfits. You would hope that critical path items would be subject to extra scrutiny no matter how low-tech but that isn't always the case.

Pablo332

18th Jan 2017, 15:47

What’s the story on hums with the S92 do you get full support as standard, or is it like the EC225 pay through the nose for off the shelf hardware and pay through the nose for prompt backup to problems? Basically a tax/revenue stream on safety. Not acceptable in this day and age.

Satcomm

19th Jan 2017, 00:13

Pablo332 - Cant say for sure what kind of cost comes from the technical support side of HUMS but I can say that I have personally never heard any grumbling or negative commentary in regards to the cost so I'm guessing it isn't bad. Having said that, compared to the euroHUMS/IHUMS (332 days, not 225, no experience with 225 HUMS) it does seem to behave much better from an operational stand point. Overall install seems to be much more reliable.

As for user hardware, it's really just the ground station ... Go to the local computer shop and buy a laptop with a PCMIA slot or card reader and off you go. Few hundred quid should do it.

Pablo332

19th Jan 2017, 14:25

Pablo332

19th Jan 2017, 14:52

The IMD software picked up on this with a 5hr warning.

SGBA picked up the same.

Sikorsky then run it though an enhanced algorithm and found that the 5hr pre warning above could actually be detected around 20hrs before with a tweaked algorithm.

This is the basis of the new SGBA patch and the reason why there is a 3hr limitation on flights that continue to use the IMD.

There will be a delay, engineering will need retrained on SGBA so it won't be an instant switch over for the companies that are not using it.

All operators should have their dedicated HUMS specialists, if they can't solve an issue they then go back to the Sikorsky HUMS team.

From my understanding, engineering do not like S92 HUMS as it's based on a bundled up health indicator rather than single condition indicators. The S92 HUMS system very rarely generates alerts, where the other HUMS systems may give out too many. Are the others too sensitive, and is the S92 system too dumbed down? That's the way it feels. Sikorsky only add additional toolbar algorithms post mechanical failures/issues and are not catching things before they break (for the first time)

With conventional condition indicators, SO1/SO2 etc you could work out what was wrong with a driveshaft for example, imbalanced, misaligned etc, the S92 HUMS system doesn't really react like that, it bundles all condition indicators together to create a health score and that's perhaps the reason why it may miss quite a few things.

What I find staggering is this is being going on 10yrs and Sikorsky have not redesigned the component. With EASA/CAA and now UK operators all affected, I would hope that this will be heavily scrutinised.

Sikorsky are only one more incident away from a European grounding on these if this same failure mode happens again and then Sikorsky will be in a whole heap of 'Airbus type' problems.
What I find staggering is that one of the recommendations from the BV234 accident (how long ago), that inflight warnings of imminent failure should be looked into was only implemented by AH ( or anyone)when they had their bevel shaft problems. Once the shaft was fixed out came the warning. A lot of time has passed, I think more time and resources should be spent on HUMS it should be a more mature system than it now is. If you are pushing margins in performance you should also invest in the safety infrastructure that can allow this to happen in a safe manner. Performance is what sells helicopters. Safety is what keeps the company that sold them around.

RVDT

14th Mar 2017, 13:59

AAIB Report - G-WNSR here. (https://assets.publishing.service.gov.uk/media/587640a9ed915d0aeb00013f/AAIB_S1-2017_G-WNSR.pdf)

In particular -

Initial findings indicate that the failure of this specific bearing was rapid; a period of 4.5 hours had elapsed from the first exceedance of
the relevant bearing condition indicator recorded on the operator’s Health and Usage Monitoring System (HUMS) to the point of failure.

A routine download of the HUMS was performed on the evening of 27 December 2016 and the helicopter was released to service.
A detailed analysis of the data, conducted after the accident, showed that the Tail Gearbox Bearing Energy Analysis limit had been exceeded on 27 December 2016.

Downloaded and released by not analysed until after the fact?

