Unless suspended or revoked, a safety permit (other than a temporary safety permit) is effective for two years, except that:
(a) A safety permit will be subject to revocation if a motor carrier fails to submit a renewal application (Form MCSA-1) in accordance with the schedule set forth for filing Form MCSA-1 in part 390, subpart E, of this subchapter; and
(b) An existing safety permit will remain in effect pending FMCSA's processing of an application for renewal if a motor carrier submits the required application (Form MCSA-1) in accordance with the schedule set forth in part 390, subpart E, of this subchapter.