Robinson R22 Corner [Archive copy]

[Rotor1]

24xray.
-------------------------------------------------------------------------------
......some lucky 20 hour students have soloed in turbines with low entretia............
-------------------------------------------------------------------------------


I thought b206's and the like had high enertia blades ?


rotor1

[RDRickster]

RHC Safety Notices 38 & 39...

For those that don't subscribe the RHC POH update service, two new safety notices were issued in July (I received copies of both today). SN-38 addresses training accidents during autorotations by outlining decision making criteria and ways to minimize student fatigue. SN-39 addresses unusual vibrations that may indicate a main rotor blade crack. This last Safety Notice is almost an exact copy of an R22 Safety Alert letter, issued 25 Jun 2002. Please refer to the RHC Safety Notice for details.

In my opinion, I believe SN-39 is the precipitated by the recent R22 crash in Oz. Hopefully, a formal Safety Notice (now included in the POH) will raise awareness. Of course, that doesn't do much for the poor chap that happens to fly a ship with blades that are far beyond their replacement time. Again, this last paragraph is personal speculation (first paragraph is fact).

[RobboRider]

More unhappy news from the AD.

I heard today from my LAME.

CASA still has 14th August as the dedline for the eddy current testing on all blades with more than 1500 hours.

Still no word from RHC on the protocol for actually doing the test. Apparently they are unlikely to have any protocols done till after the 14th deadline has passed.

I was booked to have it done on coming Monday, the LAME doing the tests was expecting some word on how RHC required the bolt removal and replacement and re-epoxying up the countersink for the bolt head. But no word so testing cancelled. And I was planning to travel half-way round Oz the following week.
Anyone heard anything to the contrary that might brighten up my day?

[RobboRider]

Latest Info I have is "Yes but maybe no...."

I emailled CASA today and got back a very quick reply from David Villiers the head of the Airframes section.
Basically he confirmed that the AD requires removal and replacement of the bolt but that RHC hasn't given an approved method for doing it.
The factory is closed for summer holidays and he has been unable to get onto anyone who can advise them about it.

CASA are going to bring out a further ammendment to the AD in a day or two but he says he doesn't know (or can't say ) what it will say. He did say they are aware of all the effects it will have on the industry and that the new AD will be a temporary measure to keep things safe until RHC can advise CASA about the problem.

"Watch this space!" is all I can say.

[helimatt]

G'Day Robborider and Mr Selfish

AD/R22/31 amendment 6 has just been released (Fri 8/8 in the pm)
The long and the short of it is that it states that any R22 that has conducted more than 50 hours mustering must have it's MR blades retired before 1500 hours time in service. It states that the eddy current inspection has been removed on the advice of the manufacturer.
It also goes on to say that any blades that are retired at 1500 hours should be retained "as future developments may enable them to be placed back into service"
Full details are on the web site www.casa.gov.au

[RobboRider]

Yes, I got the AD sent to me by CASA when they promulgated it.

Its going to ground half the fleet in because there aren't enough new blades available to cover the replacements needed and I'm told there's a waiting time of about three months. I haven't made my own enquiries yet but if it's true there's going to be lots of claims for compensation flying round.

They claim in the AD that the mustering puts more stress on the blades therefore the life is being decreased to 1500 hours....but all the reports of the 3 crashes have said the blade lives were far in excess of 2200 hours for two machines and enough suggestions exist to say that probably the third was the same.

So now operators have to buy non-existant new blades (just like we had to do non-existant tests in the first 5 of 6 ammendments) to prevent a problem not known to exist in blades used in accordance with manufacturers specs.

The operator who is not complying will continue and the rest will suffer.

But given the fact that CASA can't work out what they are doing (6 ammendments to an AD in less than 3 months makes you wonder about competence) there'll be more ammendments as they knee jerk to the likely outcomes of their previous knee jerks.

[sprocket]

The operator who is not complying will continue and the rest will suffer.