Courtesy of (NSFW) Rig Workers Rant (https://twitter.com/rigworkersrant?lang=en)

Right, so the AAIB Report is out on the West Franklin S92 incident and what do we find?
The tail rotor bearing went out of its service parameters 4.5 hours before it failed ie. during the previous day's flying.
The HUMS data which showed this was downloaded the previous night but had not been analysed before the accident occurred.
What the **** is the point of having HUMS on the chopper if nobody is going to look at the data from it?
What the **** is the point of the operator, CHC, introducing a measure to ensure that the maximum time between HUMS download and analysis is 5 hours?
The chopper will have crashed 30 mins before the deadline expires. Why isn't this data being analysed in realtime? It's not like the technology isn't available!
Frequent flyers will also be interested in learning that 4 S-92s failed their checks. None of the Norwegian choppers failed, odd that!

Sounds like real time analysis is supposed to be the fix if you drink the Kool Aid on offer by SK at HAI.

Meanwhile .......................................:=.............. :rolleyes:

chw

16th Mar 2017, 15:20

How is this tail-rotor installation different from the tail-rotor installation on the black hawk ? ( oil filter installation on the Black hawk has steel bolts s 92 had titanium bolts).
So where did they save weight in the tail rotor installation ?

Apate

16th Mar 2017, 15:42

How is this tail-rotor installation different from the tail-rotor installation on the black hawk ?

Well, seeing as you're the one stating it's different, why don't you tell us?

212man

22nd Mar 2018, 11:46

Final report out: https://assets.publishing.service.gov.uk/media/5aa79fb4ed915d4f563b7291/AAR_1-2018_G-WNSR_Lo_Res.pdf

Just reading it.....

212man

22nd Mar 2018, 13:22

I still struggle with the decision to take off a second time, given it was accepted by the crew that full left pedal had been used and it had not arrested the uncommanded yaw. The S92 has very powerful TR authority so any inability to use it must indicate something other than wind effects.

gulliBell

23rd Mar 2018, 10:50

I still struggle with the decision to take off a second time, given it was accepted by the crew that full left pedal had been used and it had not arrested the uncommanded yaw...

Me too.....

Mee3

23rd Mar 2018, 14:25

So HUMS picked this up the night before but during the analysis the graph was ‘stuck’ and the exceedance wasn’t clear (look at the scaling on the right hand side) and the engineer released the helicopter.

If he had resolved the stuck graph and zoomed in on the data as shown in the additional graph, the exceedances were clear to see and the TGB bearing would have been inspected that night.

So the event was totally avoidable and was just sheer luck that the failure happened 6ft above a helideck. Anywhere else and that would have been in the water or in a field.

I can see why it happened, but Jesus, it was clear as day, it should never have left Aberdeen that day. I can imagine the engineer having a hard time trying to explain how he missed that. The importance of Human Factors training I suppose.
Do you even know how HUMS works? talking a hind sight is easy thou'

gulliBell

24th Mar 2018, 02:38

..No hindsight about it, it was a human error, he shouldn’t have signed for something that he hadn’t done correctly.

Sure, as pilots we need to rely on other people to do their job properly. Despite this, ultimately the pilot is responsible for the final disposition of the aircraft. If I was flying an aircraft that did an unexpected 45 degree right turn in the hover that was not arrested with full left pedal I would most certainly be parking the bus on that very spot and calling one of those aforementioned other people to deal with it.

JulieAndrews

24th Mar 2018, 12:34

No armchair required here.
Is there an increasing number of incidents/accidents that show a decreasing level of Captaincy in O&G?
You can have 1000s of hours going from A-to-B under strict regulations, Met-monitoring, sea state monitoring, rig cloud base reporting, sms devouring conditions - and still not build ‘Captaincy’.
Just like the EC155 SNS incident where the ‘captain’ continued despite glaringly obvious indications (and various other cases of ‘push-on-it’s’) the Captain should have parked the aircraft when it turned 90 without his demand.
Where was the ‘Co-pilot’ CRM?
I suggest if you can’t control an aircraft on lift within 10 degrees on ‘lift’ - regardless of deck turbulence, then you shouldn’t be flying. Especially with the tr auth of a 92.
Wtf was the ‘co’ doing?
This is from a company that harps on about CRM and glossy safety seminars??
Crews need to grow some preverbials.
Captaincy is dead, long live Captaincy!
HUMs action and engineer competency/diligence are ‘barriers’ - the accident happened because the crew did not behave like a crew and a lack of good old fashioned CAPTAINCY.

