Sec. 2-5 Revenue and accounting practices.

(a) Revenue accounting practices shall conform to the provisions of account 2160, Air Traffic Liability. (b) Each route air carrier shall physically verify the reliability of its passenger revenue accounting practice at least once each accounting year. (c) For those carriers who use the yield or average-fare method to determine earned revenue, the analysis supporting the verification shall include: (1) The cutoff date for the liability to be verified; such cutoff date shall be at the end of a calendar month. (2) The number of months after the cutoff date during which documents were examined to verify the liability; the number of months after the cutoff date during which documents are examined shall not exceed the maximums set forth below: (3) The nature of the documents which were examined for purposes of the verification. (4) The totals for each of the various types of documents examined, on actual or sampling basis. (5) A description of the sampling technique and conversion to totals, if sampling was employed. (6) The amount and basis for all estimates employed in the verification. (7) The amount of resulting adjustments and the quarter in which such adjustments were, or are to be, made in the accounts. (d) For those carriers who use the sales-lift match method to determine earned revenue, the analysis supporting the physical inventory verification shall include: (1) The cutoff date for the liability to be verified; such cutoff date shall be at the end of a calendar month. (2) A trial balance as of the cutoff date of all subaccounts supporting the Air Traffic Liability control account; the subsidiary trial balance must agree with the Air Traffic Liability control account or a reconciliation statement furnished. (3) A statement to the effect that a sales listing of the value of all unmatched auditor coupons has been compiled and compared to the general ledger control figure; the statement required by this subparagraph shall indicate whether or not the value of the unmatched coupons is in agreement with the general ledger. If the sales listing is not in agreement with the Air Traffic Liability control account, the amount of such difference shall be shown on such statement.