Robinson down in France

[alicopter]

Sad news from France... 2 dead in Robinson, father and son, (apparently disintegrating mid-air) over Valouse (Drome, South of France), flying from Clermont Ferrand (Puy de Dome) to Le Luc (Var). RIP guys and condoleances to family.

Crash d'un hélicoptère dans la Drôme : découverte d'un deuxième corps - France - TF1 News (http://lci.tf1.fr/france/faits-divers/crash-d-un-helicoptere-dans-la-drome-decouverte-d-un-deuxieme-7498252.html)

[206Fan]

A helicopter disintegrated in flight on Monday at 10:30, while flying over the Drôme. According to information from France Télévision (http://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=fr&tl=en&twu=1&u=http://www.francetvinfo.fr/drome-un-helicopetre-se-desintegre-2-corps-dans-les-decombres_136106.html&usg=ALkJrhjSPYASXwwVT3jrsLothsFuElcEMw) , rescuers have so far found two bodies at the scene of the crash, which occurred in the town of Valouse. For its part, the prefecture evokes one death for the moment. The unit could accommodate four people, according to the website of FTVI (http://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=fr&tl=en&twu=1&u=http://www.francetvinfo.fr/drome-un-helicopetre-se-desintegre-2-corps-dans-les-decombres_136106.html&usg=ALkJrhjSPYASXwwVT3jrsLothsFuElcEMw) . The private helicopter registered in Spain came from Switzerland and headed for the Iberian Peninsula, according FTVI. A witness contacted by France 3 Rhône-Alpes (http://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=fr&tl=en&twu=1&u=http://rhone-alpes.france3.fr/info/crash-d-un-helicoptere-dans-le-sud-de-la-drome-75334604.html&usg=ALkJrhjPX6OMYJz8XghEZ3ttOZiaSEn08A) , said: "It was a normal helicopter noise and then the sound became increasingly hoarse, which made ​​me look at what was happening. And then it stabilized and fell sharply. There was no explosion, it broke up. I think it is a mechanical problem because the blades have stopped. "
ASN Aircraft accident 03-SEP-2012 Robinson R-44 (http://aviation-safety.net/wikibase/wiki.php?id=148481)

[hillberg]

Pylon whirl,:eek: Low gross wt & high speed flight.:} Get a little chugging :=,Slow down.:rolleyes:

[Soave_Pilot]

There we go again...

[MartinCh]

hillberg, if you 'slowed down' as recovery from mast rocking, what'd be your collective input, just BTW? Since the FAA letter regarding the phenomena, most of it covered here. (http://rotorpad.com/general/ntsb-issues-5-recs-to-faa-re-mast-rocking-vibration-in-the-main-rotor-assembly-of-robinson-helicopter-r44-helicopters.html) and R44 Mast rocking aka 'Chugging' (http://www.pprune.org/rotorheads/461705-r44-mast-rocking-aka-chugging.html)

Nothing indicates it couldn't have been low G/mast bumping.
The 'hoarse noise' could be just blade slap noise.
Very sad news indeed. I fly Robinsons and wish there weren't such issues with the design, as all of us, I guess.

EDIT: The 'hoarse noise' could correspond with sudden spar/skin debonding.

[Arrrj]

Terrible news.

I am not sure where mast chugging etc theories come from when this statement was made "I think it is a mechanical problem because the blades have stopped. "

It sounds to me like the motor ceased to operate.

Whatever, it is a reminder to take care flying helicopters of any sort, and be ready for the unexpected.

Arrrj

[hillberg]

It's a problem that surfaced when the mount rubber was changed (vender or other factor) :rolleyes:chugging could become excessive to the point of pylon whirl, not a good thing, := this makes another in flight break up.:{

[roondog]

Maybe the tail fell off. That has has been known to happen in Robinson products.

[206Fan]

Roondog,

Backing up your statement might help. Some of us have to fly Robinsons.

