Brian,


Not exactly a typo...

The 12x6 prop will be spinning faster and will output more HP than the 13x6.
And since speed, thrust and HP are related (HP is a multiplication of thrust and speed, stated in the correct units), the faster spinning 12x6 prop will make more thrust at higher flight speed, in turn enabling an even higher flight speed, until the equation becomes one <GGG>.

In static conditions and lower flight speeds, the larger diameter prop will have more thrust, because of its lower disk-loading and thus higher efficiency.

A 12x6 is not the wrong prop. It is just that in the typical flight profile of the Senior Telemaster, higher static and low-speed thrust levels are more important than high-speed thrust; thus making the 13x6 a more appropriate prop.