D.C. Code § 7-205

(d) When a birth occurs on a moving conveyance within the United States and the child is first removed from the conveyance in the District, the birth shall be registered in the District, and the place where it is first removed shall be considered the place of birth. When a birth occurs on a moving conveyance while in international waters, air space, in a foreign country or its air space, and the child is first removed from the conveyance in the District, the birth shall be registered in the District, but the certificate shall show the actual place of birth insofar as can be determined.

UPDATE: Turns out this is model language. The 1992 Model State Vital Statistics Act can be found here, and there is a new Model Act in the review process.