cyclic

24th Mar 2018, 14:23

Problem is, crews are no longer allowed to demonstrate airmanship. Everything on the North Sea is done by a manual which is great until you come across something that is not in the manual. If it is not in the manual then the immediate reaction is to ask a manager. Our ability to dynamically risk assess has been worn away by procedures and rules written by people who have never done it, done it and were useless or self-appointed experts. Unfortunately, when the unusual event happens, neither the manual nor the manager is of any use. Of course, there is a growing feeling that everything Sikorsky is good and everything Airbus is bad. This leads crews into thinking that the S92 is infallible - it ain’t. This is demonstrated on a near daily basis, there are just a lot of them which masks a lot of problems. To miss a HUMS warning is inexcusable, particularly if this kind of thing has happened before. Statistically, we are due another event and with activities levels about to rise without the experience and support of pre-downturn years, everyone needs to be on the ball.

gulliBell

24th Mar 2018, 14:58

Problem is, if something goes wrong, as a pilot you need to be able to, firstly, keep focussed on flying the aircraft, and then note the symptoms, make sense of the symptoms, arrive at a likely diagnosis and proceed with an initial course of action. All that before you look at any manual. No room in any of that for consultation with anybody who is not sitting immediately to your left or right. You just can't be diluting that fundamental aspect of piloting.

Something is fundamentally wrong in the North Sea. Why do accidents happen in the NS at the rate they do but, by way of comparison, in 50 years of operational O&G flying in Bass Strait Australia - which has its fair share of bad weather and all those other things - not a single accident in all that time. Just saying.

EESDL

24th Mar 2018, 16:22

Maybe they have larger ‘preverbials’ down under?

Is the licensing route to an ATPL similar ?

gulliBell

24th Mar 2018, 23:41

Maybe they have larger ‘preverbials’ down under?

Don't know. The only fundamental difference I can think of is the oil company has always directly owned and operated all the helicopters and physical infrastructure and management structures etc to support them. And for the most part they are pretty much left alone by the regulator to run their own show without too much external oversight.

Hedski

25th Mar 2018, 00:11

The short version is that nowadays oil and gas crews are examined at OPC time mostly, not completely, but mostly by TRE’s with only the knowledge of what it says in the big book and no actual common sense. Examinations are all procedural. So neither the captain or copilot in this case really had that much to go on training wise. Add to this that the company in question have been pushed to promote people by virtue of time served and not actual ability which is all that matters to the unions in U.K. and Ireland, jobs for the boys (and girls), which may not be the case in this instance but overall as a result the ethos for captaincy is then degraded in terms of actual ‘CAPTAINCY’ as Julie is suggesting. Combine this with the question of copilot CRM and I can tell you from personal experience in 2 out of the big 3 North Sea companies that CRM stopped when certain captains decided. It is still the case that those who choose to bully their way in the cockpit exist as much as they did 30 years ago, therefore copilot CRM and the ability to interject suffers.

jimf671

31st Mar 2018, 06:54

... ... Of course, there is a growing feeling that everything Sikorsky is good and everything Airbus is bad. ... ...

You mean the Teflon Aircraft Corporation of Stratford Connecticut.
The numbers do tell us something different.

Fareastdriver

31st Mar 2018, 08:51

Of course, there is a growing feeling that everything Sikorsky is good and everything Airbus is bad.

It's all horses and roundabouts. In the past S61s were swimming around quite regularly, S76s were throwing rotor blades and Chinooks were either swimming or falling apart in the air.

My opinion with over thirty five years of flying Pumas of different types is that they are trying to stuff too much wine into the bottle.

As far as pilot ability is concerned I was once called a dinosaur on this forum because I said that I used to like to fly the odd sector without the autopilot so as to keep in practice.

Jimmy.

13th Apr 2018, 01:29

Aknowledging the lack of Captaincy, maybe this information could be useful to 'today' crews:

"Additionally, the helicopter manufacturer reviewed their archive of flight data records to determine whether it is an unusual event for a pilot to use full pedal travel in flight. The analysis showed that the use of full pedal was very rare but had occurred in each of the previous events of TRPCS bearing failure(see paragraph 1.18.2). Conclusions from the review were that this cue is available to flight crew prior to bearing failure, but is indicative of a bearing that is already in an advanced state of degradation. Thus, the use of full pedal travel could indicate a need for prompt action to abort a flight and the helicopter manufacturer is considering whether changes to the RFM could be introduced." (Accident Report, pg.52)

SASless

13th Apr 2018, 11:28

There is a huge difference between checking and training!

