Composite Helicopters KC518 Adventourer [Archive]

krypton_john

7th May 2013, 00:05

Sounds like a prototype has been ditched in the sea. Sounds like the crew are all ok - I really hope so:

Helicopter crash at Mechanics Bay - Story - NZ News - 3 News (http://www.3news.co.nz/Helicopter-crash-at-Mechanics-Bay/tabid/423/articleID/296831/Default.aspx)

Helicopter Crashes Into Water In Auckland | Stuff.co.nz (http://www.stuff.co.nz/national/8641791/Helicopter-crashes-into-water-near-Auckland)

Bugger, I guess this wouldn't be the first prototype to come unstuck. I really hope that as indicated, the crew are ok and that the development continues.

Weather in Auckland today is beautiful - clear skies and light winds.

Peter3127

7th May 2013, 00:49

Sounds textbook. Almost good advertising in a way. :O

I hope it does not set their program back too far.

hillberg

7th May 2013, 01:21

No bellmouth or FOD screen, A June bug could of wrecked that engine,:{

mickjoebill

7th May 2013, 01:24

Pilot reported engine failure, semi controlled ditching into shallow water.
Witnessed by the other prototype.

I hope at least they can learn something positive from the excursion.

Saw it at the airshow recently, bloody marvellous.

In general terms can a carbon fibre frame recover from a soaking?

Best wishes to all the team

Mickjoebill

blakmax

7th May 2013, 01:46

MJB

Provided that the structure is not fractured it may* be OK. The biggest threat to laminated composites is from impact damage which causes delaminations between the plies. These can be tricky to spot because carbon fibre materials are linear elastic to failure, in other words they do not bend, they either break or spring back to their original position. Unfortunately the same is true for the layers over a delamination, so they are not visible. You need ultrasonic NDI or a tap hammer to find them.

The other problem is that depending on the resin type used, impcat damage can occur at quite low impact energy. Simple tool drop accidents can result in significant delaminations. Provided he didn't hit the water too hard it may be OK.

Blakmax

krypton_john

7th May 2013, 01:59

Updates coming through now - as MickJoeBill said - engine failure followed by what sounds like a textbook auto/ditching and water escape. Pilot and passenger not a a scratch. Wow.

Helicopter Crashes Into Water In Auckland | Stuff.co.nz (http://www.stuff.co.nz/national/8641791/Pair-unscathed-after-Auckland-helicopter-crash)

tartare

7th May 2013, 06:44

This TV3 story (http://www.3news.co.nz/VIDEO-Helicopter-crash-landing/tabid/309/articleID/296891/Default.aspx)has video of the autorotation.
Lot of smoke from the turbine - FOD, chip, oil...?

John Eacott

7th May 2013, 06:57

This TV3 story (http://www.3news.co.nz/VIDEO-Helicopter-crash-landing/tabid/309/articleID/296891/Default.aspx)has video of the autorotation.
Lot of smoke from the turbine - FOD, chip, oil...?

I think that you may be confusing the feathery downwash: no smoke that I can see.

Arrrj

7th May 2013, 08:02

I agree with comments, a well handled engine failure, and probably good advertising for the machine. Everyone got out and it handled the auto into the water pretty well.

Good on them. For those interested, the specs are pretty impressive. Similar to a 66 and way better than a 206.

Glad they are OK. The world needs motivated people like these guys.

Arrrj

PS - it was a photo flight, not testing, they have already flown over 200 hours in the type.

krypton_john

7th May 2013, 08:21

I think as he was autoing into the water he was heard to cry out

"Arrrrrrrrrrrrrj !!!!"

Is he a friend of yours? :-D

But seriously, how many hours flying to does one do to get such a machine to market? How many hours did Robinson put on their R66 prototypes before the first production machine was built?

I would have hoped it was thousands?

Arrrj

7th May 2013, 08:25

Krypton,

Funny !

I have no idea of hours of testing...I just know that they stated this in the news report. "not testing...photo flight" (or something like that).

I understand the 66 was extensively tested due to the changed rules in the USA. I do know that they got two of the highest hours pilots from other countries, to test fly the machine. The one from Aus, who I know, has 12,000 hours, and told me it was fantastic.

Yep, I am fan of the 66...but probably would be of the composite machine too !

Arrrrrrrrrrrrrj !

Savoia

7th May 2013, 11:33

BBC News - New Zealand helicopter ditches in Auckland harbour (http://www.bbc.co.uk/news/world-asia-pacific-22431549)

Don't worry, I'd never heard of a KC518 (http://www.compositehelicopter.com/) before either!

