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Robinson helicopters added to safety watchlist

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Robinson helicopters added to safety watchlist

Old 27th Oct 2016, 22:46
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Robinson helicopters added to safety watchlist

Robinson helicopters have been added to the Transport Accident Investigaton Commission (TAIC) safety watchlist.

The Robinson helicopters have been formally added to the Transport Accident Investigation Commission's (TAIC) official watchlist of "most pressing concerns".

The helicopters have been plagued by so-called mast-bumping incidents, in which the main rotor blades strike the cabin, causing the helicopter to break up in mid-air.

Fourteen such incidents have been investigated since 1996.

Commissioner Stephen Davies Howard said there was a real risk of further accidents.

"We are extremely concerned at the number of people dying as a result of Robinson helicopters crashing in New Zealand [and] we need to understand why."

People flying Robinson helicopters needed to be aware of TAIC's concern, he said.

"The commission is seeking a concerted action by the regulatory authorities, the manufacturer, operators, instructors and pilots, to promote the safe operation of Robinson helicopters."

Deaths place Robinson helicopters on watchlist | Radio New Zealand News

Two more pressing concerns: Watchlist 2016

Still feel safe flying around in one??

Last edited by skippers; 27th Oct 2016 at 23:00.
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Old 27th Oct 2016, 23:15
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Well well......smoke me a Kipper Skipper....who'd have thought that?
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Old 28th Oct 2016, 03:04
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I'm shocked NOT about bloody time
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Old 28th Oct 2016, 07:26
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Is that only in NZ? What about the rest of the world? Private owners? Commercial pilots? Lack of training?

Heaven knows I'm not a big fan of Robbies, but I don't think they have more of a problem than any other brand in that respect. Or have they?

Phil
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Old 28th Oct 2016, 07:33
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Interesting definition of mast bumping - I always thought the clue was in the name!
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Old 28th Oct 2016, 11:29
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212, it strikes the cabin after separation from the mast, incurring fatalities even at survivable heights.
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Old 28th Oct 2016, 15:46
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212, it strikes the cabin after separation from the mast, incurring fatalities even at survivable heights.
I find that hard to comprehend? Given that the condition results from a low g condition that requires reasonable airspeed and height to achieve, it's hard to imagine what height above the ground is considered 'survivable' for the occupants of a freefalling Robinson fuselage that was probably doing around 100 kts at the point of seperation?
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Old 28th Oct 2016, 16:40
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And the Crapinson Flimsycopter is not exactly noted for its crashworthiness even when the rotors are still attached.
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Old 28th Oct 2016, 21:16
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Welcome to the G2 era
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Old 28th Oct 2016, 22:52
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I find that hard to comprehend? Given that the condition results from a low g condition that requires reasonable airspeed and height to achieve, it's hard to imagine what height above the ground is considered 'survivable' for the occupants of a freefalling Robinson fuselage that was probably doing around 100 kts at the point of seperation?
There's been other discussions on Robinsons and the teetering head in general, where someone posted the US military reports on the mast bumping phenomenon.
There was a training officer who survived one, but saw his copilot in the Cobra have his face severed by the departing blade.

A lot of those were occurring at terrain following, hence the low-g move as it crested hills.

Not saying this is the case with the noted Robinson accidents, but might be an argument used for this notice.

Also, not every "mast bump" causes separation before the cabin strike.
Example:
Robinson R66, ZK-IHU, Mast bump and in-flight break-up, Kaweka Range, 9 March 2013
Aviation Reports
4.2.1.
There was clear evidence of a severe mast bump and that a main rotor blade had struck the cabin.
The main rotor drive shaft separated under a combination of bending, torsional and inertial effects, resulting from its being driven by the engine while the blades were prevented from turning because they had struck the fuselage.
It seems there's a few instances like this, with cabin strikes precipitating the loss of the rotor.
http://www.aaiu.ie/sites/default/fil...20EI-MAC_0.pdf
The flight from Weston to Sligo, via the Newtownmountkennedy area, was uneventful and routine up to 10:10 hours. Very shortly after this time an in-flight catastrophic event occurred resulting in the disintegration of the Perspex windscreen, as it was struck by the main rotor blades.
...
This event would have caused a critical loss of rotor RPM and very severe airframe vibration and loss of control, leading to the final impact. Pilot aided recovery would have been impossible after such airframe strikes. Finally, just before or during ground impact the main rotor struck the tail boom.
http://www.pprune.org/rotorheads/292...om-strike.html
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Old 29th Oct 2016, 09:58
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212, it strikes the cabin after separation from the mast, incurring fatalities even at survivable heights.
Willy - I don't think that is strictly true - the link you provided to the crash in Ireland states the rotor mast only fractured on impact with the ground - it is usually just the extreme flapping of the blades that gives the cabin/tail boom strikes.

There are reports that we have seen on this forum that show how the pitch change links and arms can be broken by the extreme flapping but the rotor head (what there is of it) can remain attached even during the blade strike process.
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Old 29th Oct 2016, 10:25
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I do not want to get into arguing about the shortcomings or otherwise of Robinsons, as I am now too old to even clamber into one!

I owned one of the first R22s imported into Australia way back when ever it was. The serial number was under 200, so it did not have the tip weighted blades.

It was made VERY clear in the POH that low G maneuvers would very likely at least, result in the main rotor blades blowing back and cutting off the tail cone.

So it is not something new, and it is STILL caused by the pilot. And if the argument is that it can occur in turbulence, it is still a problem that a pilot has an option over.

