Added a Groovy oneliner of the same simulation (by the way, WTF with the BigDecimal stuff?? Its does't work as expected for very small number using Double's).
Added the calculation of the total distance travelled by the plane.

It seems to confirm the D=πR/2 / sinα formula (theory: 2.22144*R).
Added an assertion verifying the relation D=Rπ/2 / sinα.
Prevented the simulation to append the result to previous runs result files. It now clear the file before appending to it.