Instrument Rating (IR)
IFR procedures, holds, approaches, and regulations for Instrument Rating study and qualification.
The Instrument Rating (IR) allows pilots to fly in Instrument Meteorological Conditions (IMC). It requires additional training beyond the PPL, specific equipment, and both written and flight tests. IFR operations demand precise adherence to published procedures and ATC instructions.
IFR vs VFR
| Aspect | VFR | IFR |
|---|---|---|
| Weather minima | VMC required | IMC permitted |
| Flight plan | Optional (recommended) | Mandatory (most jurisdictions) |
| ATC | Not mandatory (outside controlled) | Continuous two-way radio required |
| Separation | Self-separation (see-and-avoid) | ATC-provided separation |
| Altitude/level | Cruise altitude by quadrant rule | ATC-assigned flight levels |
| Equipment | Basic VFR instruments | Full IFR panel + equipment codes |
IFR Altimetry
Altitude Types
| Term | Reference | Use |
|---|---|---|
| QNH | MSL pressure — local | Below transition altitude |
| QNE (Flight Level) | 1013.25 hPa / 29.92 inHg | Above transition level |
| QFE | Aerodrome elevation pressure | Height above aerodrome (some aerodromes) |
QNH → FL transition: change altimeter at transition altitude (TA) when climbing, at transition level (TL) when descending.
Semi-Circular Rule (Quadrantal Rule)
IFR altitude selection by magnetic track:
- 000°–179° (North, East): Odd flight levels — FL290, FL310, FL330…
- 180°–359° (South, West): Even flight levels — FL300, FL320, FL340…
- (RVSM above FL290 — 1000 ft separation)
Holds (Holding Patterns)
A holding pattern is a racetrack-shaped flight path used to absorb delay. Standard holds are right-hand (right turns). Non-standard (left-hand) holds are indicated on charts.
Standard hold parameters: 1-minute legs below FL140, 1.5-minute legs at/above FL140.
Hold Entry Procedures
| Entry Type | When Used (relative bearing from outbound heading to fix) |
|---|---|
| Parallel entry | 110° either side of the outbound heading (opposite side to hold) |
| Teardrop entry | 70° on the non-holding side |
| Direct entry | Remaining 180° sector |
Hold Timing
- Time the outbound leg from abeam the fix (or from wings level if turn is steep)
- Adjust outbound time to achieve 1-minute inbound leg (compensate for wind)
- Speed limits in holds: max 230 kt below FL140, 240 kt FL140–FL200, 265 kt FL200–FL340, 280 kt or Mach 0.83 above FL340
Instrument Approach Procedures
Approach Segments
| Segment | From | To | Purpose |
|---|---|---|---|
| Arrival | En-route | Initial approach fix (IAF) | Transition from en-route to approach |
| Initial approach | IAF | Intermediate fix (IF) | Manoeuvring to align with final |
| Intermediate | IF | Final approach fix (FAF) | Aircraft configured and stabilised |
| Final approach | FAF | MAP or runway | Descent to minimums |
| Missed approach | MAP | Holding fix | Procedure if landing not possible |
Crew callouts on approach: "localiser alive", "glide slope alive", "localiser captured", "glide slope captured", "decision height" or "minimums", "landing / going around". These ensure both crew are monitoring the same parameters.
IFR Navigation and Tracks
Minimum Safe Altitudes
- MSA (Minimum Sector Altitude): 25 nm radius around navaid, provides 1000 ft terrain clearance
- MORA (Minimum Off-Route Altitude): from grid charts, provides 1000 ft clearance (2000 ft in mountains)
- MEA (Minimum Enroute Altitude): ensures obstacle clearance and navaid reception on airways
- MOCA (Minimum Obstruction Clearance Altitude): terrain clearance, may not guarantee navaid reception
IR Regulations
Key regulations to know:
- IMC definition: ceilings below VFR minima or visibility below VFR minima
- PIC currency: 6 approaches in last 6 months (varies by authority)
- Alternate fuel requirements: sufficient to fly to alternate + 30 min reserve
- Equipment requirements: dual VHF, standby instruments, DME, IFR GPS/RNAV typically required
- IFR flight plan required 30 minutes before EOBT in most jurisdictions
Also Study
- Approach charts reading and interpretation
- SID/STAR interpretation
- Oxygen requirements for high-altitude operations
- ETOPS concepts
- RVSM operations and requirements
- Crew incapacitation procedures