It is not the “union” pressure that saw “snot noses” shoved up the food chain by at least one major North Sea Operator.

A wave of newly blessed kids with scant experience found themselves the standards setters and it did not always end up in Wine and Roses.

chance it

13th Apr 2018, 17:10

So the reason this accident happened is down to the crew and their training ?? How do you train pilots and program simulators for something that’s not supposed to happen ? That bearing could give up in a variety of different ways and of course at any flight phase.

Unless Sikorsky can assimilate all the TRPCS event data and confirm that they all failed in exactly the same way and same time frame I don’t see how you can ‘train’ for this event .There are a million different ways a helicopter can have mechanical failure that leads to loss of Main and/ or Tail rotor control ...e.g MR Servo bolt failure or Scissor bearing failure (See recent Sikorsky Safety advisory).Why don’t Sikorsky actually FIX the TRPCS bearing problem ....? Because they still have no root cause for the failure.

In the meantime we are all ‘happily’ flying around in them because HUMS ‘might’ pick up on it 😂. Ironic that the 225 is canned because of as yet no proof of root cause meanwhile we are happy to accept this issue on the S92 when the manufacture has done nothing to resolve it. Personally I can’t see why this thread has descended in to a ‘Crew fault/Crap training/‘snot nose’ debate , surely we should remember we are all human and that this crew in the end saved everyone on board and potentially another Facebook campaign to ‘keep the N.Sea 92 free’.

SASless

13th Apr 2018, 20:57

How does one learn what is abnormal control responses are, how they are manifested, and recognized and a proper action to take upon encountering such abnormal control responses?

Training, experience, combination of both perhaps?

How do you set a minimum standard for that especially for new Types?

I would suggest the tail rotor control response issue is several orders of magnitude different than that of the 225 shucking the entire main rotor system.

Jimmy.

13th Apr 2018, 20:59

chance it

13th Apr 2018, 22:12

“I would suggest the tail rotor control response issue is several orders of magnitude different than that of the 225 shucking the entire main rotor system.”

And I would suggest that it wasn’t just a ‘tail rotor control response’ issue. It was a mechanical failure of the Tail rotor pitch control shaft bearing.
It’s not just the fact you lose control of the Tail rotor but more importantly the forces involved . Imagine the damage done to the TGB and the vibration to the whole assembly if this had happened in the cruise on the way home . Could these forces have led to eventual break up of the TGB due to heat and vibes if sustained ? Leading to loss of the TGB/TRH and blades ? In my opinion in all the instances of this failure the crews and A/C got lucky as they were all on final approach or close to a landing site . Even titling this as an ‘Unexpected Control response’ was underplaying it in my opinion, and I was shocked this was the title of the news flash distributed to N.Sea operators when it happened. Which ever way you want to view it this is a Nasty accident and for a problem that hasn’t gone away. Hums is only as good as the people deciphering it.
But if people want to continue thinking this aircraft is somehow safer than a 225 then carry on ! I fly it every day and I know it’s just another helicopter...

chance it

13th Apr 2018, 22:25

I think we may be comparing apples and oranges here. The report is clear about the human error on interpreting the HUMS data (available the night before the accident). Now, a HUMS download and analysis is made after each flight. Despite the gravity of a TR control failure, it was detectable (4.75hrs and the full left pedal) and quite different than loosing the MR without warning.

If you’ve read the AAIB reports on G-REDL and the other two bevel gear failures in the 225’s in 2012 you would also note that HUMS actually picked up these failures several hours before too .....apples and oranges ? At least now all the operators are mandated to look at the hums downloads every flight that is one good thing ....but they had to be forced !

Brother

14th Apr 2018, 03:56

If you’ve read the AAIB reports on G-REDL and the other two bevel gear failures in the 225’s in 2012 you would also note that HUMS actually picked up these failures several hours before too

But it didn't pick up LN OJF's catastrophic failure. All TRPCS shafts are now run in before being released. Sikorsky is looking at an improved design. There hasn't been any more failures. I am happy flying the 92, I prefer it to the 225 to operate, its predictable and reliable even if the autopilot is no so whizzy as the 225.

