19 CFR § 122.62 - Aircraft not otherwise required to clear.
(a) Bureau of the Census. Under Bureau of the Census Regulations (15 CFR part 30), aircraft not required to clear by § 122.61 shall obtain permission to depart if carrying merchandise from the U.S. to Puerto Rico or from Puerto Rico to the U.S.
(b) Bureau of Industry and Security. Aircraft leaving the U.S. for a foreign area must be cleared by Customs if a validated license from the Bureau of Industry and Security (Department of Commerce) is required for the aircraft under the Export Administration Regulations (15 CFR parts 730 through 774). Aircraft are not required to clear if the Secretary of Commerce issues a permit allowing departure without clearance.
(c) Department of State. Aircraft not covered by Export Administration Regulations are subject to the Department of State export licensing authority as set out in 22 CFR parts 121 and 123. Such aircraft may depart from the U.S. only with the proper Department of State license.