The scope of this document, although limited to human factors issues, is actually quite broad. Hardware/software design, displays and controls, aircraft stability, power margins, and pilot training, to name a few, all bring their own human factors issues to the overall objective of integrating vertical flight aircraft into the NAS. This document is a compilation of human factors issues relating to vertical flight systems. It is intended that the document be a living report of the human factors health of vertical flight as well as provide an historical perspective of the issues that have been considered. It will be updated to reflect research activities as they affect the issues.