Guaranteed that a properly filled/sealed/sanded/painted BNC-55AO weighs more than a PNC-55AO.
You will not have any stability issues with the balsa cone.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !