Engine RPM are about double what pilots of other “Jurassic-era” machines are used to, but despite spinning twice as fast, the Rotax is significantly quieter.
In the -JF the tachometer counts (reduction-gear reduced) propeller RPM,
which should allay any frightened quivering or consternation amongst the die-hard
vintage — read “conventional” — aircraft pilots.
www.tecnamaircraft.co.uk/p2002article.pdf
www.tecnamaircraft.co.uk/p2002article.pdf
The confusion on Tacho readings seems to be purely due to the difference with the certified versions. You guys must be wondering what planet the other is on....
Regards the discussion about worn tacho drives and prop changes, -
the prop and engine always spin at the same ratio regardless. Any tacho errors are like any instrument errors,... always lurking.