RobboRider: I agree.

I wonder sometimes at the mentality of the authority. They are writing up more directives/amendments when a few operators/owners are apparently ignoring the directives in the first place. These same ‘few’ will obviously adjust the "recorded" mustering hours accordingly to remain within the requirements of the AD and unless they can be caught, someone else will usually suffer the consequences.

How the hell can that fix the problem?
It’s the same as trying to put out spot fires without extinguishing the source.

CASA is in between a rock and a hard place when it comes to issues like these and the toothless tiger syndrome becomes the norm.

[Lu Zuckerman]

Blades don't have to be abused to break.

In a previous post on this thread I posted a NTSB report on an R-22 that suffered a possible blade separation. This helicopter was privately owned, it was most likely not abused and the blades were most likely well within their specified operating life. It could be chalked off as an infant mortality failure, a possible manufacturing defect or any of several other causes. Whatever the reason it shows that blades can fail when least expected. (Murphy’s law).

[sprocket]

Whatever the reason it shows that blades can fail when least expected. (Murphy’s law).

That may be true Lu, and several manufacturers can testify to that.
But the situation (at least in Oz at the moment) is that if the blade life of an R22 is exceeded, you can expect it to break. It seems to be a trend and is not a random act of suprises.

....having said that:

1. Can anyone confirm/deny that this blade cracking has occurred in blades that are within their lfe limit?

2. Does lowering the mandatory life of a blade, stop people from exceeding it?

[Autorotate]

With all the rumours blaming the mustering industry, is this a general broad description of the industry, or are there specific operators in question.

Just seems we are tarring them all with the same brush, when there seems to be quite a few honest and above board operators out there.

In NZ we had problems with an operator selling bogus parts, he was jailed but it just amazed me that an operator of helicopters was caught doing it. Could understand parts supplier but someone who put his own people into machines that had U/S parts on it

[Dave_Jackson]

Just an idea

Why can't the helicopter industry develop a small self-contained electronic device, which is located within the sealed gearbox. The gearbox could easy provide the electricity required at the same time the revolutions are counted. Additional relevant data can be obtained from sensors within the device.

Also, this device does not have to be expensive, because it plays no roll in the functioning of the craft. The device can be read by sticking a jack into a socket and there would be no way to change the prerecorded data.

[Lowlevldevl]

Sprocket

-if the blade life of an R22 is exceeded, you can expect it to break.-

Is that really the case? Other posts in this thread have recounted how a number of R-22's used in mustering in Australia have exceeded their hours by a factor of 3 thats 8000 hrs. I have personally seen several that have done 4000, one that must have been up around 6000. The accepted practice was to write up 1 in 3 and that not to include ANY non-revenue. If you were to find out what number of Robbies have been operated in Australia on mustering ops over the past 20 years and apply a few statistics I think you would see that in fact blade failure is far and away the exception rather than the norm. From memory(and its a bad one) there have been only 3 catastrophic failures of R-22 rotor blades. One of those was poor old Shaun Murphy and that one was put down to poor machining of a blade bolt hole. Laboratory testing of the blade showed it had exceeded its hours by only 10%, 200 hrs. If he hadn't exceeded his hours it wouldn't have happened, however you can't ignore the fact that the reason the blade failed was that there was a fault in the manufacture/ repair(can't recall exactly which). There was another one early on which delaminated because the Robinson blade bonding room was the same as the blade painting room and the glue didn't stick to the spar properly bacause of the overspray on it. Then there was one(can't remember the poor guys name) in south central queensland which was obviously blade failure/ separation. I haven't seen any reports on that one so can't comment on the cause. And now theres the Sydney incident. It would be impossible to put a realistic figure on it but lets say the R-22 fleet in Australia has had 150 machines operating 1000 hrs a year for the past 15 years. Thats over 2 million really hard hours. Now all of my figures are just educated guesses, and I'm sure there are many out there who can show that I'm wide of the mark on a few, however I hope you can see where I'm trying to go with this. I believe that if there really was a problem with R-22 rotor blades, we would have seen a lot MORE blade failure accidents.

