Key notes
Q codes
Section titled “Q codes”| Code | Meaning |
|---|---|
| QDM | Magnetic TO station |
| QDR | Magnetic FROM station |
| QUJ | True TO station |
| QTE | True FROM station |
Propagation and range
Section titled “Propagation and range”| Item | Value |
|---|---|
| Speed of light | 3 × 10⁸ m/s |
| Direct wave range | 1.23 × (√HT + √HR) nm |
| Ideal antenna length | ½ wavelength |
| HF comms modulation | SSB (J3E) |
| Duct layer thickness | ~1,000 ft max |
NDB / ADF
Section titled “NDB / ADF”| Item | Value |
|---|---|
| NDB frequency | 190–1750 kHz |
| Land range | 2 × √Power (W) nm |
| Sea range | 3 × √Power (W) nm |
| Double range | Power × 4 |
| QDM formula | MH + RB |
| ADF accuracy | ± 5° |
| Item | Value |
|---|---|
| Frequency | 108–117.95 MHz |
| Channel spacing | 50 kHz |
| Total channels | 160 |
| Each CDI dot | 2° |
| Full-scale deflection | 10° |
| VOR accuracy (95%) | ± 5° (worst ± 7.5°) |
| Monitor shutdown | Bearing ± 1° or signal −15% |
| Variation applied at | VOR station |
| Item | Value |
|---|---|
| Frequency | 962–1213 MHz (UHF) |
| Reply offset | ±63 MHz |
| Ground delay | 50 μs |
| Radar mile | 12.36 m/μs |
| Search mode | 150 pps |
| Tracking mode | 24–30 pps |
| Memory mode | 10 s |
| Capacity | ~100 aircraft |
| DME/P accuracy | ± 0.2 nm |
| Co-located (ENR/APP) | 2,000 ft / 100 ft |
| Item | Value |
|---|---|
| Localiser frequency | 108–112 MHz (odd) |
| Glideslope frequency | 329–335 MHz (UHF) |
| Markers | 75 MHz |
| LOC dot / full scale | 0.5° / 2.5° |
| G/S dot / full scale | 0.14° / 0.7° |
| LARD | Left/Above 90 Hz; Right/Down 150 Hz |
| ROD (3° G/S) | ≈ 5 × GS |
| CAT I DH / RVR | 200 ft / 550 m |
| CAT II DH / RVR | 100 ft / 300 m |
ILS markers
Section titled “ILS markers”| Marker | Distance | Tone |
|---|---|---|
| Outer | 4 nm | 400 Hz (blue) |
| Middle | 0.6 nm | 1,300 Hz (amber) |
| Inner | 0.04–0.24 nm | 3,000 Hz (white) |
| Item | Value |
|---|---|
| Radar mile | 12.36 m/μs |
| Double range (radar) | Power × 16 |
| SSR TX / RX | 1030 / 1090 MHz |
| Mode A interval | 8 μs |
| Mode C interval | 21 μs |
| AWR frequency | 9.375 GHz |
| AWR beam width | 3.5°–5° |
| AWR tilt | ± 15° |
| STC range | 60 nm |
SSR codes
Section titled “SSR codes”| Code | Meaning |
|---|---|
| 7500 | Hijack |
| 7600 | Radio failure |
| 7700 | Emergency |
| 2000 | Entering non-SSR airspace |
| Item | Value |
|---|---|
| Satellites | 24 (21 + 3 spares) |
| Orbit height | 20,200 km |
| Orbit period | 12 hrs |
| L1 frequency | 1,575.42 MHz |
| 2D / 3D fix | 3 / 4 satellites |
| RAIM with exclusion | 5 satellites |
| Mask angle | 5° or 7.5° |
| Almanac / Ephemeris | 24 hr / 2 hr update |
RNAV accuracy
Section titled “RNAV accuracy”| Type | Accuracy (95%) |
|---|---|
| B-RNAV | ± 5 nm |
| P-RNAV | ± 1 nm |
| 5-dot ENR | 1 dot = 1 nm |
| 5-dot APP | 1 dot = 0.25 nm |
Instrument summary
Section titled “Instrument summary”| Instrument | Wavelength | Frequency | Range |
|---|---|---|---|
| NDB/ADF | Hecto/kilometric | 190–1750 kHz | Land 2√P / Sea 3√P |
| VOR | Metric (VHF) | 108–118 MHz | 25–300 nm |
| DME | Decimetric (UHF) | 960–1215 MHz | 200 nm |
| ILS LOC | Metric (VHF odd) | 108–112 MHz | 25 nm : 10° |
| ILS G/S | Decimetric (UHF) | 329–335 MHz | 10 nm : 8° |
| MLS | Centimetric (SHF) | 5.03–5.09 GHz | ± 40° : 20 nm |
| AWR | Centimetric (SHF) | 9,375 MHz | 50–60 nm |
| GPS | Decimetric (UHF) | L1 1,575 MHz | Global |