Raf rotor blade cracks!!!!!!!!!!

I have never liked anything about the RAF hub bar. The blades themselves are appealing in that they will lift a heavy load and they aren't very expensive. - Plus they make good wampa wampa sounds! :) - But the hubbar scares the poop out of me and this drives home my fear for it further.
 
Truth or what

Truth or what

I have seen hardended drive shafts with grade 9 bolts snap after being serviced by dummies with impact guns. NOTHING is indestructable. Stupidity can and will find its way into any situation. Knowing just a few things besides, oh its a questionable design could explain a whole lot more. I do not know how many blades are in service. I do know that RAF would be guilty of murder if they turned out a ROTOR SYSTEM that they KNEW was marginal.

The hub bar may have issues when improperly serviced but does that make it a dangerous part ? Just because I cannot beat it with a sledge hammer and torque with an impact gun does that make it a defective design ?

I dont want to play devils advocate but Something tells me there is more to this story that meets the eye.

Does this owner mount his blades every time he flies or does he leave them on ?

Did he torque the bolts with light oil and a quality torque wrench or does he honk on a dry assembly ?

Has he ever hammered the bolts in and out to get the assy together or apart ?

We need more information. Nothing is fool proof or indestructable.

I was just talking about this very thing 2 nights ago. There was a L1011 that lost an engine and the pylon that was attached to a wing. Everyone was killed in the crash. The investigation revealed that the sheared bolts were a red herring. The mechanics took a short cut and used a fork lift to install the engine on the pylon and the job was not completed in time. The fork lift sagged overnight and the weight of the engine flexed the mounts and cracked them. Upon take off the engine torqued under full power and rotated up and back and ripped off the wing and all the hyd systems went to shit. Whos fault was it?
Bad design ? Operator error ?

We need more info before we romp on RAF blades.

Chuck why is this the first time I am hearing of crack in a hub bar ? I have been with the PRA since 1999. ??? I have heard of stress cracks in the blades but not the hub bars.

Jonathan
 
zeeoo said:
Chuck, not being a gyro pilot (yet),
i certainly understood the facts you tellme.
just reading about RAF here, i wouldnt buy one..
yes this part really looks poor engineered,
but my opinion, i repeat it, is that all the short and flat blade grips on flat blades are a potential source of failure (there was a thread here about vortech blades on a mini 500)

EDIT : apologizes to BRIAN and DAVID, i was wrong about Xray, now i know, thanks
Click to expand...
where can I find this info,I have Vortech blades on my Scorpion,and to say the least not hearing good things about them.
they do have great lift, but I am worryed about the long term use of them.
 
Jonathan :

I have seen a crack in an RAF hub bar. In fact I found it doing a walk around inspection on Duane Hunn's RAF before he arrived at the airport.

It was on Duane Hunn's RAF at Brookville Ohio, I believe it was the last year that they held the PRA fly in there.

I also know of one other cracked RAF hub bar here in B.C. , however I did not see it myself.

I was one of the people who put pressure on RAF to warn their customers of the cracked hub bars. They finally sent out a letter about doing a hub bar exchange.....long after they knew of the problem.

As to why Duanes Hub Bar cracked why don't you ask him?

I do know that they tried to cover it up. And I do know that Duane and Dan Haseloh really tried to put the pressure on me to keep quiet.

Chuck E.
 
I haven't seen it mentioned here or on Norm's conference but at a PRA Conference somewhere around 92 -94, Ron and Steve Menzie had a RAF redrive jack shaft snap while at altitude. Fortunately the prop left the vacinity of the gyro without touching anything. I took pictures but can't find them at the moment. I do remember the break was about as smooth as is it could get without actually machining it.
 
"I do know that RAF would be guilty of murder if they turned out a ROTOR SYSTEM that they KNEW was marginal."

They sold over 30 ignition systems that failed and that they were notified about, and they still kept selling them without saying anything. It was only after a poll on Norm's Forum that over 30 of us discovered we had faulty ignition systems, designed by Peter, who has an extensive background as a truck mechanic.

Not only did they keep selling them, they told almost everyone that called in about a failure that they were the first one to claim an ignition failure and it was most likely water in the gas or lack of carb heat. They said that there was nothing wrong with the ignition systems. One trusting fool believed them, and after draining his tank and checking that his carb heat worked, went flying again. He rolled it over while trying to land in a plowed field after the ignition system quit again.

Without doubt, they are guilty of despicable, dishonest and immoral behavior in more areas than one. They lie, even though their lies put people's lives at tremendous risk. How anyone can defend them and their shoddy designs, parts and immoral rotteness is beyond belief and comprehension. I guess even Attila, Mussollini, Hitler, Stalin and Tojo had their fans and apologists. ("Well, Hitler was a pretty good Joe. He never threw me or my family into an oven.")
 
Last edited:
"I haven't seen it mentioned here or on Norm's conference but at a PRA Conference somewhere around 92 -94, Ron and Steve Menzie had a RAF redrive jack shaft snap while at altitude. Fortunately the prop left the vacinity of the gyro without touching anything. I took pictures but can't find them at the moment. I do remember the break was about as smooth as is it could get without actually machining it."

That's why anyone with any sense will do the Jim Butler designed upgrade. I can E-mail engineer-drawn specs to anyone that wants to avail themselves of them. And get this.....they're free.
 
Vance posted:

"I don't think of the big reduction plate as quite so critical to flight saftey."

Vance, now you got me P.O.-ed and I better not ever come face-to-face with you at some..........just kidding. I disagree. If that thing starts chucking chunks of aluminum, they will go right into the prop, and quite a few critical components are reliant on that thing staying together....like just about the whole redrive system and starter.