Don't get me wrong, I in no way condone exceeding ANY component life. I used to have a Hughes 300 mustering in Australia and I kept my maintenance on time as much as I could. Bloody Robinsons sent me broke. No way I could compete with young ex-ringers totally ignoring maintenance requirements and burning Mo-gas. Am I p..ssed about that? Damn right. But having seen how those poor little Robbies were abused over the years has certainly given me some respect for their design.

Interesting that no-one commented on LU's post about the private machine in the U.S throwing its blades. Obviously doesn't sit well with those who just want to dump on the mustering guys.

[Autorotate]

Lowlvldvl.

I actually went and spent some time watching HeliMuster at VRD and was pleased with what I saw there. Johnny Armstrong even took me to their "dump" on the property and there must have been over 200 R-22 blades, as well as a couple of wrecks, so obviously these blades were trashed when out of hours. Have some great pics showing these massive piles of R-22 blades in a big heap - would have been a bogus parts guy's wet dream come true.

I honestly think that the mustering industry have picked up their game over the past few years - unless someone here wants to outline otherwise.

[Lowlevldevl]

Autorotate,

Yes,I certainly agree that the majority of mustering operators have improved their act over the past few years. Getting tough with one or two seems to have had the desired effect on the rest.

Unfortunately though, some of the organizations who are happy to be held up as shining examples now are the same ones who started the whole hour cheating culture in the first place. Anybody remember a certain B-47 ostensibly registered VH-GOD?

[slowrotor]

blade cracking

Lu,
Is it possible to inspect blades for cracks before the blade fails?
Someone told me that blades are subjected to whirl testing on a stationary machine and then if the blade fails at, say 4000 hrs, the life limit would be set at say 1000hrs.

I bought parts for an old Hiller 12 (time life tension/torsion straps) the dealer said they were knew but they looked more used than ones I had.
Trust doesn't cut it for me,I like to have parts that can be inspected. Otherwise a small chip should be bonded inside the blade (like my cat has under the skin)with a G-switch and timer that can be read by a simple scanner.
Can blades be inpected or do they just fail at random without warning?

[sprocket]

Lowlvldvl: This is a link to the Qld crash report.

Click Here

A quote from the report …….

Helicopter history
The helicopter had recorded 2,124.6 hours time in service (TIS). That total flight time was derived from the helicopter hour meter, as the pilot's logbook and helicopter maintenance release were incomplete. The last flight entered in the pilot's logbook was on 2 July 2000, 27 days prior to the accident. The last entry on the helicopter maintenance release was 4 July 2000, at 2,102.4 hours TIS, 25 days before the accident. Those were the hours at the time of release to service following a 100-hour inspection, completed on the same date and TIS. No flight entries had been made from that date until the time of the accident.
Helicopter operations
There was anecdotal evidence from witnesses who were familiar with the operation of the helicopter that suggested it might have been operating more hours than was being documented. A review of company and helicopter records was completed to substantiate helicopter operating hours. That review comprised analysis and comparison of company customer flight time and fuel invoices and helicopter spares usage versus recorded helicopter flight time. That evidence suggested the helicopter operating hours were being under-reported and supported the anecdotal evidence of the witnesses.

There is always a possibility of manufacturing design or faults being a contributor to the three blade separations (in Oz) and even if this was the case the separations still occurred after the life limit of the blades were exceeded. Apart from the manufacturer, two common factors with the failed blades are:
1. Mustering time
2. MRB Life limit expiry
3. Anyone care to add some more?

For the benefit of overseas flyers, the last para in amendment 6 of the AD states ….

