def _parse_flight_condition(mach_line):
    """reads a flight condition line"""
    mach = float(mach_line[0:10].strip())
    alt = float(mach_line[10:20].strip())
    pstag = float(mach_line[20:30].strip())
    tstag = float(mach_line[30:40].strip())
    igas = int(mach_line[40:41].strip())
    nalpha_beta = int(mach_line[41:43].strip())
    try:
        ideriv = int(mach_line[43].strip())
        dangle = float(mach_line[45:55].strip())
    except:
        raise
    assert igas in [0, 1], igas
    return mach, alt, pstag, tstag, igas, nalpha_beta, ideriv, dangle
