Balsa/Conticell (Wing Core)

[Harald Gramer]

Hi,

I became a member of this fine forum because I am interested in buying maybe an ASW15b. ("Maybe" - because I am 188cm/ 6ft 2inches tall and I have never sat in one.)

One thing I am very curious about is the wing core: As far as I know all ASW15(b)s with serialnumbers up to 15356 have balsa as wing core. Later models use a foam called "Conticell".

What are the pros/cons of these two different cores? Does it make a difference in weight/ stability/ surface waviness (and in this regard: performance)/ maintenance? Have there occured problems with the balsa in the wingcore? (I have heard about the problems with fungus in the spar)


Is the price of a Balsa-core-wing ASW15 the same of a foam-core-wing ASW15 if anything else is comparable?

Kind regards,

Harald

[Joshy]

Hi,

flying and handlig is the same.
Conticell is better to work with and more time resistent.
A conticell 15 is about 10-20 kg heavier than a balsa one.
The fungi problem rests with all 15.
Because this problem is not a problem with the shell filling.
It was a problem with the spar filling.
An the spar filling is in all 15 balsa.
The funghi destroyed the spar of one 15.
This 15 stood a long time outside with wind and wether.
Water could rinse inside and enabled funghis to work.

A 15 which had rest normally in a hangar, in sunny dry states outside or in the trailer will not have this problem.
During fleet control of all 15 there were only 4 other with funghis.
All 15 got a anti funghi chemical spread inside the wings.
No further findings thereafter.

- no diffrence in price
- no diffrence in surface
- no diffrence in performance

Only diffrence in wing weight.
balsa: wings 62- 68 kg.
conticell: wings 70-75 kg.

Only as hind:
Many of the older gliders have balsa wings.
But only the 15 had the bad luck to get the funghi findings.
And oly because ther was a in flight structural desaster.
I think there will be other glider from other types which woud have findings if there would be a fleet control.
But no reference, no search for.

Best Regards,

Joshy

[Harald Gramer]

Hi Josy,

thanks for your reply - that´s good news because that makes it more likely for those who search 15s to find a good one - as they are all good.

Best regards,

Harald

P.S.: Not that I want to split hairs (can one say that in English???) but if Balsa-core-wings are lighter than Conticell-wings then the response to aileron input shoult be a little bit faster due to less mass on the same lever (sorry but I don´t know the word for "Massenträgheit" in English). And it also should be easier to feel on which side the lift is better when entering a thermal. But this happens most likely only in theory.

[inhopeoff]

Please will be sure, that the first AD about the inspection of "Balsa" will be performed with one of the official reports.
The probleme is not the "Balsa", it will be the  first infection of fungal. If it is locked by chemical liquid I have never found any problems during anual inspections later after desinfection.

[Joshy]

Hi Harald,

I tell you what.

Die Querruder sind bei dem Flieger sowas von wirksam.
So wie alle Ruder.
Auf gut deutsch:

Dat is völlich wurscht!

Gruß,

Joshy