In blade station numbering, what is the order of increase?

• A. From tip to hub
• B. From root to tip
• C. From hub to tip
• D. From leading edge to trailing edge

Answer: (B)

The measurement increases along the blade from where it mounts to the hub (the root) outward toward the tip. In blade station numbering, you start at the root and move toward the tip, so the numbers grow as you go out along the blade span. The root corresponds to the attachment area, and the tip is the outer end of the blade, which keeps the reference consistent for locating features and performing inspections.

Choosing a direction from tip to hub would use the reverse order, which isn’t the standard convention. Saying from hub to tip is close in meaning but uses the term hub instead of the more precise root, and the option describing leading edge to trailing edge refers to chordwise, not spanwise, position.