  We study the first passage time (FPT) problem for biased continuous time
random walks. Using the recently formulated framework of fractional
Fokker-Planck equations, we obtain the Laplace transform of the FPT density
function when the bias is constant. When the bias depends linearly on the
position, the full FPT density function is derived in terms of Hermite
polynomials and generalized Mittag-Leffler functions.
