Final answer:
The glide slope is the ILS component that sends out a vertical beam for vertical guidance during an instrument approach, aiding pilots in staying aligned with the runway.
Step-by-step explanation:
The component of the Instrument Landing System (ILS) that sends out a vertical beam along the centerline of the runway to help the pilot stay aligned with the runway during an instrument approach is the glide slope. The localizer beam provides horizontal guidance to ensure the aircraft is aligned with the centerline of the runway, while the glide slope provides vertical guidance to ensure the aircraft is on the correct descent path. Neither the taxiway nor the helipad is involved in helping pilots align with the runway during an approach.