[RPM AWARE]

I think he's alluding to the R66 rumour mill....

[blakmax]

This sounds very much like the break up of R44 DQ IHE in 2006 in Fiji. Sudden change in sound, break up in flight. I was involved in that investigation and find it totally unbelievable that CAAFI have not released that report. They have had the report for several years now. Even if it turns out that the report bears no relevance to this incident, the investigators really should use the guidance provided in the report to eliminate the probable cause identified by that investigation. The most probable cause identified in the report has not been reported elsewhere and does have safety of flight implications. I would think that CAAFI have a duty of care to release the report, even if they disagree with the findings.

Regards

Blakmax

[roondog]

The break up I am referring to, is the brand new 44 that was leaving the factory, headed to Canada, that lost it's tail in flight. I haven't seen the final report on this, so I can't comment as to the cause and whether the issue has been addressed and/or resolved.

[Arrrj]

Blakmax,

Would you be so kind as to tell us all what your theory is on the Fiji accident. You have been commenting on this for a while. Why don't you share your knowledge.

Arrrj

PS - nothing falls off a helicopter, Robbie or otherwise.

[RPM AWARE]

"PS - nothing falls off a helicopter, Robbie or otherwise"

sorry, but that's incorrect

[onetrack]

nothing falls off a helicopter, Robbie or otherwise.

Arrrj - You might want to re-phrase the wording of your post, while there's still time!

Door falls off Helicopter at the Galway Airshow - YouTube

[blakmax]

I have had several PMs and direct questions about my theory with R44 crashes and I have been waiting for the report to be released. For all of those who use the mantra "Wait for the report" what do you do if the report is not released? I am not totally aware of the legal implications of releasing information before the report is released, but given the time which has elapsed, I see no alternative. However, I shall couch my comments in the terms I gave to the IIC and the comments already released by the NTSB. I will NOT preempt the IIC's conclusions.

Firstly Aaarj, bits DO fall of helicopters if there is a structural failure. This was the case here.

I do need to do a bit of posterial tin plate protection so I here quote the NTSB assessment at A08_25_29_Recommendation in relation to DQ-IHE.

The fracture faces in the remaining portions of the adhesive bond joints showed mixed cohesive and adhesive failure fracture features with a large percentage of adhesive failure, indicating that the bond strength deteriorated after the blade was manufactured.

Further The Safety Board has determined that the adhesive fractures in the main rotor blade from the Fiji accident helicopter propagated from the blade tip and leading edges and cannot rule out the possibility that the in-flight breakup was initiated by a bond failure at the tip of the blade.

Adhesive failure fracture features result from a dissociation of the chemical bonds at the interface due usually to hydration of the oxide layers on metallic adherends. All epoxy (any polar molecule) will absorb atmospheric moisture and that provides the water necessary for hydration. Hydration resistance is controlled by surface preparation at the time of manufacture. In every case, adhesive (more correctly adhesion) failures result in very weak bonds and in the extreme can result in negligible bond strength. They are time dependent, with strength decaying exponentially from the time of manufacture.

I then refer you to my paper: http://www.adhesionassociates.com/papers/56%20Assessing%20Adhesive%20Bond%20Failures%20-%20Mixed-Mode%20Bond%20Failures%20Explained.pdf

Note that some of the pictures are of a specific failed R44 blade.

This paper explains the significance of mixed-mode failures. These result when the interface has commenced degradation, but at some time a sufficiently high load is applied which results in joint failure. If such joints had not experienced that higher load, then they would maintain apparent integrity. The longer they are in service, the lower the failure load needs to be. Mixed-mode failures are in fact clear evidence that the bond strength has degraded below that at the time of manufacture.

