Introduction / Context:
The Airport Reference Point (ARP) is a fundamental datum in aerodrome planning. It provides a single geodetic point used for identifying the aerodrome on maps and for referencing certain obstacle limitation surfaces.
Given Data / Assumptions:
- ARP approximates the geometric centre of the usable landing area (aerodrome proper).
- Horizontal and conical surface boundaries in obstacle limitation systems are referenced to the ARP.
- Map depictions of an aerodrome often position the symbol at the ARP.
Concept / Approach:
Because an aerodrome can have multiple runways and complex geometry, a single reference (ARP) simplifies cartographic representation and regulatory descriptions of protected airspace surfaces (e.g., horizontal and conical surfaces encircling the aerodrome planform).
Step-by-Step Solution:
1) Definition: The ARP is the approximate geometric centre of the landing area—statement 1 is correct.2) OLS referencing: Horizontal and conical surfaces use the ARP as their plan reference—statement 2 is correct.3) Mapping: The official position of the airport shown on charts is the ARP—statement 3 is correct.
Verification / Alternative check:
Review aerodrome chart legends and OLS diagrams; ARP coordinates are explicitly listed and used.
Why Other Options Are Wrong:
a/b/c/e: Each omits one or more true statements, whereas all three are correct together.
Common Pitfalls:
Confusing ARP with runway threshold coordinates or with the airport reference elevation (different concepts).
Final Answer:
All of the statements (1–3) are correct.
Discussion & Comments