Never in Balance

7th May 2013, 11:37

http://www.pprune.org/rotorheads/462151-composite-helicopters-kc518-adventourer.html

Check here. :)

Gemini Twin

7th May 2013, 18:08

Just a comment, but considering how import this truly promising helicopter is to the company and NZ aviation, it seems a pity that they were forced to rely on a old "Zero hr TSO T63".

krypton_john

7th May 2013, 19:39

Well, that's one of the engine options, it is usually a reliable option, and it seems a good idea to test it out under the most difficult conditions possible.

But yeah, they're clearly not funded by someone's defense budget.

krypton_john

7th May 2013, 23:01

Helicopter recovered from sea bed this morning - picture here:
Helicopter salvaged after Auckland harbour crash - National News | TVNZ (http://tvnz.co.nz/national-news/helicopter-salvaged-after-auckland-harbour-crash-5431241)

Looks in decent shape apart from the rotors.

tartare

7th May 2013, 23:55

John - on second viewing, you appear to be right, my mistake.
Still - shows what happens when you have to rely on British engines :E
Shame they couldn't manufacture a domestic gas turbine as well!
Best of luck to the Composite Helicopter guys - agree with previous poster who said we need more people with that kind of vision and drive.
For a tiny nation, NZ punches well above it's mechanical engineering weight.
John Britten, Pacific Aerospace, Glen Martin...

cattletruck

8th May 2013, 00:41

Gear box, engine and even the rotors did not separate from the aircraft, I guess you cannot call it flimsy.

Even though the accident was a bit of bad luck, I'm sure they now have extra data to make the type even better than it already is.

tartare

8th May 2013, 04:23

Good point - given deliberate rollovers when auto-rotating an aluminium machine into water often end up with a spectacular departure of the main gear box and rotorhead - sometimes through the cabin:eek:
Does anyone know where they manufacture the carbon fibre components - I assume that Hi-Modulus (now bought out by Swiss company Gurit?) on the North Shore have helped them?

John Eacott

8th May 2013, 04:54

Still - shows what happens when you have to rely on British engines

I see the evil grin, but I thought the engine was the current derivative of the Allison C20?

I'd agree that the design team are due a lot of kudos and I'm looking forward to seeing it in production: especially at the current advertised price :ok:

RVDT

8th May 2013, 06:58

Rolls Royce by name GM Allison by nature!

First ran in 1959 and qualified in 1962.

Good info here (http://www.enginehistory.org/Convention/2009/Presentations/Model250Hx.pdf). 50 years young! Check out some of the derivatives especially the twin pack!

It seems that the good ideas have all been cherry picked which is OK until you try to do it commercially.

Remember it took 15 years for the G2 to get a Type Certificate!

This aircraft is a prototype amateur built aircraft. A long way from a commercial version but a good place to start? Who knows and the best of luck to them.

as350nut

8th May 2013, 07:34

Thanks for that link, on the Allison 250 series, really interesting. I hope these guys keep going with the composite concept, I think they will benefit from this experience(given some time) They have; shown it autos beautifully; it doesn't kill you in a water landing (try that with a robi ) ; it stayed pretty much in tact, so great strength in the airframe. Its a shame they can't put together blades, mrgb,trgb, all from other known main stream manufacturers so as to cut down the certification times. Seems counterproductive for any new type to have to prove every bit of there new aircraft. My wish would be for say MD500 4 blade hub, new burp blades for the 500 series, trgb of anything that's big enough and been around for awhile. Put in the new RR300 engine and lets go flying. Of course, that's a daydream:(

topendtorque

8th May 2013, 08:42

Can your 500 xmon be rated up to 450hp? check again the mt wt on this gadget, you will see where its real strength is. leaves the others for dead.

Scissorlink

8th May 2013, 08:52

Those blades have some inertia !

hillberg

8th May 2013, 23:35

Looking at the video , Might of had a reduction in power as the rotor wash was down wind during the landing, Not a complete loss of power but a power failure none the less.:{

Peter3127

9th May 2013, 07:47

Word from the company itself is that the machine is completely intact despite a tail boom strike when hitting the water. A pretty impressive performance and provides a wealth of data from an (albeit inadvertent) test that most manufacturers would not line up for. :)

John Eacott

10th May 2013, 22:03

cFHEvRGDVi8

Colibri49

10th May 2013, 22:57

"The reason we were over the water is because we are still in our flight evaluation phase, if you like." ??? Does not compute !