Now, currently blade integrity is managed by an AD which requires frequent inspection. What did the NTSB say about tap testing? The Safety Board is concerned that tap testing is not adequate for detecting bond defects in critical bond joints of the main rotor blade, such as areas between the skin and spar at the tip of the blade and between the skin and tip cap. The intact main rotor blade from the Fiji helicopter was tap tested on site and at the Safety Board’s Materials Laboratory. Neither tap test detected the 0.5-inch debond area that was visually detected at the tip of the intact Fiji blade.

The Safety Board believes that the actions required by AD 2007-26-12 may result in the detection of some defects but will not detect hidden bond flaws at the spar-to-skin bond joint and the skin-to-tip cap bond joint. The investigator-in-charge of the Fiji accident reported that the main rotor blade from the helicopter involved in the event in Australia was tap tested prior to flight, but a bond defect at the skin-to-spar bond joint was not detected. This failure, as well as the Safety Board’s tap testing of the intact Fiji blade, which did not detect the debonding, demonstrates that tap testing does not detect bond flaws in the main rotor blade consistently.

Even if the tap test was an effective method for disbond detection, is that an adequate measure to assure structural integrity? I again refer you to a recent paper:
http://www.adhesionassociates.com/papers/57%20Safety%20Risks%20in%20Applying%20Damage%20Tolerance%20A nalysis%20to%20Certification%20of%20Adhesively%20Bonded%20St ructures%20and%20Joints.doc

This paper clearly shows that for joints susceptible to mixed-mode and adhesion failures, the usual methods for establishing tolerable defect sizes are inappropriate. Often, the size of tolerable defects is established by testing joints with teflon inserts to simulate defects, so if the structure survives loading with that size defect, all such defects should be safe. That assumption is simply not true for mixed-mode and adhesion susceptible surfaces. It is also not true for micro-voiding (porosity). Why? Because the test conditions result in adhesive bonds surrounding the defect which are not degraded. In practical disbonds which occur due to adhesion, mixed-mode degradation or porosity, there is no way of ascertaining that the surrounding adhesive has not been degraded. In fact it often is very degraded. It may still maintain sufficient contact to pass NDI, yet the interface or the adhesive is so degraded that the bond strength is well below that required to provide sufficient bond strength.

The AD also made reference to erosion of the leading edge paint leading to the exposure of the adhesive bond and suggests that this leads to the failure. I have seen evidence of such erosion, but I assert that if this was the cause of failure, the failure in a joint with an appropriate level of strength, there would be cohesion failure (fracture through the adhesive at high bond strength). The evidence is that there have been a number of cases of at best mixed-mode failure. It is my contention that the only role erosion could possibly play is if the bond interface was already degraded, then erosion may possibly (?) contribute to an earlier failure than would have occurred in the absence of erosion. In other words, failure would occur without erosion. So paint integrity or the use of leading edge tapes would not prevent bond degradation.

In summary, the NTSB agreed that there was evidence of adhesion and mixed mode failures in DQ-IHE blades. My papers explain the significance of mixed-mode failures and adhesion failures with regard to strength. The papers also explain that even if effective NDI methods existed, they are inappropriate for surfaces susceptible to adhesion or mixed-mode failure, and porosity.

It is my opinion that the only way to assure flight safety is to withdraw a number of blades from service and test them to destruction. The NTSB report noted failures in low-life blades The blade with the earliest debonding had accumulated only 331.2 hours TIS. Start there and follow through to the designated service life.

I would also add that TIS is not the correct parameter. Time since manufacture (TSM) may also be just as important. The ATSB reported on one blade which exhibited disbonding at the root fitting after ZERO flight hours.

I feel I have a duty of care to make my observations public, even if CAAFI and others do not wish to do so. Even if the French accident is unrelated to this cause, something must be done to address the integrity of blades. And for those Robbie floggers, there is also evidence of problems on other types. The root cause is that the current regulations do not require demonstration of bond durability. They only require demonstration of static strength and fatigue resistance. The requirements for adequate bond durability are buried in advisory circulars and policy documents, and are often not understood by certifiers. But even if that changed tomorrow, it would not change the fact that there is a risk of lives being lost because of inadequate bonded structures in current service.

