14 CFR § 19-8.9 - Control of sample selection and data recording.
Sample accuracy and reliability. To maximize the accuracy and reliability of the sample selection and data recording, each carrier is to:
(a) Develop a written statement describing the procedures it will employ in examining and selecting reportable flight coupons and in recording, summarizing, editing, and testing the Survey data;
(b) Submit any proposed changes in the procedures specified in paragraph (a) of this section to the Department's Office of Airline Information, prior to implementation of such changes;
(c) Establish continuous quantity controls on the flow of all lifted flight coupons through the carrier's accounting processing to determine the total number of coupons handled, and the number of reportable coupons selected. Tests are to be made continuously to assure that all reportable coupons are being selected and the data recorded. Such tests should be completed while the “lifted” flight coupons (representing earned passenger revenues for flight segments operated) remain in the possession of the carrier. Establish such other internal control procedures as are necessary for supervising and monitoring the accuracy of the recording of data from reportable flight coupons.