# Instrument Flight Rules (IFR): Minimum Levels, Equipment, and Vertical Separation

> Study IFR requirements for minimum altitudes, route equipment, RVSM versus non-RVSM separation, and arrival reporting to close flight plans.

- **Subject:** 010 — Air Law
- **Section:** 010-05 — Rules of the Air According to ICAO Annex 2 and SERA
- **Topic code:** 010-05-05
- **Last reviewed:** 2026-03-27
- **Author:** Pablo Asensio Martínez
- **HTML version:** https://pilotsyllabus.com/en/air-law/rules-of-the-air-according-to-icao-annex-2-and-sera/instrument-flight-rules-ifr/

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Instrument Flight Rules (IFR) allow operation without external visual references, relying on aircraft instruments.

## Minimum Levels (ICAO Annex 2, 5.1.2)
Except for takeoff or landing, an IFR flight shall be flown at a level which is not below the minimum flight altitude established by the State. If not established:
*   **Over high terrain or in mountainous areas:** At least **600 m (2000 ft)** above the highest obstacle located within 8 km of the estimated position of the aircraft.
*   **Elsewhere (flat terrain):** At least **300 m (1000 ft)** above the highest obstacle located within 8 km of the estimated position of the aircraft.

## Equipment
The aircraft shall be equipped with suitable instruments and navigation equipment appropriate to the route (minimum one VOR, one ADF -if necessary-, and one DME according to EASA, or as appropriate according to ICAO).

## Vertical Separation
*   **RVSM (Reduced Vertical Separation Minima):** Between FL290 and FL410, vertical separation is **1000 ft**.
*   **Non-RVSM:** Above FL290, standard separation is **2000 ft**.

Due to the semicircular rule:
*   In Non-RVSM airspace, two aircraft flying in the same direction (same track, e.g., East) will be separated by **4000 ft** (e.g., FL290, FL330, FL370).
*   In RVSM airspace, they will be separated by **2000 ft** (e.g., FL290, FL310, FL330).

## Termination of Flight Plan
A flight plan shall be closed by an arrival report to the appropriate ATS unit after landing. The report includes aircraft identification, departure aerodrome, destination, arrival aerodrome, and time of arrival.

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Free study notes from pilotsyllabus.com. Not a substitute for training at an approved ATO.