Section 45(4)(l) in The Air Corporations Act, 1953
(l)the aggregate cost of all licence fees paid by the company under clause (c) of subrule (1) of Rule 154 of the Indian Aircraft, 1937, in respect of the licences granted to it for the operation of any scheduled air transport services and held by it on the appointed date and which but for the provisions of section 19 would continue to remain valid plus a sum of Rs. 100 for each such licence; provided that the fees paid for each such licence shall be reduced by an amount which bears to such fees the same proportion as the period of the licence which shall have expired on the appointed date bears to the total period of the licence;