BASAs between the FAA and foreign civil aviation authorities allow approved parts manufactured under a foreign authority's oversight to be accepted for installation on US-registered aircraft without full re-certification. Importers must confirm that the specific part and manufacturer are covered under the applicable BASA and that FAA Form 8130-3 or equivalent documentation accompanies the shipment.

CBP classifies parts of aircraft under HTS Chapter 88 when they are identifiable as parts suitable for use solely or principally with aircraft. However, articles that could serve multiple end uses — such as certain fasteners, hydraulic fittings, or electronic assemblies — may be classified in their own material or functional chapter rather than as aircraft parts, making a principal-use analysis essential for accurate entry.