Extremely expensive prototype under development and yet it's okay to risk losing it in the salty sea. The engine didn't fail completely and it could almost certainly have been put down somewhere upright and on dry land with absolutely no ensuing damage, had it been close to the shore.

The carbon fibre airframe won't be affected by salt water immersion, but most of the alloy components will probably need replacing. Even short sea water exposure can initiate surface micro-pitting to bare metal.

Were lifejackets being worn by the occupants? What was the assigned crew function of the young woman on a development test flight? Would insurance have covered her in the event of a tragedy?

All credit to the pilot for executing a successful restricted power landing, but I suspect that the investors are going to want answers to the above questions. Watch this space.

Vertical Freedom

11th May 2013, 01:17

Great job by the Pilot, well done :cool: welcome to the Club :{ Successful Autorotative landing following engine failure (swimming away) Club ;)

Land Happy Always :ok:

RVDT

11th May 2013, 05:22

"The reason we were over the water is because we are still in our flight evaluation phase, if you like." ??? Does not compute !

It does if you cannot fly over a built up area by being in experimental category.

The carbon fibre airframe won't be affected by salt water immersion,

True, but that is the least of your worries. How do you NDT carbon structures after damage from impact, fiber breakage, thermal exposure or applied stress? Not simple I can assure you.

mickjoebill

11th May 2013, 09:09

What an age in which we live when a day after an incident the manufacturer releases onboard images complete with a description of the event.

Good stuff, better to get your own message out which then becomes the content of social media, rather than have ill informed opinion run amuck.

Mickjoebill

Colibri49

11th May 2013, 09:15

"It does if you cannot fly over a built up area by being in experimental category."

This had occurred to me, but why fly over either a built-up area or the sea while performing development test flights? From Google Earth there would seem to be no shortage of open land between the concentrations of buildings.

The answer to the question about lifejackets should clarify whether the test flying programme was intentionally being performed over water because of unavoidable built-up areas.

Again, it would be interesting to know whether the young woman was an assigned crew member and whether she was covered by insurance.

NDT carbon structures would apply after heavy impact with land or water and doesn't address the question of whether the aircraft ought to have been so far out from the shore.

krypton_john

11th May 2013, 10:16

Colibri, due to NZ accident compensation legislation, the insurance question isn't really applicable.

It seems to me unlikely they would want to fly that fuselage again though. Given the millions they have put into this project, I expect a couple of hundred k in the fuselage is not worth risking flight. It would make a good gate guardian now.

Colibri49

11th May 2013, 11:39

Quote from tartare: "For a tiny nation, NZ punches well above it's mechanical engineering weight."

Let me make it clear that I totally agree with this statement. That replica of a Mosquito WWII bomber is awesome. Furthermore the world's best electric VP propeller for light aircraft comes from Airmaster in NZ and that isn't only my opinion.

I have family in the Auckland area and it seems to me that NZ has the greatest per capita enthusiasm on the planet for aviation in all its forms.

So what's my gripe? Carbon fibre and lightning. For my recreation I fly an aircraft built of glass fibre composite and I'm very aware of how totally a lightning strike could shatter/pulverise the airframe.

I believe that the same applies to carbon fibre composite structures, which is why components of airliners built by Airbus and Boeing have metal mesh or perhaps other metalised layers embedded in the carbon fibre to dissipate static electricity and lightning strikes.

Furthermore there is the phenomenon of "helicopter triggered lightning" which is being promulgated by the UK Met Office and updated frequently throughout each day for North Sea helicopter operators to plan with. It takes account of a temperature band around the zero degree isotherm and other factors. No flight is allowed in red areas and amber areas are treated with caution.

From what little I understand of this fairly new science, helicopters with composite blades are far more likely to trigger a lightning strike than are aeroplanes. Perhaps due to air friction over the spinning blades which might excite more static electricity than airframe components.

Even if the KC518 doesn't have composite blades, I hope that they're doing something to dissipate static electricity in the fuselage. Failing that, they should be making clear on a prominent page in the flight manual the importance of avoiding potential lightning conditions.

blakmax

11th May 2013, 22:33

C49

I think that the composite lightning strike issue is overplayed and results from incorrect definition of testing requirements. If you test a composite panel in isolation with simulated lightning strikes, then yes there is damage and yes if you add a mesh the problem is mitigated. However many years ago I saw some test results from a French manufacturer of military jets where they tried testing composite panels but had them mounted in a metallic frame, in a similar manner to how a composite panel is bolted to an airframe, and they could not get the lightning to hit the composite area. It would always hit the metallic support frame. They also tried using a metallic strip around the panel which was grounded to the sub-frame using fasteners and had the same effect.