Apate

14th Apr 2018, 06:53

The EC225 bevel gear debacle is not why they are currently not being used (although it didn't help!), it is because LN-OJF suffered a catastrophic failure of the MGB that was not and cannot be detected by HUMS or any maintenance practice. This is compounded by no definitive root cause being identified.

Airbus did themselves no favours during all of the EC225 woes with their public denial and mud slinging, rather than being open and honest or even just saying very little.

With the current S92 issue, we have a HUMS process that has been shown to work. The HUMS did it's job, but the alert was missed (not for the first time by CHC UK). HUMS itself has been subsequently modified to make it more "user friendly".

As mentioned earlier, Sikorsky are now working on a suitable modification.

Chance It - the general negative tone of your messages are worrying. I suspect you are in the wrong job if this is carried into the cockpit every day! Or perhaps you just need to sober up on a Saturday morning and take a deep breath :E:E:E

chance it

14th Apr 2018, 08:47

The EC225 bevel gear debacle is not why they are currently not being used (although it didn't help!), it is because LN-OJF suffered a catastrophic failure of the MGB that was not and cannot be detected by HUMS or any maintenance practice. This is compounded by no definitive root cause being identified.

Airbus did themselves no favours during all of the EC225 woes with their public denial and mud slinging, rather than being open and honest or even just saying very little.

With the current S92 issue, we have a HUMS process that has been shown to work. The HUMS did it's job, but the alert was missed (not for the first time by CHC UK). HUMS itself has been subsequently modified to make it more "user friendly".

As mentioned earlier, Sikorsky are now working on a suitable modification.

“Chance It - the general negative tone of your messages are worrying. I suspect you are in the wrong job if this is carried into the cockpit every day! Or perhaps you just need to sober up on a Saturday morning and take a deep breath” :E:E:E

All of your statement doesn’t detract from what I said ...it was a lot more serious than an ‘unexpected control response’ , and had it happened away from a landing site could have had a very different ending .
Apate , for negativity read realism. It seems ok to berate the Puma on this forum but to even question the S92 one gets accused of being drunk ?

Mee3

14th Apr 2018, 09:04

the argument is moot when the norwegian themselves called the fault on EC before even finding evident and EC duly complied with demonstration that it is very unlikely the few early theories the norwegian thought were the root cause to the event. The continuing no finding only proof that it has nothing to do with the design and build. Only people with agenda is pushing such idea till today.

talking about HUMS, it is not as easy as some people here would like it to be. It is until today still a brilliant idea that never been reliable in actual operation. No matter the system from which OEM attached with which OEM's frame, they are all plague with noise and fault reading. It is very easy for the OEM and top expert in the investigation to point out the "obvious". But to the people on the floor with all kinds of factor in effect, human factor just bound to happen.

Fareastdriver

14th Apr 2018, 09:16

What is missing from HUMS is something that we wanted to have when it first started in the 1980s. A light in the cockpit which would say.

DO NOT FLY THIS HELICOPTER
or
LAND AS SOON AS POSSIBLE

Brother

14th Apr 2018, 10:23

What is missing from HUMS is something that we wanted to have when it first started in the 1980s. A light in the cockpit which would say.

DO NOT FLY THIS HELICOPTER
or
LAND AS SOON AS POSSIBLE

Problem is that if we had that on the 225, there would have been other unnecessary ditchings as the MARMS was often throwing up serious warnings on download which were spurious.

Fareastdriver

14th Apr 2018, 12:11

I said LAND, not DITCH it.

SASless

14th Apr 2018, 12:26

Chance,

Perhaps I wasn’t clear enough earlier.

My point was meant to be...a Pilot had to use full yaw control input in conditions not requiring such extreme input in an aircraft generally accepted as having excellent amounts of tail rotor authority.

I would think a proper reaction to that singularity would have been along the lines of....”Whoa...what the heck just happened!” followed by some discussion with his Crew Mate along the lines of “Did you see that?”.

When your flight controls noticeable differ from normal inputs for any given situation there should be some healthy concern.

What I am describing is analogous to a sudden onset of an unusual vibration while inflight....if you notice the change....you should consider the source and implications resulting from that unusual event.

Jimmy.

