14 CFR § 77.23 - Heliport imaginary surfaces.

---
identifier: "/us/cfr/t14/s77.23"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 77.23 - Heliport imaginary surfaces."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "77.23"
section_name: "Heliport imaginary surfaces."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "E"
subchapter_name: "AIRSPACE"
part_number: "77"
part_name: "SAFE, EFFICIENT USE, AND PRESERVATION OF THE NAVIGABLE AIRSPACE"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 106 (g), 40103, 40113-40114, 44502, 44701, 44718, 46101-46102, 46104."
regulatory_source: "Docket FAA-2006-25002, 75 FR 42303, July 21, 2010, unless otherwise noted."
cfr_part: "77"
---


# 77.23 Heliport imaginary surfaces.

(a) *Primary surface.* The area of the primary surface coincides in size and shape with the designated take-off and landing area. This surface is a horizontal plane at the elevation of the established heliport elevation.

(b) *Approach surface.* The approach surface begins at each end of the heliport primary surface with the same width as the primary surface, and extends outward and upward for a horizontal distance of 4,000 feet where its width is 500 feet. The slope of the approach surface is 8 to 1 for civil heliports and 10 to 1 for military heliports.

(c) *Transitional surfaces.* These surfaces extend outward and upward from the lateral boundaries of the primary surface and from the approach surfaces at a slope of 2 to 1 for a distance of 250 feet measured horizontally from the centerline of the primary and approach surfaces.