The atomic structure of ultralong carbon nanotubes obtained by catalytic chemical vapor deposition in the kite growth mode has been studied along the nanotube length via electron diffraction and high-resolution transmission electron microscopy. Contrary to other techniques, electron diffraction studies provide a direct determination of the chiral structure of nanotubes. These studies demonstrate that the chirality of the nanotubes remained constant all along their length (i.e., up to several hundreds of micrometers). A tendency of kite-growth nanotubes to be double-walled has been observed as well as a preferential distribution toward high-chiral angles configuration. Furthermore, the studies yield a metallic:semiconducting ratio close to the one expected from a natural distribution of nanotubes (1:2).