A method of calculating NLTE models of a plan-parallel solar flare atmosphere with stationary plasma flows is presented. To solve the radiative trans- fer equation, equations of statistical equilibrium (ESE) and the stationary momentum equation, we use the mul- tilevel approximate lambda iteration (MALI) approach. The numerical code is based on the method recently de- veloped by Rybicky & Hummer (1991, 1992) and allows to take into account macroscopic velocity elds in observer's frame formulation. The preconditioned ESE, constructed by this method, are nally linearized with respect to level populations and electron densities to treat the the hydro- gen ionization balance. The numerical code based on this method is used to compute a grid of NLTE flare models with various velocity elds in order to show the influence of the velocity elds on the H-line asymmetries. The analysis of the results lead to conclusions that would improve interpretations of flare line asymmetries: 1) The velocities aect the level populations, 2) The type of asymmetry depends on the changes in the optical depth scales and on the run of the source function in the atmo- sphere. 3) A monotonous velocity aects only one wing of the line prole. 4) To get the velocity eld from an observed prole the bisector method should be modied.