OhD

I still have not heard anyone say they heard a control surface flutter during a fuselage failure event. It could be the fuselage itself hits some resonant frequency or just the constant pounding of the engine vibration. It sure looks like the crutch would have saved the one in the latest photos.
Has anyone heard of an electric powered Impact failing?

Jim O

SHAZAAM

THE IMPACT SHOWN IN THE PICTURES DID HAVE THE CRUTCH INSTALLED, THRER WAS NO PROBLEMS WITH THE RUDDER THAT I AM AWARE OF. THE AIRPLANRE ONLY HAD ABOUT 5 FLIGHTS. IT IS VERY DISSAPOINTING TO HAVE A PROBLEM THAT COMPOSITE ARF NOWS ABOUT AND THEY WILL NOT RESOLVE. I THINK IT WOULD BE EASY TO SOLVE IN THE MOLDS, AND NOT TO DEPEND ON THE PEOPLE THAT HAVE PURCHASED THE AIRPLANE TRY TO SOLVE BY CHANGING RUDDER ETC. COMPOSITE ARF NEED TO STEP UP!!!!!!

Derek.Koopowitz

I thought Buddy stated that the plane did not have a crutch or ladder installed in the fuse and that it had flown for a couple of hundred flights already.

mups53

My Feedback: (41)

Hate to barge in but I don't see anyone bringing up what I consider the most important issue here which is safety. If you have a plane disintegrating in the air there has to be a loss of control. I don't see how Composite Arf can ignore this issue. From what I have seen of these posts I wouldn't advise flying one of these potential hazards. I would also say that as an owner of one I would be afraid of the liability. It's just too risky to take a chance that could endanger others. Mike

BrianB

My Feedback: (2)

!QUOT!THE IMPACT SHOWN IN THE PICTURES DID HAVE THE CRUTCH INSTALLED!QUOT!


Shazaam, was it a crutch or just the rear former installed, I think if it had a crutch running up the length of the fuzz to the rear of the canopy it would not have broke where it did. If it did have a crutch I am starting to worry, I installed a crutch and so far so good. Its one of those planes that you should shove a body bag {glad trash bag} in just to have something to carry it home with. Oh well I'm flying mine till it decides it does not want to anymore, then I will just go buy the latest and greatest P.O.S.

SHAZAAM

THE PLANE IN THE PICTURES IS NOT BUDDYS, THE IMPACT IN THE PICS HAD THE CRUTCH INSTALLED PER COMPOSITE ARF. IT IS VERY DISAPPOINTING WHEN YOU ARE TRYING TO GET READY FOR THE SEASON, THE AIRPLANE IN THE PICS HAS BEEN REPLACED BY A BETTER AIRPLNE!!!!!

papaone

Hi
In response to Betelgeuze (post 23).
A few months ago, I hesitate to buy an Impact and finally I chose a Rhapsody of Modelltechnik.
I also bought the cocaine (It looks like the Impact) and I received it a few weeks ago.
The manufacture of these planes is much more advanced than the Impact :
Wing's tube, carbon tubes of the stab are fitted. It's very easy to make it, only somes hours. Alignment between wings and stab, incidences of wings and stab are perfected. Prices are similar (for white or blue or yellow color the cost is 999 euro). There are many designs painted in moulds (3 options : 50, 85, 165 Euro in relation with kind of design)
The plane fly straight ahead and there is no trim with the setup of origin of construction.
I know Mr Lorenz of Modelltecknik deliver Denmark. Link is :http://www.f3alorenz.de/
If you sent a mail (in english) Mr lorenz is very nice and anwers you quickly.
Below somes pictures of Cocaine.
Claude

50%plane

My Feedback: (5)

999 euro!! Thats almost $2000!!! I probably couldn't aford the cowl.

Malcolm H

$1294 actually!

Malcolm

50%plane

My Feedback: (5)

Isn't the exchange rate 2:1.

ini

Appr. 1.3:1 See e.g. www.oanda.com


ini

50%plane

My Feedback: (5)

Thanks Ini! I had read on other web sites that it was 2:1 against the dollar. This had then been confirmed by others that I know.

OhD

I look at the photos of the failed airplane (that is not Buddy's) and it looks like the left side of the fuselage failed in compression forward of the newly added bulkhead. In order for this to happen the crutch would have to fold up. Was this crutch made of foam or balsa? Are there any photos of the inside of tail end of the fuse?

Jim O

50%plane

My Feedback: (5)

I don't have one and will never get a composite, but the review in Model Aviation showed carbon.

Eggert

Hi Papaone

A couple o' years ago, i drove by Mr Lorenz in Germany and I saw the Rhapsody and actually decided to go for one of those. Then later I found out that there would be a substantial deliverytime and instead of waiting I went with an Alliance. Perhaps production capacity has increased. The Rhapsody and Cocaine is splendidly manufactured but still they cost 350 Euros more than the Impact. For the price difference I will gladly install a "ladder" and make a balsa build rudder weighing 40 grams.

