---
title: "Datum — EASA Definition · Avioverse"
description: "Article 2, Regulation (EU) No 923/2012: ‘datum’ means any quantity or set of quantities that may serve as a reference or basis for the calculation of…"
url: "https://avioverse.aero/glossary/easa/datum"
---

# datum

EASA defines “datum” in 2 regulations, worded for each regulation's scope. The wording below is reproduced verbatim from the EASA Easy Access Rules, with a link to the paragraph it comes from.

> ‘datum’ means any quantity or set of quantities that may serve as a reference or basis for the calculation of other quantities;

Article 2 · Standardised European Rules of the Air (SERA) · Regulation (EU) No 923/2012 · Easy Access Rules, 26 Aug 2025 revision · [Read Article 2](https://avioverse.aero/regulations/easa/sera/cover-regulation/powers-and-recital#article-2)

> ‘Datum’ means any quantity or set of quantities that may serve as a reference or basis for the calculation of other quantities (ISO 19104).

CS ADR-DSN.A.002 · Aerodromes · Regulation (EU) No 139/2014 · Easy Access Rules, 13 Mar 2026 revision · [Read CS ADR-DSN.A.002](https://avioverse.aero/regulations/easa/aerodromes/cs-adr-dsn/chapter-a-general#cs-adr-dsn-a-002)

## Also in the aviation glossary

- Datum (Reference Datum) FAA PHAK

  An imaginary vertical plane or line from which all measurements of arm are taken. The datum is established by the manufacturer. Once the datum has been selected, all moment arms and the location of CG range are measured from this point.

## Defined in the same article

- [accelerate-stop distance available (ASDA)](https://avioverse.aero/glossary/easa/accelerate-stop-distance-available)
- [accuracy](https://avioverse.aero/glossary/easa/accuracy)
- [advisory airspace](https://avioverse.aero/glossary/easa/advisory-airspace)
- [advisory route](https://avioverse.aero/glossary/easa/advisory-route)
- [aerial work](https://avioverse.aero/glossary/easa/aerial-work)
- [aerobatic flight](https://avioverse.aero/glossary/easa/aerobatic-flight)
- [aerodrome](https://avioverse.aero/glossary/easa/aerodrome)
- [Aerodrome beacon](https://avioverse.aero/glossary/easa/aerodrome-beacon)