15th Apr 2018, 00:05

All of your statement doesn’t detract from what I said ...it was a lot more serious than an ‘unexpected control response’ , and had it happened away from a landing site could have had a very different ending .
Apate , for negativity read realism. It seems ok to berate the Puma on this forum but to even question the S92 one gets accused of being drunk ?

I agree with you. IMHO, it was at least a lost of tail rotor control (if we assume the power increase for landing occured well before the bearing total collapse -because they were already over the helideck at 4ft- and the sharp yaw to the right, we can think on lost of thrust as well, despite the report stating it was not). And yes, it could have been a disaster. And yes, the 92 is subject to failures.
Reading other threads, I also noticed a "225 vs 92" tendency on posts. I fly the S92 and feel safer than if I was flying the 225, what I could do without problem if required to.
Maybe the magnitude of the failure, as said before, and the manufacturer way of dealing with situations like these make people (not just some pilots) think this way.

Brother

15th Apr 2018, 06:34

I said LAND, not DITCH it.

Great, 100nm from the nearest land or offshore site and the light comes on.

The 225 did have a similar light though with the "temporary" gearbox shaft fix in 2012-13 which allowed 30mins flight at Vy.

bigglesbutler

15th Apr 2018, 11:24

Except that a hums warning is generally found at base after landing is it not? I admit I haven't flown a heavy since may 2016 so please disregard if things have moved on since then.

Si

Heliflyger

17th Apr 2018, 06:42

In the early days of the S92, a Norsk Helikopter crew experienced the same failure enroute to Bergen. They treated it the way they were used to trough their simulator training/OPCs and did a perfect running landing accordingly in Bergen.
I believe the focus we have in Norway on using simulators for training and not only checking, is the right way to building experience/confidence among the crews.

Robbo Jock

17th Apr 2018, 20:36

What is missing from HUMS is something that we wanted to have when it first started in the 1980s. A light in the cockpit which would say.

DO NOT FLY THIS HELICOPTER
or
LAND AS SOON AS POSSIBLE

The problem is that there is a huge gulf in certification between software taking measurements in flight that will be downloaded on the ground for analysis by engineers/computers to make an "it would be a good idea to manually check this bit of the aircraft" decision, and software that takes measurements in the air to present an indication to the pilot as to whether to continue flight or not. A huge gulf.

HUMS is predicated on the situation that there is sufficient time between a degradation becoming detectable and the subsequent failure of a component, that download of the data and ground analysis of it will detect the former before the latter. Trying to put general-purpose measurement and analysis functions onto the aircraft such that the result is instantly available to the pilot as a 'land NOW' indication is not only expensive, but it is hard. There are numerous false positives that could, conceivably, cause aircraft (and people) to be lost due to Land Immediately alerts that are wrong.

Given the general assumption within the use-case of HUMS, it is not actually a good vehicle for flight deck alerts - it is an indicator to an engineer that there could be a problem with a particular part of the aircraft and hence that should be checked. It is up to those checks to determine whether the aircraft should fly or not.

If there is a specific failure case where the time between a degradation being measurable and the subsequent failure occurring is too short for the 'standard' HUMS turnaround then there is a very good case for developing and installing systems to measure and alert on that specific situation. These would be developed to the appropriate certification level and the results (hopefully) be trustworthy enough to present on the flight deck.

212man

18th Apr 2018, 08:00

Trying to put general-purpose measurement and analysis functions onto the aircraft such that the result is instantly available to the pilot as a 'land NOW' indication is not only expensive, but it is hard
And essentially is showing that HUMS is not doing the job it's intended to do (as you describe).

SASless

18th Apr 2018, 11:32

EESDL

18th Apr 2018, 12:15

Every ‘aid’ to assist decision making is welcome but -
On one hand we bemoan the increasing automation of flying and the consequential degrading of flying skills - on the other hand we stress the importance of ‘captaincy’.
However we all know that companies only like demonstrations of ‘captaincy’ when it does not affect the schedule or bottoms line.
The crew had ample indications that this flight should have stopped way before they ‘manfully’ kept it on the deck. Unexpected requirement for full opposite pedal FFS!
Hums appears great and is as good as the engineer interpreting the data - by all means make the data less ambiguous but please let us not forget the real failing here and where any resources should be targetted.

212man

18th Apr 2018, 12:38

Is my impression that HUMS is doing its job....but the Human Interface is causing the failures to effectively warn the Pilots that result in tragedies?