Frank Robinson(and I have met him),never intended OR envisaged that the aircraft would ever be used for some of the hair brained operations that they are regularly used for.

And I also venture to say that there is probably a big number of pilots around today that would never have been able to afford paying for training themselves, if not for the cost effective use of R22s in those days.
In addition, once you mastered the twitchy things you would never have a problem transiting to bigger machines in the future.
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Old 29th Oct 2016, 14:05
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Willy - I don't think that is strictly true
Yes, not the only cause. I probably should have led with the other quotes first.
It was the one that stood out to me when reading of the early lawsuits regarding the UH1 and cobra.


Frank Robinson(and I have met him),never intended OR envisaged that the aircraft would ever be used for some of the hair brained operations that they are regularly used for.
Yes, I don't think he imagined the amount of R22s used for herding in Australia, for example.

In all, I think it's probably just a step up in legislation from the SFAR issued by the US authorities.
The US might have done the same, if not been more restrictive, were it not a US export product, and the amount of schools that would suffer were they all grounded.
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Old 29th Oct 2016, 15:31
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So Volkswagen has to buy back hundreds of thousands of diesel vehicles because of an emission issue, but a helicopter that has killed hundreds of people just keeps on going?

Am I missing something here?
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Old 29th Oct 2016, 16:08
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Pants brings up an interesting analogy.

If Pants had said "Volkswagen has to buy back hundreds of thousands of diesel vehicles because the drivers keep crashing into other cars, into bridges, and in general losing control and killing themselves and others" then he'd have a point. But of course Volkswagen does not have to do that, nor does any other automobile manufacturer.

Similarly, some cars are much safer than others, both intrinsically (e.g. larger, more airbags, etc.) and demographically (e.g. purchased by older, wiser, more experienced drivers, vs. younger, more reckless drivers, etc.). Indeed, this link is quite interesting:

Driver death rates

Although sadly it does not distinguish between intrinsic safety and demographical effects.

As the saying goes, you pay your money and you take your chances. Some vehicles are intrinsically safer than other vehicles. Mixing it up with large trucks on a busy highway is much safer when you are driving a large SUV than when you are driving a motorcycle. Should we outlaw all motorcycles? Where do you draw the line?

When I arrived for my very first helicopter lesson I knew that the R22 was more challenging to fly and with less of a safety margin than anything that had a turbine and three or more main rotor blades. And, if I hadn't, the SFAR 73 safety lesson certainly made that clear. I assessed the risks and went on with it anyway. I could have decided to spend more money by learning in a Enstrom at twice the price, or even in a 206 at four times the price. I paid my money and took my chances, eyes open. No different than when I made the decision to purchase my first motorcycle (or, for that matter, when I decided to stop riding motorcycles).

So, where do we drawing the line? Perhaps we better start banning a whole bunch of much more dangerous stuff (like motorcycles), first, eh, before getting started on Robinsons?

OK, ready for massive holes to be poked in my analogy...
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Old 29th Oct 2016, 17:44
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Originally Posted by pants on fire... View Post
but a helicopter that has killed hundreds of people
Hundreds? Really? All directly attributable to design/manufacture rather than the way they were maintained & flown?

PDR
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Old 29th Oct 2016, 20:01
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I think the issue here is they don't no what is causing the mast bump in the first place.
Everyone knows that you should not do a low g pushover in a Robbie, but if a helicopter in level flight, in non turbulent conditions has a mast bump, what has caused it?

Quote from TAIC:
In the report, TAIC said there had been "many other fatal mast-bump accidents involving Robinson helicopters in New Zealand and around the world that have gone largely unexplained".

"It is difficult to identify the lessons from an accident and make meaningful recommendations to prevent similar accidents if the underlying causes cannot be determined," the report said.
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Old 29th Oct 2016, 20:03
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Not the first time this has come up:

NTSB Report on R-22 Accidents
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Old 29th Oct 2016, 23:12
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Skippers - the first few pages of the report Gordy links to start to give some reasons - the 'very responsive' rotor system, the unusual head design that allows the blades to flap independently and the unusual cyclic setup are all contributory factors.

Add in a great many inexperienced pilots flying the aircraft and you have a worrying mixture.

The stats for LOC (loss of control) accidents per flying hour are significantly higher for R22.

It does seem that flying too fast in a robbie can trigger events that result in similar outcomes to low G and turbulent conditions - makes me wonder if an excursion into retreating blade stall might prompt an inappropriate control response leading to the mast-bumping, tail strike and rotor separation sequence we are familiar with.
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Old 30th Oct 2016, 01:52
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I had flown mid-size turbines (mostly teetering head) for quite a few years previous to getting in a Robbie for the first time, and after a couple of hours getting used to things like the rapid spin-up of auto revs and a few other peculiarities like the T-bar cyclic, found them to be quite OK.

Been on them pretty much full time for the past 3 years doing all the whacky things you do when teaching CPL courses with low flying, autos from many different speed/height setups and so on, and I'll happily go out on a limb and say I quite like them.

They are built down to a weight and price, but when flown with respect and within their limits, and maintained properly, they're no more an accident waiting to happen than any other helicopter. They are responsive, manoeuvrable, quite good fun to fly and a great training platform for teaching students to think about power and wind.

Sure, they're power limited in some circumstances and can be overpitched, and you can't rule out mast bump with a teetering head - strangely enough just like the B model Iroqouis I did my helicopter training in, and you won't hear people bagging those out very often - it's more like reverence for the Huey (which I have my share of too!) but slagging off of the Robinsons even though they share quite similar characteristics in many respects.
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