// 2.3 = -ln(0.1), i.e. x=2.3 is the 90% point we're defining
// The extra fudge factor is there because the N1 speed (which
// determines thrust) lags the N2 speed.
// 2.3 = -ln(0.1), i.e. x=2.3 is the 90% point we're defining
// The extra fudge factor is there because the N1 speed (which
// determines thrust) lags the N2 speed.