Instrument Flight Rules (IFR)

Definition

Instrument Flight Rules (IFR) are a set of aviation regulations under which a pilot operates an aircraft primarily using instruments for navigation and control, rather than visual references. IFR is required when flying in Instrument Meteorological Conditions (IMC) or in certain controlled airspace regardless of weather conditions. Pilots must be instrument-rated, and aircraft must be equipped and certified for IFR operations.

Purpose

Allow flight in poor visibility or cloudy conditions (IMC)
Enable safe navigation in high-traffic or controlled airspace
Provide positive ATC separation from other traffic and terrain
Standardize procedures for departures, enroute operations, and approaches

When IFR Is Required

In IMC (weather below VFR minima)
In Class A airspace (always IFR)
For airline and commercial transport flights
For instrument approaches and flights at night (in some jurisdictions)
When filing an IFR flight plan (mandatory for IFR)

IFR Flight Requirements

Requirement	Description
Pilot license	Must hold an Instrument Rating (IR)
Aircraft equipment	Must include gyroscopic instruments, nav/com radios, transponder, and alternates
Flight plan	IFR flight plan must be filed and activated
ATC clearance	Required before entering controlled airspace or departure under IFR
Communication	Continuous two-way radio contact with ATC

IFR vs. VFR

Feature	IFR	VFR
Navigation	Instruments	Visual references
ATC separation	Provided	Not guaranteed
Weather requirements	IMC or VMC	VMC only
Airspace access	All classes (A–G)	Restricted in some airspace
Pilot certification	Instrument rating required	Private or commercial license
Typical use	Airlines, IFR routes, IMC	General aviation, local flights

Phases of IFR Flight

Clearance and start-up
SID (Standard Instrument Departure)
Enroute navigation using airways or RNAV
STAR (Standard Arrival Route) or vectoring
Instrument approach (e.g., ILS, RNAV, VOR)
Missed approach if required
Landing and taxi under ATC guidance

Phraseology Examples

“Cleared to Munich via ROTAX 2N departure, climb FL90.”
“Descend to 3000 feet, expect ILS runway 08.”
“Maintain FL280, contact Vienna Radar on 132.1.”

IFR Flight Planning

Must include: departure, route, alternate airport, and fuel calculation
Requires filing at least 60 minutes before departure (domestically may vary)
ATC may issue amended routes or expected clearances
IFR flight plans are filed in ICAO format (FPL)

Tips for IFR Pilots

✅ Keep charts, frequencies, and checklists ready and organized
✅ Anticipate clearances and altitude changes
✅ Practice hold entries, missed approaches, and diversions
✅ Use LearnATC’s IFR modules to build fluency with clearances, STARs, and real-world navigation scenarios