HAPI

FAA HAPI

A helicopter approach path indicator (HAPI) is a visual glideslope indicator (VGSI), providing visual vertical course and descent cues for pilots. A HAPI system consists of:

• 4 identical light units (type L-880) or 2 identical light units (type L-881)
• A power control unit for style A systems only
• Aiming and calibration equipment (may be part of the light units)

PAPI units may be voltage powered (style A) or current powered (style B).
Class I systems operate -31 to 131° F (-35 to 55° C) whereas class II systems operate -67 to 131° F (-55 to 55° C).

While VSGs are optional for helipads, provide one if:

• Obstacle clearance, noise abatement, or traffic control procedures require a particular slope.
• The environment of the heliport provides few visual surface cues.

References

• FAA AC 150-5390-2 – Heliport Design
• FAA AC 150/5340-30 – Design and Installation Details for Airport Visual Aids
• FAA AC 150-5345-28H – Precision Approach Path Indicator (PAPI) Systems

ICAO HAPI

Install a visual approach slope indicator (VASI) to serve the heliport approach to a heliport if one or more of the following conditions exist, especially at night:

• Obstacle clearance, noise abatement or traffic control procedures require a particular slope.
• The heliport environment provides few visual surface cues.
• The characteristics of the helicopter require a stabilized approach.

A standard VASI for helicopter operations consists of the following:

• PAPI and APAPI systems conforming to the Annex 14, Volume I specifications, except that the angular size of the on-slope sector of the systems shall be increased to 45 minutes; or
• Helicopter approach path indicator (HAPI) system conforming to Annex 14, Volume I specifications.

The HAPI signal format includes 4 discrete signal sectors, providing an “above slope”, an “on slope”, a “slightly below” and a “below slope” signal. The signal repetition rate of the flashing sector should be at least 2 Hz.

Light Distribution