When departing from a helipad, the distance threshold is measured from which reference?

• A. the road map center
• B. nearest aircraft location
• C. the runway end
• D. the helipad center

Answer: (D)

The distance threshold for departing a helipad is measured from the center of the helipad. This center serves as a fixed, consistent origin from which obstacle clearance and takeoff distance are calculated, ensuring a symmetrical and predictable reference point regardless of pad size or shape.

Other references aren’t appropriate: the road map center isn’t a flight reference, and the nearest aircraft location isn’t a fixed origin but a moving target. The runway end applies to fixed-wing operations, not rotorcraft departures from a helipad. Using the helipad center keeps the reference point uniform and tied to the actual takeoff point.