I have never liked the mesh approach because it is damned near impossible to implement a repair to the structure and then restore the mesh conductivity.

Regards

Blakmax

mickjoebill

11th May 2013, 23:21

Do they usually fly with a few cameras fixed to the airframe?

mickjoebill

1969shelby

12th May 2013, 04:02

Has anyone begun doing experiements with bamboo? I feel dumb for asking this question, because it seems almost laughable, but I have read reports about the superior strength that it has over steel and I can't help but be reminded of the wooden blades of the Bell 47. Just curious.

RVDT

12th May 2013, 07:17

C49,

NZ is still a free country. The owner was flying his own helicopter and within the bounds of the regulations he can do whatever he wants with it.

Placarded as follows:

WARNING – EXPERIMENTAL
THIS AIRCRAFT DOES NOT MEET THE
NEW ZEALAND AIRWORTHINESS
REQUIREMENTS FOR STANDARD OR
RESTRICTED CATEGORY AIRCRAFT.
PASSENGERS FLY IN THIS AIRCRAFT
AT THEIR OWN RISK

In accordance with AC21-3 - Civil Aviation Authority of New Zealand (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDkQFjAB&url=http%3A%2F%2Fwww.caa.govt.nz%2FAdvisory_Circulars%2FAC21 _3_Rev2.pdf&ei=lz-PUaDGFsjBtAak34CoDA&usg=AFQjCNFN6zTRlxO7bHdazEil9pnfvPVmwA&sig2=A38Vh_4zTOk1lLcw7L3LlA&bvm=bv.46340616,d.Yms)

RVDT

12th May 2013, 07:23

Blakmax,

I have never liked the mesh approach because it is damned near impossible to implement a repair to the structure and then restore the mesh conductivity.

If you have the chance take a look at an EC135 tail.

Numerous issues with copper mesh over carbon interfaced with alloy components - nightmare! In some places bare alloy onto bare copper! WTF? :ugh:

Carbon fibre boats are also fun if you forget that carbon is a very good conductor on its own.

cattletruck

12th May 2013, 07:37

just thinking out aloud regarding composite structures and lightning strikes, couldn't a metal film mesh decal or simply lines of conductive metallic paint be applied to the outside of the composite structure and then painted over with normal livery to achieve the desired protective function?

The church I used to walk through to take a shortcut to work used to only have a very thin earthing wire that ran to the top of the steeple to take the load when lightning striked.

RVDT

12th May 2013, 07:53

CT,

Basically what happens already. Dexmet (http://www.dexmet.com/Aircraft-Lightning-Strike-Protection.html) is one manufacturer.

cattletruck

12th May 2013, 08:16

Thanks RVDT, so it's fair to say that there is already a proven and simple solution for protecting composite structures from lightning strikes. Perhaps it's application is not widely known by manufacturers of lightweight composite aircraft as I cannot imagine this to be a prohibitively expensive item to implement.

blakmax

12th May 2013, 10:11

RVDT

I haven't seen an EC135 tail but by your description maybe I should.

Catlletruck (love the tag!) If you calculate the weight of the decal and adhesive, maybe that approach is about the same as embedding a copper mesh in the composite resin. I still think the issue is being determined by limitations in defining the test parameters.

Let me give you an analogy. There was a fellow traveling on a bus in an Astralian city and he was tearing a newspaper into tiny pieces and throwing them out of the bus. The conductor said, "I noticed you throwing paper out the window. Stop that, it is littering!" To which the fellow replied "But that is to scare away the elephants". The conductor says "But there are no elephants at all in Australia". The reply? "Effective isn't it?"

If you set out to measure the results of an ill-defined test, you get the outcome you want.

If you want to discuss the stupid justification for removing cladding from aluminium alloy surfaces before bonding, I would be happy to oblige. Yet anther example of ill-defined test parameters, and this causes heaps of needless work for repair technicians and increases the risk of corrosion dramatically.

As far as inspecting the structure after immersion for impact damage this can be easily achieved by ultrasonic inspection by A, B or C scan methods. The warning I would offer my NZ friends is that if damage is detected, please do NOT under any circumstances use injection "repairs". You may in fact REDUCE the residual strength of the laminate.

Regards

Blakmax

topendtorque

12th May 2013, 11:24

The church I used to walk through to take a shortcut to work used to only have a very thin earthing wire that ran to the top of the steeple to take the load when lightning striked.

