def METHOD_NAME(self, index):
    """
    Retrieves the airflow direction of a FAN defined
            by 1-based index <index>
    :param index: An integer, 1-based index of the FAN of which to query status
    :return: string, denoting FAN airflow direction
    Note:
        What Mellanox calls forward: 
        Air flows from fans side to QSFP side, for example: MSN2700-CS2F
        which means intake in community
        What Mellanox calls reverse:
        Air flow from QSFP side to fans side, for example: MSN2700-CS2R
        which means exhaust in community
        According to hw-mgmt:
            1 stands for forward, in other words intake
            0 stands for reverse, in other words exhaust
    """
    if not self.fan_direction:
        return self.FAN_DIRECTION_NOT_APPLICABLE
    if index > self.num_of_fan:
        raise RuntimeError(
            "index ({}) shouldn't be greater than number of fans ({})".format(index, self.num_of_fan))
    drawer_index = self._convert_fan_index_to_drawer_index(index)
    fan_dir_bits = self._read_file(self.fan_direction)
    fan_mask = 1 << drawer_index - 1
    if fan_dir_bits & fan_mask:
        return self.FAN_DIRECTION_INTAKE
    else:
        return self.FAN_DIRECTION_EXHAUST