Vance, no one that posts here is on my bad side....honest. When I hear crap that RAF pulls, I've been known to take it out on the message-bearer rather than the source, like Jersey Wing. It's not right and I've vowed to never ever do that again, at least 28 times now. All I can do is apologize again to Jersey Wing and anyone else that I jumped on. I'm not trying to be an ass, but the safety issues are a great concern to me and when I read of someone trying to blow smoke up someone's ass, I don't always think in a polite manner for awhile, as it makes me livid when I hear of people or companies showing a total disregard for other people's safety and lives by telling them bullshit that could kill them. I will try to do better in the future and I hope there are no hard feelings. I didn't mean to be so caustic and insensitive and I apologize. :o
 
Last edited:
Paul, thanks for bringing this hub bar failure to our attention. In my opinion the occupant/s would surely have died the next flight. Its a terrible thought. I wonder how many others out there are either cracked or about to crack. I mentioned on this forum after a previous failure, that the only surprising thing is that it hasn't happened sooner,
The 500 hr life too is worrying also. To give a 1.5 safety margin you would have to limit the blades to 333 hr then allowing for manner operated and the "scatter factor" in the failure analysis of aluminium, would bring that figure down to something that would scare the sh.. out of any serious RAF Bladed Pilot.
 
animal said:
where can I find this info,I have Vortech blades on my Scorpion,and to say the least not hearing good things about them.
they do have great lift, but I am worryed about the long term use of them.
Click to expand...

tim, i performed a search, it s in the archives, and SORRY it was Dragonwings, not vortech

https://www.rotaryforum.com/forum/archive/index.php/t-2323.html

i just quote c.Beaty :
C. Beaty09-19-2004, 03:40 PM
Dragonwings on Mini-500

First, I must state categorically that a stock set of gyrocopter blades must not be mounted on a Mini-500. The connection between blade and grip isn’t strong enough.

cheers
 
Last edited:
tim (mceagle), talking about failure analisis, i performed it with solwidworks, and, surprisingly, the hub bar can hold on good efforts (THEORY), but jerseywing explained very well the "vee" test.

i m just amazed RAF didnt put some hub bars rotating during a month (500 hrs) with fake blades, por balanced, shaking the mast, just to see for REAL if there is a source of failure, it s not a matter of cost for them but of will...

i think also an approximative design can be "forgiven" on an amateur construction but, if you sell as an official "aircraft manufacturer" you must have a serious quality/design control, or you are not honest.

i repeat it : get out of bensen's design, design a true tilting rotor, ask dennis fetter or other light helico designer to draw a light gyro rotorhead..

IMHO

thank you
 
Last edited:
The day Ron Menzies lost his Jack shaft was the day I found the cracked hub bar on Hunn's RAF.

Ken mentioned the broken jack shaft, hell there were several that cracked and RAF finally put out another recall on that part, but they moved to a bigger engine around the same time.

Very few of you were around when these gangsters first started screwing people out of their money up here in Canada, the list is endless.

I was subpoenaed as a witness for the crown in a case against RAF around 1994. By the way RAF was found guilty of falsifying of documents. What more proof does one need that they are liars and cheats?

Don is such an automatic liar even under oath that his testimony was totally disregarded in his attempt to divert the truth from the tribunal hearing the case.

In all my years of being in aviation I have never met such dishonest lying people as the RAF management crew.

By the way how can any of you RAF defenders defend Duane Hunn and Jim Logan's refusal to explain all these allegations?

Chuck E.
 
Victor: "i repeat it : get out of bensen's design, design a true tilting rotor, ask dennis fetter or other light helico designer to draw a light gyro rotorhead.."

What do you mean by "a true tilting rotor"???
 
Is There An Alternative Hub Bar

Is There An Alternative Hub Bar

Is there an altermative hub bar that one could purchase and substitute fir the OE RAF hub bar? and how do they perform in comparison? Are they as adjustable? Do they come with instructions for adjustment?
 
Victor, don't be surprised. A few years ago, they came out with this "explosion-proof" filler for their gas tanks. They even got an award for it at Oshkosh. But, they never even bothered to put a piece of it in a mason jar with some gas in it to see if it was impervious to gasoline. It wasn't and started falling apart in the tanks, causing several engine outs by clogging the lines. I don't recall the exact number. Even an idiot would see if it held up in gas before stuffing it in all the fuel tanks that went out the door.
 
Last edited:
quadrirotor said:
What do you mean by "a true tilting rotor"???
Click to expand...
something like the B206 or at least the B47, teetering point a the up of the mast, true cyclic control, true undersling, d3 angle.

a rotor hub designed properly, a pre-serie for destructive tests
as Ken suggested, just ask 2 or 3 students in engineering to have a look, it's quite free and reliable..

there are alternative techniques to mono-block alu bars like sandwich or steel lamina, it doesnt cost a lot to have a reinforced progressive blade root.
a full composites rotor-hub is not only feasable, but much more reliable in fatigue, dont tell me the mold is that complicated and rolling unidirectionnal fiberglass around struts is not that complicated... even delaminating is visible or detectable easily than cracks, and much more tolerant before complete rupture. IMHO

thats an interesting brainteaser, indeed :D

thanks andre
 
You must log in or register to reply here.

Similar threads

W
Swedish yoke
3 4 5
Replies
83
Views
16K
kolibri282
kolibri282
PeterFromLA
Kallithea Oshkosh 2022 Trip - Departing from Mentone
Replies
7
Views
2K
PeterFromLA
PeterFromLA
GyroRon
Flight review of the Gyro Technic gyroplane
2
Replies
33
Views
65K
Sv.grainne
Sv.grainne
gyroplanes
Captain Johnny Miller
Replies
1
Views
2K
GyroCFI
G
Brian Jackson
Barry Mounts upside-down?
2
Replies
25
Views
4K
Brian Jackson
Brian Jackson
Back
Top