Personally I think that a major contributer to the delam, is due to the sharp edges on the gear door cut outs. It is clear that the failure propagated from this area. My opinion is that the panel flutters slightly between the gear door cut out, and the bonded area behind. Glass fiber is a brittle material, and this is a typical case of a fatigue fracture failure. To prevent this I say cut the door opening as round and blended as possible, as per instructions. Never use sharp edged cutout on glass fiber, in fact any material, if it will be subjected to cyclic loads.
Pressurization is present in this situation, and the use of gear bay compartments would be a good idea. Cutting holes in the rear fuzz, will not in my opinion make much difference, apart from inducing a flow, and hence upsetting the airflow.

I would just like to comment on the construction of the hotspot, and say that in my opinion I think it is not sufficient for its purpose, and am surprised that there are not more failures. The hotspot is a great model, I have one, but due to pore design and construction of the fuzz I had to redesign the internal structure to satisfy myself, which inturn meant that the model talk a lot longer to make.

i own also a kangaroo from graupner

1 if you buy the set , all the dimensions they say to fit the gear are off even with 5 mm
how to fix it? they state: put a large light behind it end check
if it is correct

2 landing gear valves the manual: it is better to replace the maual valves with electronic one,s ( a well i feel much better now knowing i spend 300 euro,s on a gear wich graupner says replace the valves with electronic ones that cost a 100 bucks a piece)

2a: landing gear in general NOTHING FITTED!!!
all had to be fixed to make it fit and another 3 hours spend
on making it run

3 structual : a well it seems you have to double check their work
because on sopme place it does come loose since the covering is very thin , i suspect i will have the same bang if not fixed before any flight

5 : the servo brackets: very poorly made of some soft wood
even if you would use 10 kg,d servos you would brake them in half i am shure

6 canopy mounting: a well..... i would not fly with their solution

7 turbine mounting ( yes the washers why why why)
i cant see it is it me? why the hell would i need washers ?looks very poorly and shure looks anything then proffesional build
why did they not from the start raised it , even then if you set it up and measure it , its not even center made

8 paintjob: TERIBBLE not even sprayed but VERY thin printed
you clean the kangaroo you will loose the paintjob after ten times

8 alll in all ?? i would not suggest to get the kangaroo of graupner
but buy something else from a smaller manufacturer , since they still care about the finisching touch


anyway looks good , but i would never buy anything turbine related from them again...

reg Sandor

I though Fiber Classics made the Kangaroo and Graupner mad the Hot Spot???

At least that was it said on my Kangaroo from Plans Plus.

no graupner also has the kangaroo now , but i wont suggest it to anyone , however the price 750 euro,s (aprox 740 usd)
is good but after the changes you will have spend more......