It seems the required response to the output of the HUMS systems has been lacking in several of the events.

It takes effective, timely, and accurate interpretation of the Data to complete the Loop on HUMS and what is expected of it.

I didn't mean in general - I meant that if you had a warning in the cockpit that said 'land immediately' it would imply the HUMS wasn't doing its true role prior to that.

FH1100 Pilot

18th Apr 2018, 14:17

Like many who post here, I have considerable offshore time. Granted, it's only Gulf of Mexico time and only in relatively small ships compared to the S-92, but i'd be surprised if the wind limits overseas are much different than what we adhered to in the GOM.

That said, I can't recall a single time in 13 years of offshore flying when it was required that i put in FULL left pedal response to a gust of wind while in a hover. Such a gust would undoubtedly produce a rolling or sliding effect in addition to the yaw. Wind over offshore platforms is seldom uniform in any respect. It's quite chaotic, especially when the velocity increases to the point that it would cause yaw excursions in a (big!) hovering helicopter much less the puny 206's and Bo-105's I flew.

Now we get to an S-92 pilot who had to push FULL left pedal to counter an uncommanded yaw. And then he took off anyway without further questioning or troubleshooting? Look, there may not have been a light on the dash that said, "Do Not Fly This Aircraft," but there sure should have been one in the minds of that crew! I mean, aren't we supposed to be the "brooding introspective anticipators of trouble" that newsman Harry Reasoner observed about us back during the days of the Vietnam War?

When did we stop that?

I think it's totally right and justified to look into the captaincy issues at play here.

SASless

18th Apr 2018, 21:04

Years ago in the dark ages we had In-Cockpit Blade Integrity Indicators in addition to Individual blade mounted indicators. Overtime...the Cockpit Warning Lights were removed due to spurious indications and the Blade Indicators remained.

Different technologies separated by quantum leaps in sophistication.....but similar issues in how to include the Pilot into the equation!

HeliComparator

19th Apr 2018, 00:03

On the captaincy issue, I think a chunk of the problem is that the offshore industry is so brow-beaten by cuts and clients breathing down necks wanting to make a big fuss about any glitch in the service, that there is a tendency to just want to keep one’s head down and not make a fuss. Turned into bus-driving zombies if you like. One can argue that pilots shouldn’t react like that, but human nature is what it is and no point in trying to pretend otherwise.

finalchecksplease

19th Apr 2018, 06:23

Brother

19th Apr 2018, 10:25

On the captaincy issue, I think a chunk of the problem is that the offshore industry is so brow-beaten by cuts and clients breathing down necks wanting to make a big fuss about any glitch in the service, that there is a tendency to just want to keep one’s head down and not make a fuss.

well that's not the case on the contract I fly. If we stop for any potential safety related problem we get nothing but support and even praise from the clients health and safety and aviation departments

212man

19th Apr 2018, 10:53

industry insider

19th Apr 2018, 14:57

Agree 212, we stress it constantly.

EESDL

19th Apr 2018, 16:47

Agree 212, we stress it constantly.

You are fortunate - as many companies stress ‘safety’ but when it comes to perceived cost savings they appear to be simple words.
Heck, one such company even has the temerity to host an annual Safety Conference, inviting the ‘Great’ and the ‘Good’! The same company in fact which threw aircraft at customers at a loss then entered Chapter 11.
Not all companies are the same of course and you guys must be some of the lucky ones but you are in a minority.
It is increasingly difficult for Accountants to regard the crew as invaluable, highly-regarded assets when so many of them behave as blinkered bus drivers, fearful for their own longevity. T&Cs are a joke for such a responsible position. The classic downward spiral of “getting what you pay for” has been costed by the bean counters and affect to financial and reputation assessed as “acceptable”.
That said, it is amazing how just one strong and knowledgeable manager in the right position can effect change for the good so keep your chin up ;-)

HeliComparator

19th Apr 2018, 22:08

well that's not the case on the contract I fly. If we stop for any potential safety related problem we get nothing but support and even praise from the clients health and safety and aviation departments

Do the client’s health and safety and aviation departments pay the bill and sign up the contractor again at end of contract? Large oil companies are not homogeneous, there are different internal factions at play and sometimes the contractor is the piggy in the middle.