Many so called lightning conductors are light especially if they feed to a central point from an underground spider web of copper wire.(all NDB and DME towers were set up like that)

They thus "milk" the charge from the ground and disperse it in orderly fashion towards the hand of God without waiting for the fist of Thor to smite them a mighty blow.

Often you will see a strong blue stream of what looks like light heading skywards from the sharp high point on the building at the end of the copper wire as a storm approaches.
tet.

pilot and apprentice

12th May 2013, 20:55

blackmaxC49

I think that the composite lightning strike issue is overplayed and results from incorrect definition of testing requirements. If you test a composite panel in isolation with simulated lightning strikes, then yes there is damage and yes if you add a mesh the problem is mitigated. However many years ago I saw some test results from a French manufacturer of military jets where they tried testing composite panels but had them mounted in a metallic frame, in a similar manner to how a composite panel is bolted to an airframe, and they could not get the lightning to hit the composite area. It would always hit the metallic support frame. They also tried using a metallic strip around the panel which was grounded to the sub-frame using fasteners and had the same effect.

I have never liked the mesh approach because it is damned near impossible to implement a repair to the structure and then restore the mesh conductivity.

Regards

Blakmax

I think you proved the point you were trying to make, but I'd disagree with the result. That airframe manufacturer should have been testing the panels as they would be installed. I'd be very surprised if in any real-life application the metal frame would be exposed like in the test.

The little first-hand exposure I have had to this is from friends who were flying the Emb145. They had a lightning strike in a composite wingtip in cruise and the result could best be described as a broomstick of fibers. The composite did take the hit.

The repairability of the conductivity isn't something I had thought about enough. Thanks.

blakmax

13th May 2013, 12:12

P'n'A

You do make a valid point, but that is a design issue. As long as manufacturers make composite panels which fasten onto flat airframe members, the substructure will not be exposed to lightning contact. However, the fasteners certainly will and it is my experience that even on metal structures lightning access points often are fasteners attached to sub-structure, unless there is a very large area of non-connected structure.

With chem-milling techniques it would be easy to leave a small ridge of metal at the joint of fuselage panels such that lightning would preferentially attach there.

In the "toothbrush" failure mode you describein the wing-tip example there is probably no metal at all, and for such structures maybe the addition of a lightning tracking path metallic option (even the decal suggestion mentioned before) would be a better option than just letting nature take its course with the consequent toothbrush result. Even something like a metallic leading edge abrasion strip would do that task. Heaven forbid, maybe the mesh option would be appropriate but someone please explain how you would repair the region? At least with a conductive decal, you could rip it off and replace it. You may need to do a local repair for the strike zone but at least the restoration of lightning protection would be definitively better.

Regards

Blakmax.

HeliHenri

13th May 2013, 12:38

.
There are not a lot of new projects like this one in the heli world so after those bad times, I wish to offer my encouragements to the team ! :ok:
.

Composite Helicopter

12th Nov 2013, 06:12

Thanks to all who have made comment and asked questions about of new helicopter. Isn't it great!

We are new to pprune forums. A link was provided to us suggesting that as the manufacturer we may like to participate. More than happy to join in the banter and to answer your questions. Cheers Peter

Carel Janse van Rens

13th Nov 2013, 15:27

Hi there Peter, I am very exited about the KC518 and would love to be your official agent in South Afica. Despite the perfect autorotation into the harbour it provided crucial data especially when the main rotor blades slamed into the fuselage. There is one question I would love to be answered and that is if KC518 is fired upon from underneath with an AK47, will the bullet penetrate the fuselage from a hight of about 500 ft ?

Ian Corrigible

1st May 2014, 14:50

This month's Rotor & Wing (www.aviationtoday.com/rw) provides an update on the KC518 project. Excerpts:

Despite an emergency autorotation and ditching of its KC518 Adventourer into Auckland Harbor New Zealand in May last year, an incident caused by a deterioration of the aft isolation dampers, founder and director of Composite Helicopters Peter Maloney told Rotor & Wing that aircraft No. 3 is now in the test phase while aircraft No. 4 is currently being assembled. (The second KC518 airframe was built with the express purpose of being used as an exhibit at airshows and aviation gatherings around the world.)

The KC518 kit will come with 20 major components including airframe, cabin floor, internal beams and bulkheads. There are around 22 secondary components that comprise carbon fiber doors and bulk hatches.