But please remember to post your flying experience with the Cocaine it seems promising.

Best regards

Beetlejuice

David Gibbs

A couple of thoughts:

-- I don't know about Dauphin's, but for the compression style failure in 'toysejr' pictures above one aproach is to put in on a fuz jig to straighten it out and push the area near the failure back into shape, then use the dremel cut-off wheel to cut some 6 to 8" long, 1mm wide slots along the fuz (sorry for mixing units!!) at 8 to 10 places around the circumference and then epoxy in strips of 1mm x 3mm carbon section (the stuff that is used on shockflyers). Wipe off the excess epoxy and clean up with Metho as you go. I have seen this done on this type of construction it was very effective. It also works for foamies when you break their backs and need to put strength back in!!

-- For the 'toysejr' failure I follow Jim O's lead and would like to see any photos of how the internal crutch failed. From what I have seen, the rear former wasn't enough (and appeared to move the likely failure point forward a couple of inches), but I am bit baffled as to how this could happen with the crutch installed. I have spent quite a bit of time cutting and trying to bend/break bits of Depron in similar situations to get my own confidence that it is strong enough as a crutch, and have been impressed with its strength.

-- Buddy's failure sounds like it is different issue -- I have no details but my memory tells me I have heard of other examples of seams in this type of construction opening (not in Impacts, but other models using this type of construction). While this doesn't make it any less serious or frsutrating, it may not be related to the flutter discussion.

David

SHAZAAM

my thinking is we should not be fixing these airplanes for composite arf, they should be willing to step up to the plate no matter if the failure is a seam or the fuse bucking witch is what happened to the airplane in the photos above

50%plane

My Feedback: (5)

SHAZAAM They have no warrenty at all. I wonder why anyone would even buy them after reading this thread. If they came out with a good warrenty( which would put them out of business due to all the claims that they would get) they might sell more, but for now I think they have a crappy business run by crappy people producing crappy airplanes.

MikeEast

My Feedback: (3)

There are no pictures of Buddys airplane in this thread, the pics are of someone elses airplane.

I think that they are starting to replace some fuselages now anyway. After my trip to Pensacola last week I know of 2 fuselages that they have replaced. Regardless whatever they ship out they need to proactively back up its structural integrity "as shipped" 100% in every single case. Not just when they get sick of hearing the complaints or they start to look bad.

Eric.Henderson

A tip that might prevent failures for all of us, who had one before the failure started occuring.

The the fuselage skin is very thin. You can ***** a pin through it with ease. It also dents very easily. Once it dents, the skin can lose its integrity very easily. I have been working with these materials for quite some time now and I regard them like balsa sheeted foam wings. Once you mess up the skin you can get problems. You can strengthen the poly-U foam locally with thin CA and also a piece of .6 oz cloth and the CA. A big drop of CA on the inside of the dent will help.

I store and transport my skinned-polyurethene-foam-lined planes differently from my older FG fuselages. These planes are never put on my travel racks. The are rested on the floor of my vehicle. The center of the fuselage is supported by a 6" wide expanded-polystyrene carved foam block. This block has a 1/2" layer of carpet-soft-foam-underlayment as a bed for the fuselage bottom. The block is hot wire-carved/curved to match the fuselage shape and the wheels just touch the ground. This prevents local pressure points and also stops the wheels getting flat spots.

My in-house storage racks now have foam block blocks to also spread the load in a similar way to the travel-blocks.

I'd look for any denting in the area where the photos in this thread showed the failure. It is a location where a rack or stand could cause denting.

Not trying to create a panacea to the problem, but if we save one plane it was worth the typing.

Regards,

Eric.

oisf3a

I am about to flight test my new Impact. Testing a new plane is usually something to look forward to but with all the failure reports I am not so sure about this one. I've installed a depron board all the length of the fuse and also a former in the rear. The rudder is scratch built from balsa (50 g) and hinged the traditional way. The pull-pull cables are attached higher on the rudder to reduce torsional load on the rudder itself.

After all these mods I am still a bit worried and as a final measure I have added several strips of glass-reinforced tape on the OUTSIDE of the fuse. This tape is very strong, sticks well to the surface and will act as a rip-stopper in case the fuse shell should develop cracks.

The tape is not very visible against the white surface. However, it is a shame to make a brand new plane look repaired before its flown. ...

50%plane

My Feedback: (5)

My question to Composite ARF is: WHY SHOULD YOU HAVE TO DO THIS?

SHAZAAM

come on guys lets keep this alive, are there any other impact failures out there. The last I heard composite arf still is not willing to do anything to fix the problem with the airplane in the pics.

Magne

Nice looking plane, Oistein.
How did the test flights go?
Regards,
Magne

oisf3a

Hi Magne

The test flight went OK, at least no cracks in the fuse !! Have to adjust the right thrust and CG. It was too tail heavy for my liking, didn't have the 'locked in' feeling. I think I will fly my old Synergy in the first competitions and fine tune the Impact in between.