19 CFR § 122.163 - Transit air cargo traveling to U.S. ports.
(a) Application. If transit air cargo is traveling from the port of arrival to another U.S. port under § 122.119, a liability shall be assessed, as set out in § 18.8 of this chapter if there has been:
(1) Shortage in delivery;
(2) Irregular delivery; or
(b) Liabilities assessed. The liabilities assessed under this section are imposed as liquidated damages under a carrier's bond.
(c) Value of merchandise. The port director shall determine the value of merchandise for assessment purposes based on the following factors:
(1) Any data or documents available to the airline which presented a receipt for the transit air cargo, and available to the importing airline relating to the description and value of the cargo; and
(2) Other information available to the port director relating to the same or similar merchandise. If the data or documents required by this section are not submitted within 90 days of the date requested, the port director shall determine value on the basis of other available information. The transit air cargo manifest does not reflect value.