The inbound air carrier is required to file the ACAS data if no other eligible party elects to file. CBP is allowing parties other than the inbound air carrier to file because in some cases, these other parties will have access to accurate ACAS data sooner.  For effective targeting to occur prior to loading, it is essential that the most accurate ACAS data be filed at the earliest point possible in the supply chain.  This approach is consistent with parameters in the Trade Act of 2002 that require CBP to obtain data from the party most likely to have direct knowledge of the data and to balance the impact on the flow of commerce with the impact on cargo safety and security.