According to the company there are numerous benefits to this type of kit helicopter: the manufacturing process is quick and the assembly is straightforward and sequential. The airframe itself is light, the holding fixtures are easily set up within the fuselage and there are no bolted joints. The basic price for the initial kit is $335,000 although a fully completed helicopter will come to just under $400,000.

The prototype KC 001 was fitted with aluminum MRBs using an 8-inch chord...however Maloney notes the design has always included on-condition carbon fiber main rotor blades with a 9.5- inch chord. "Ray Prouty, a recognized helicopter main rotor expert, recommended the choice of airfoil used for the MRBs. Along with the development of the new carbon-fiber MRBs, we are expecting a significant increase in performance. While this is not necessary for the entry-level KC helicopter, it is an important design factor with future higher-powered derivatives. These new carbon-fiber MRB’s are designed for a gross weight of 4000lbs and MCP of 450 shp.”

From the basic design of the original KC518, the plan moving forward will be to evolve new helicopters with an increased seating capacity and greater performance. However, the immediate need is to obtain FAA certification, which should take a further three years to complete.

I/C

Rotor Work

9th Nov 2014, 02:34

Fly Safe
R W
http://media.nzherald.co.nz/webcontent/image/jpg/201445/SCCZEN_081114HOSSPLCHOPPER4_620x310.jpg

From New Zealand Herald

Helicopter crash north of Auckland - National - NZ Herald News (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11355406)

Two people have been injured following a helicopter crash in Rodney, north of Auckland.
Police say the chopper crashed into farmland at Duck Creek Road in Stillwater.
Westpac Rescue Helicopter has assessed the injuries of the Pilot and sole passenger, one of whom have been taken to North Shore Hospital with moderate injuries.
The other has been treated at the scene.
The cause of the crash is unknown.
Police have secured the crash site pending an investigation from the Civil Aviation Authority.

SuperF

9th Nov 2014, 07:43

Have they moved into the crash test phase?

Good to see they all survived. Looks like it is reasonably solid, even sitting on its side.

tartare

9th Nov 2014, 23:31

Not having a good run.
Lucky pilot survives his second crash - National - NZ Herald News (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11355587&ref=rss)
Dramatic shot of the chopper in the background too.

skadi

6th Jan 2015, 14:05

A broken scissorlink was the cause of the second crash:

Impressive video of this mishap with very lucky outcome:

Flight testing incident footage demonstrates strength of new composite helicopter on Vimeo

skadi

9Aplus

6th Jan 2015, 14:34

Congrats on C H approach to safety. Good move :ok:

army_av8r

7th Jan 2015, 02:18

Very good work to the crew, what an interesting video! You can clearly watch the shift in phase lag when the drive link fails. The forward cyclic that was being used for forward flight becomes a left cyclic input when that link breaks and the phase angle changes. I'm curious what effect the collective had throughout the forced landing. Did changing collective setting compress the pitch change links and cause an even greater change in phase angle as the PCL's lagged behind even further. Very interesting to see those results. Good work guys!

RVDT

7th Jan 2015, 06:45

Pitch links and swashplate.

An area where even some of the most experienced manufacturers and designers have got it wrong in the past.

Look at every prototype model in recent times and look at the amount of strain gauge work that is done in this area.

I would not be surprised if this was not just a simple component failure. Very complex stuff going on here. Possibly empirical info is insufficient.

This is a Special Category amateur built helicopter and therefore you only have to prove so much in the design.

John Eacott

7th Jan 2015, 07:25

Top job by the drivers :ok:

But playing devil's advocate, would there not be a good case for wearing parachutes when test flying new helicopters with such a deviation from more traditional construction techniques?

Excellent solution to install duplicate scissor links from now on.

tartare

7th Jan 2015, 07:48

That is one scary video.

RVDT

7th Jan 2015, 10:22

But playing devil's advocate, would there not be a good case for wearing parachutes
when test flying new helicopters with such a deviation from more traditional construction techniques? :confused:

Which bit deviates? The fuselage is a "one piece" carbon monocoque which sounds nice but has its limits.
i.e. you damage the tail and you have just damaged the whole fuselage.

The mechanicals are nothing special at all and probably as technically brilliant as a H300.

Parachute - you would need to be at least clear from the thing to deploy at the minimum of ~ 700'.
In this case I doubt that the thing would have remained stable enough after you unstrap, open door etc etc
and hoping that it is the right way up - good luck with that one.

Don't lose sight of the fact that this is an aircraft with a Special Category—Amateur-Built Aircraft Airworthiness Certificate.