19 CFR § 162.5
Search of arriving vehicles and aircraft
July 16, 2020
A customs officer may stop any vehicle and board any aircraft arriving in the United States from a foreign country for the purpose of examining the manifest and other documents and papers and examining, inspecting, and searching the vehicle or aircraft.
[T.D. 72-211, 37 FR 16488, Aug. 15, 1972, as amended by T.D. 90-34, 55 FR 17597, Apr. 26, 1990]