Regards

Blakmax

[Arrrj]

Blackmax,

Excellent report and thank you for posting it.

Given that you appear to be an expert in the field, what is your view of the new blades fitted by Robinson (series 7 I think ?).

Arrrj

PS - I'll make sure my doors are closed before take off...

[blakmax]

Aaaarj

I am unaware of the methods used to make the new blades, so I have no way of assessing their potential performance.

I don't think this had anything to do with doors.

Regards

Blakmax

[Heli-Jock]

Jeso, not another one!
At the expense of upsetting the "wait till the report comes out" people, the french are never quick at these things!
I cant help thinking Low G! Mast bumping!

RIP guys!

H

[Vertical Freedom]

RIP sincere condolences to our lost Rotory Brothers.........

sadly no surprises here....... this sadly is a very common occurrence with this brand machine....:mad: welcome to the world of the 'Crapinson Flimsicopter' :yuk::yuk::yuk:

Happy Landings :cool:

VF

[topendtorque]

And condolences too from this neck of the woods. It sure would be nice, but perhaps not crucial to find out at least what dash number the blades were, but heck anything, heart attack major collision with a bird who knows, none of us do at the mo, it's just that sometimes little details like dash numbers of major or minor components are left off investigators reports, mostly because investigators are not skilled often in helicopters where it can matter a great deal.

Keep up the photos, great catalogue. Recently read a book, "Bugles and A Tiger." A brilliant piece by a well known author, no doubt you've read many of his works and details the every day functions of many of people in your neck of the woods. Mighty tough hombres and of course world renowned as very fierce warriors..

BTW when you stick it into these R22's would you mind doing it tongue in cheek, as most do, and you may have noticed that many of us have questioned the safety on a pro-rata basis of the squirrels of late also.e.g. your own very brilliant save from an emergency my have been as a result of an overlooked AD ???????????????.

[Arrrj]

Blakmax,

The door comment was related to another post on this thread. The new Robbie blade data is available via "google"...I would be interested in your opinion.

TET,

This machine was a 44, not a 22.

VF,

I just spent 2 weeks in India, returning to Sydney today. What a fantastic place - I can see why you love being in that part of the world.

I always wait for you to make a comment about a Robbie accident...but maybe you should be a little more analytical...in AUS the rate for heli accidents prorata is far and away weighted towards other brands - particularly Eurocopter. Stick to the facts and your input on this matter (in isolation) would be well welcomed.

Arrrj

[Reely340]

Speaking of accidents vs. manufacturer.
Is there any publicly accessible (internet) source that keeps a tally per year of accidents/fatal/minor vs. Brand ? Of course one would need the number of registered aircraft of each brand to draw any conclusion...

But then again, one would need a pilot-error/other-persons-error/aircraft-caused column in that statistics as well: If the ground crew tugs on the cable and pulls it in your rotor-disk it's neither pilot nor manufacturer, that is to blame.

I'm in no way well informed but the number of proven or alleged cases where the machine failed seem to be highest with Robinsons (SFAR73, mast bumping, mast rocking, "requiring" a governor...). I just don't hear that amount of technical issues reported about Enstroms or 300C(B(i)) or 47Gs.

But then if there were 1000 times more R22/44 flying than Enstroms+300C+47G combined it would be natural to constantly read about then. Hence my request for statistics accident data.

P.


P.

[blakmax]

Aaarj

Looking at the blade design is a waste of time. This is not a design issue, it is a processing issue, and I know RHC do not divulge data on their processes. Even the best design in the world is hopeless unless the bonding processes are sufficient to provide log-term bond integrity. Maybe RHC has changed their processes. Only time will tell.

For my two cents about Robbie bashing, my concern is with the deficiencies in regulations relating to how bonded structures are certified. This is a universal problem, not just limited to RHC.

Regards

Blakmax

[rotorfossil]

Sadly in my view, one of the most likely scenarios is hardly ever discussed it seems. That is - failure to properly manage carb heat (doesn't apply obviously to Raven 2), governor disguises problem until the donk actually stops, confusion, don't lower lever quickly enough, rotor blow back, hits tailboom and general disintegration.
On the occasions when I have caught people by surprise with a simulated engine failure, I have rarely seen anyone lower the lever quickly enough, if at all. I have also had three genuine in flight power failures over the years (not in Robinsons) with qualified pilots handling and on two of those occasions, I had to ram the lever down when they failed to do so, and the other was far too slow. This is rather depressing!

[Sug]

Hi,

I just bought my own second hand Robinson R44 and I am very interested in this topic.
As I am a new aviation owner and a low houred pilot what advice can you guys give me to make sure I don't end doing the same thing as the R44 in France that crashed ?

I have been getting used to my new bird and have been doing low level flying today as we have not had very nice weather in Ireland.

Thanks.

Also, is it ok to land on top of a mountain do people know? There is a mountain near me with a church on top and I am just wondering could I land on it or are there winds etc I need to watch out for. I know by right I should do one of the mountain courses but wher I live the mountains are not that high and no mountain training where I live.

[Lewycasino]

what advice can you guys give me to make sure I don't end doing the same thing as the R44 in France that crashed

Really...?

[RVDT]

Reely340,

Treat these with a pinch of salt from the Flight Safety Foundation,

R22 (http://aviation-safety.net/wikibase/dblist.php?AcType=R22) 502 occurrences ~ 330 fatalities, May 1980 thru Aug 2012.

R44 (http://aviation-safety.net/wikibase/dblist.php?AcType=R44) - 325 occurrences ~ 273 fatalities, Jun 1993 thru Sept 2012.

[roondog]

Sug, you need to know how to fly a helicopter, before you actually fly a helicopter.

[Reely340]

@RVDT
So an average 15 fatalities(!)/year.
How did you get the site to list accidents by aircraft type? If I go to Database and then piston aircraft I don't get any helicopters listed?

edit: google is my friend: one needs a 300C crash then one gets the listing.
Hughes269 and offspring (http://aviation-safety.net/wikibase/dblist.php?AcType=H269)

Not differenciating fatal and non fatal accidents, (anyone care to sum the 300C fatalities on the 8 pages? ;))
they've got 732 accidents listed for all 269/300 variants in 48 years
e.g 15.25/year vs. 16.7/17.1 per year for R22/R44.
Basicall the same, seems to be a nature's constant :E

Interestingly the R44 had more accidents/year than the R22, let alone 300C :suspect:

[RVDT]

Reely340,

I mentioned to be careful with the numbers.

Averaging them over a year makes no sense at all.

Lies, damned lies, and statistics (http://en.wikipedia.org/wiki/Lies,_damned_lies,_and_statistics)

[Pittsextra]

I wouldn't fly in a Robinson for the reason that there are a great number of accidents which contain statements such as "eye witness say they heard a bang...then saw the aircraft disintegrate..."

Carb heat, pilot mishandling, rotor blade delamination or something undescoverable it doesn't matter when the end result is the same.

Forget backing the data up over 10 years, just look at 2012 and you'll see something similar. These things go down with novice pilots, experienced pilots and student/instructors on lessons.

Fans of the marque will come back to numbers built/ how cheap they are etc. A young motorcycle rider was looking to get his first helmet and asked how much he should spend on his new lid. "If you have a £50 head then buy a £50 helmet...."

[topendtorque]

My apologies for post 21, the address bar should have styled in VF for Verticl Freedom.

Pittsextra and oths, re;-

Fans of the marque I guess well, yeah fans of the marque would first of all not talk about carb ice in a fuel injected Raven II. They would have also known that most of the marque these days are equipped with automatic carb heat control as long as it's not locked off of course.

