Some aircraft with an angle of incidence or cambered airfoils are capable of climb without any angle of attack, Is there a V speed for the speed at which an aircraft starts a positive climb?
No, there is no V-Speed associated with zero angle of attack, nor is climb associated with angle of attack. Since zero angle of attack does not directly translate to minimum drag for a production aircraft in operation, it is not a meaningful performance gate, which is what V-Speeds are designed to represent.
However, this is not to say that having a zero flow incidence against the fuselage is not desirable:
- If the body-axis is aligned with the fuselage longitudinal axis, it would be desirable from a passenger comfort standpoint to fly at zero AOA during level cruise. We don't want to have an inclined martini glass for the whole duration of the flight.
- Non-zero flow incidence against the fuselage does create drag. It would be desirable from a performance perspective to decrease any form of drag during cruise or climb.
This is achieved during aircraft design. The wing setting angle against the fuselage is tuned such that the average operational flow incidence angle against the fuselage is minimized.