Two observations:

1) It appears that the first row of honey comb nearest the leading did not bond like the rest.

2) The leading edge of the skin at the D-spar interface looks like it did not bond with the substrate (darker green areas) as consistantly as in other areas (lighter green/white areas).

It may be that the paint acted as a filler in the area of the D-spar/skin interface preventing lifting of the skin. Lack of sealing in this area may also have allowed moisture entry or other contamination to become a factor.

There's probably a very good reason for it not being that way (hopefully apart from manufacturing cost), but it seems crazy that there's no lip on the skin that fits in behind the leading edge, with pins on the leading edge to retain it in situ as well as the bonding?

Lack of paint should not give a delam such as this. Lack of surface finish including sealing which lead to water ingress followed by corrosion would.
Looks like a straight delam to me.

Looks like.....
 

Yeah, I would say the bostik let go. How many hrs had it done? Saw a R44 throw about a metre out of the centre of the blade in South Africa about a yr ago. The chopper only had 100hrsTT , guy was lucky to get out with only serious broken bones.

Robinson have issued a service letter regarding checking the paint on the bond line.

Johe02
Over 150 posts! About time I clicked here and ordered a Personal Title.


Join Date: Oct 2002
Location: England
Posts: 188 Jeez . . whoever is maintaining/flying that needs their arse kicking.

Paint not allowed to go back farther than the lamination point!

Is this sort of thing the cause of all these de-lamination stories?

Cant blame Frank for this one. .


Please sir, surely you are attempting humor here.
I think all this does is solidify the theme running over most of the helicopter-planet, and that is that Frank needs someone else (i.e. another more-qualified company) to make his blades. His folks certainly aren't getting it done.
Very sad.

Searching the NTSB accident records for R22 & R44 does not show any issues relative to blade delamination.

Any idea of the total number of occurances worldwide?

Hey Snoopy

Join Date: 11th November 2003
PostsTotal Posts: 79 (0.06 posts per day)

Whats your point??

You think its ok to run a Robinson with no paint on the blades??

If the paint comes off they need re-painting.

If you feather the paint early, they last longer.

T'aint rocket science. . :8

Anyone got a comparative picture of a blade with the paint still attached?

BW

Was that machine used on cattle mustering, where positioning flights are not routinely put into the tech log? That blade may well have done way over its time.

Phil

Easy to note that there are as yet no comments form the antipodes. Mainly because every one is

It matters not where it started to delaminate from. I have heard two opinions.

It was also purely co-incidental that sometime on the last flight that the blade gob smacked a bug or beetle of some sort, 3 and 11/16’” on your picture inboard from the tip of the blade proper.

You will notice that the witness mark is not only on the underside exterior bottom edge of the leading edge, but also on the spar material and the underside of the skin. In other words the skin at that time was flexing open just a tad enough to allow that juice to flow in between the skin and spar.

Is Frank the only person on this helicopter planet that believes that bonding stainless steel can be done to perfection without acidic or laser etching, or is this just a routine type (without putting too plain a point on it) of quality control gone missing?

The photograph portrays a very large percentage of material that was never bonded.

We also assume that the honeycomb was supposed to be all the way to the leading edge as well? Perhaps the missing bits allowed flexing of the skin which caused the glue to crack progressively.

There is no sign of prior damage to the leading edge, to initiate this damage.

I think what we see is what we have got, a failure. Why?

No I do not believe that it has done anywhere near it’s time; it was only fitted in November ’05.

For those who comment that there is excessive paint abrasion, yes that certainly appears to be the case for six hundred hours. However, paint abrasion always occurs from the outside in, bonding failures occur from the inside out.

I and many others here would have experienced leading edge erosion to the point that the skin became so thin that it started to break up, but was still firmly bonded to the underlaying spar.
Still Stunned

There's too much money involved for anyone to do anything about it. CASA and the ATSB don't want to know about it.

Just found a closed thread from April - May last year, through the course of the thread there are no fewer than 10 Robinson blade delaminations mentioned. All dash four and all with well under 1000 hours on them.

R22 Blade Delamination
 

I think there is a very important point being missed here. There have been numerous accidents and incidents involving R22s and R44s. We have all heard other pilots relating "robbie blade delamination accident" stories. Up until now we had no definitive proof that these blades were in fact coming apart. The delamination was always conveniently explained away as a result of the accident rather than the cause of the accident. Now, due to this pilot's uncommon skill and a healthy helping of luck we have a machine parked on its skids with a 600 hr blade peeled apart like a filleted fish. CASA don't want to know about it. Has the FAA been notified? I wonder what their reaction would be when faced with grounding a significant portion of the revenue producing machines in the U.S.
Hey Frank, your machines are flying apart in flight. I know pilots who would rather risk losing their jobs than fly robbies. What is it going to take. These are not overflown mustering machines, they are always hangared, well maintained training and tourism machines. Next time it might be one of the low-time, wealthy private owners that CASA is scared of offending, then we'll see some action.
I'm not just having a whinge, let me know what I can do to help prevent another delamination accident. But let's do it now.

Do you have any more photos you can post?

i fly a 44 and have not encountered this yet. i say yet! how ever checking the blades every morning as is needed may not be sufficient. the paint on our blades is more eroaded on one than the other. still not back to the seem yet. they seem in top condition. and we fly over water on take off and landing.

i know flying in precip is not good on frankys blades especially in a salt enviroment. we wash our chopper every day for obvious reasons and im sure im going to encounter this at some stage.

sorry to crap on but here is my question

we operate an astro and delams seem to be happening on later models?
yes ?

correct me if im wrong.
does this indicate that frank has changed design and contruction methods that greatly that saftey is no some what comprimised.

BP

http://www.helicopterservice.com.au/...22%20delam.jpg

I'd be interested to know why there appears to be no signs of bonding in the highlighted areas.

I'd guess that the honeycomb in the blade has been distorted by the airflow on the way down (there is ample evidence that it was bonded, from the bonding marks left on the inside of the skin), but the blade spar and the skin both seem to show signs that the bonding has been failing for a while.

The bonding appears to be inconsistent.
In some places the adhesive has separated from either the skin or the structure cleanly. Looks as if it didn't take properly.
However if you look at the area just inboard of the tip it appears that the bonding held but the surface of the composite tore off. That looks like a solid bond to me with the joint destroyed by the force of the skin being peeled in the airflow.

Found this on RHC Website

http://www.robinsonheli.com/srvclib/...ding_31607.pdf

The operating enviroment and conditions, flying techniques have not changed.
Only the blades have changed. Obviously the old blades 40 thou skins were rigid enough to hold their shape even if not bonded correctly. The new blades have an 8 thou skin. Robinson's rushed production run to manufacture dash 4 blades probably came at a quality control sacrifice. Operators in erosive enviroments are going to have keep their blades painted (all eviroments), perhaps an outboard end repaint every 300 hours.
bigruss

I dont have access to Robinson service info so could someone tell me if Robinson call for any type of debonding checks prior to the blade surface finish being restored?

Thanks
ericferret