A solution to a Cof G problem on a Bristell NG5 is to install 5kg of ballast as for forward as possible.

There is a convenient place behind the gearbox on a 912iS.

Has anybody ever had to fit ballast, or have fitted ballast to the engine on a 912iS


  • Re: Installing ballast 912iS

    by » 5 weeks ago

    5kg is 11lbs!

    We have not seen anyone place this kind of weight behind the gearbox of a Rotax before and have no idea what kind of issues would come from it. Can the engine mount allow for that amount of additional weight?  This is something you would need to discuss with Bristell about 100%


  • Re: Installing ballast 912iS

    by » 4 weeks ago

    There is an issue with the Bristell W&B in the UK. The 912is is about 7kg heavier than the ULS and is less likely to have an issue.




  • Re: Installing ballast 912iS

    by » 4 weeks ago

    The engine is a 912iS. The aircraft is a taildragger. The LAA have moved the pilot CofG aft by 150mm. I.e greater than the range of Cof G. The obvious solution is to move the seat forward by 150mm. ( Yes there is room for an average body). But the LAA have refused.

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