I agree totally with rotorfossil and have put my accounts up before of those who fail to do the elementary "push down on the lever" when the music stops. I mean really, have these people ever played musical chairs as kids! Talk about a protected upbringing. Where was the headmaster with the birch when you were too slow to grab a chair, savvy - no prizes for second place dumbo.

Sure, I also went right to the limit with a mustering 1800 hour pilot, first time up with me, asking twice "can I show him some autos." I complied. I was scared witless at 82% before I got it going back up-hill. Now I know, those who ask more than once have no f'n idea, cos - they - were - not - trained.

Sure Pitts, I can come back and talk about numbers built, absolute paucity of training standards and those ill trained persons just happen to be driving a Robinson when something happens, why blame Frank for that? You need to get real, perhaps your experience is limited.

I can talk about 42 times onto the ground not of my own choosing only three of which were in Robinson products, the rest in the old fable. You name it - freewheel, fan drive, rocker shaft fell out, through bolts broke, all four damper clamp bolts parted company (that was F'n scary why I am still here I don't know) another day at refueling I notice the fore and aft swash plate bolt broken off and halfway out (another cup of really strong coffee) and ( you may have noticed there was an AD for dash numbers of those bolts as a result of that), T/'R drive shaft popped once cos someone had put the coupling at the wrong distance, fuel pump seal lets go - pumps fuel all overboard in 45 mins, Cylinder head starts panting - stupid sod wasn't even being pushed, stuck valve problems by the bucket load before our engine shop had a precision line bore drill, M/R blade outboard twelve inches delams and I sit out not five minutes from base cos no "B" would answer the radio, then there's the simple things like turbo failure, w'gate fell of, one exhaust elbow pipe fell off at - ermmm maybe a tad above max gross -over real rough country, oil pipe broke on xmon then pored all over the turbo- fire in flight, dashboard shorted out at night - cough, did I say that - electrics off and small panic, magneto idler shafts x 2 broken, and so it goes on - seldom was there repetition. Sorry to bore you but it's in the training, you are prepared because you were trained for an emergency it is no big deal. Be capable of attending to the basics and live another day.

Don't blame the product when the operator and particularly the ab-initio instructor may be at fault or just totally missed it, and as I illustrate, Frank's got a long way to go to catch the '47's, and other products. From where I sit he's lookin' pretty good and you may have a long way to go.

Oh and I should put a shot across the bows of this outfit that Rivet refers to, as I have done before.

Flight Safety FoundationWhat have these dudes done except polish chairs with their posteriors and publish figures? Have these faceless people got out and started pushing people around with their findings? If they cannot do that then surely they should be disbanded and get some people in there that will, to tighten standards, and save lives of course.

In the meantime i do sincerely wish the investigators a clear head and an open mind on the subject of this thread. For the bereaved, hang in there have faith, please try to keep calm.

cheers Tet

[Dick Sanford]

Well said TET. We need to do more to get pilots to attend flight safety meetings but of course when you know everything, there is no point!

[RVDT]

Captain TET,

I could add to your list but them days are over I think and it's time to chalk up another White Can.

I just simply answered Reely340's question for him to the best of my ability to use the interweb.

About Flight Safety Foundation here. (http://en.wikipedia.org/wiki/Flight_Safety_Foundation) Which is a free non profit organisation.


If you peruse the info for the R22 you can probably see where the training courses run by the company and approved operators kicked in. That was mandated by the FAA SFAR 73 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/0/C039C8820E83B2F4862578940053960F?OpenDocument) and is not universally adopted unfortunately.

As with all of these things and in your own case of 42 incidents to the ground I would suggest were not all attributable to old Mr Bell or Lycoming directly either.

With most decisions you would agree that the informed one is no doubt the best. These days there is more information freely and readily available and can sometimes be too much and taken the wrong way I guess.