Such pilot against whom such charges have been filed, upon depositing with the secretary of said commission an amount sufficient to cover the costs and expenses of serving such subpoenas, together with the mileage of such witnesses and an amount sufficient to cover at least three days' attendance of such witnesses, may require the secretary of said commission to issue subpoenas for witnesses in his behalf in the name of said commission, such subpoenas to be issued and served as in the case of subpoenas issued by the direction of the commission, and for failure of witnesses to attend upon being served with such subpoenas, the same penalty shall be imposed and collected as provided in Section 33-4-42.