The original fatigue life set by the manufacturer, and specified in the helicopter’s airworthiness limitations, was based on a load spectrum that took into account normal operations and training use, but did not consider the more severe flight loads imposed by aerial mustering operations. Consequently, the retirement life specified in the airworthiness limitations section of the maintenance manual may not be suitable for MRBs that have been used in an aerial mustering role. It is expected that Robinson Helicopter Co. and/or the FAA will provide a more detailed analysis of the impact of aerial mustering operations on R22 MRB fatigue life. When such an analysis becomes available, the blade retirement life for helicopters engaged in mustering operations, and this directive maybe revised again.

(I’m sure Lu might have something to add here)



Dave: There are some suggestions already, like yours in previous pages of this thread. The idea might work, but I don’t know how many operators will “take” to the initial outlay to have something like that installed.
Perhaps it could be one way for operators to “buy back” their 2200hr MRB life.

On the subject of Lu’s mention of the US blade accident: It refers something other than actual blade failure. The blade/hub bolt showed signs of failure (the way I understand it). A different set of factors need to be considered here as these bolts are subject to removal/reinstallation sometimes, but I know Lu has always had doubts about the design of the M/R hub which incorporates the said bolt.
I will be interested in the final outcome of the investigation report …..as long as Heliports monitoring of Accident investigations works!

[RobboRider]

By Lu's own description he doesn't have anything.

A helicopter crashed without witnesses. The machine was found to be completely wrecked with one blade separated in the MIDDLE of the blade and one blade separated at the root. The machine could have had any number of things go wrong with it. There is no evidence or suggestion, except in Lu's "anti-Robinson mind" that blade separation occured in the air or prior to an impact while in flight.

In fact there is no evidence it actually left the ground - a dynamic roll-over with blade impact can just as legitimately be an explanation.

At present we have a situation in Australia, discussion of which does not need Lu's consistent anti-Robinson bias stirring to muddy the waters.

[Lu Zuckerman]

Well, excuse me.

To: RobboRider

Do I detect a bit of animosity in your comments? All I did was to post an NTSB report regarding a crash of an R-22 which implied based on the location of one blade section relative to the primary crash site that blade separation may have taken place. In another post I stated that blade failure could occur at any time and it could result from a manufacturing defect or any other reason and when it does happen it could be chalked up to “Murphy’s Law”. That is until the exact cause has been determined.

As far as testing there are several methods depending on where the potential failure is located. There is a tap test to determine if the bonding surfaces have separated. There is the Dye Penetrant type test to determine if any cracks exist, there are also visual inspections using high powered magnification and this testing could also involve eddy current testing or even magna flux testing. In most cases airframe manufacturers do not include these tests in the maintenance manual. Tests of this type are created based on a field failure or discrepancy report and once the test has been sent out via an AD the test will be incorporated into the maintenance manual when it is updated (usually every six months).

Now to set everybody straight that feel that I am biased against the Robinson design let me assure you that I am equally biased against Bell, Agusta or any other Aerospace company that sells their products fully knowing that there are problems in the design. These problems could relate to maintainability, reliability or even systems safety. The reason that most people on this forum object to my postings relative to the R-22 / 44 is that they have a vested interest in the Robinson helicopter and they could never admit that there are potential problems that could result in death and destruction. I have been working in this field since 1968 and I believe I have been doing a pretty good job.

[Autorotate]

NZ Emergency AD on R-22 Blades PLUS ++

Was just talking to one of the local operators and NZ CAA have issued an AD today saying basically the same thing as in OZ, if your machine has a history of mustering then its 1500 hrs time ex for the blades, until further notice.

Now an interesting thought here is, NZ Robbies have been used extensively for venison recovery (Deer hunting) and the same scenario where hours arent logged in many cases. Now if the AD covers mustering, then in NZ, in my opinion, it should also cover any R-22 thats been on venison recovery as this part of the industry has the same problems as the mustering industry in OZ.

Comments anyone.

[Autorotate]

For those that asked here are a couple of pics of retired R-22 blades at VRD. These ones aint much use. Few Bell 47 parts in there as well.