← Standards & Specs
The Toolbox — Standards
Aviation
FCC and FAA aviation radio frequency allocations, transponder specs, and aircraft electrical standards.
| Specification | Value / Notes |
|---|---|
| VHF aviation communication band | 118.000 – 136.975 MHz |
| Aviation emergency frequency | 121.5 MHz (civilian) / 243.0 MHz (military) |
| VOR navigation band | 108.000 – 117.950 MHz |
| ILS localizer band | 108.10 – 111.95 MHz (odd tenths only) |
| ILS glideslope band | 329.15 – 335.00 MHz |
| Marker beacon frequency | 75 MHz (all three markers) |
| DME operating band | 960 – 1215 MHz |
| Transponder interrogation frequency | 1030 MHz |
| Transponder reply frequency | 1090 MHz |
| ADS-B Out frequency | 1090 MHz |
| ELT frequency | 406 MHz (satellite) + 121.5 MHz (homing) |
| Radio altimeter band | 4200 – 4400 MHz |
| Aircraft VHF typical TX power | 20 watts |
| Aircraft HF typical TX power | 100 watts |
| Aircraft DC power standard | 28V DC on most newer GA, turbine and transport aircraft; 14V on many older light aircraft |
| Aircraft AC power standard | 115V AC, 400 Hz, 3-phase |
| 400 Hz advantage over 60 Hz | Transformers and motors 1/7 the size — critical for weight |
| Transponder altitude encoding increment | 100-foot increments (Gillham/Gray code) |
| Mode C altitude range | −1,000 to 126,700 feet (encoders usually cover less) |
| ADS-B mandate (US) | Required in Class A, B, C airspace and above 10,000 ft MSL since January 2020 |
| AN3 bolt, tension nut (MS20365/AN310) | 20-25 in*lb / 2.26-2.82 N*m |
| AN4 bolt, tension nut (MS20365/AN310) | 50-70 in*lb / 5.65-7.91 N*m |
| AN5 bolt, tension nut (MS20365/AN310) | 100-140 in*lb / 11.3-15.8 N*m |
| AN6 bolt, tension nut (MS20365/AN310) | 160-190 in*lb / 18.1-21.5 N*m |
| AN7 bolt, tension nut (MS20365/AN310) | 450-500 in*lb / 50.8-56.5 N*m |
| AN8 bolt, tension nut (MS20365/AN310) | 480-690 in*lb / 54.2-77.9 N*m |
| AN3 bolt, shear nut (MS20364/AN320) | 12-15 in*lb / 1.36-1.69 N*m |
| AN4 bolt, shear nut (MS20364/AN320) | 30-40 in*lb / 3.39-4.52 N*m |
| Torque values source | AC 43.13-1B Table 7-1, fine-thread bolts, dry threads |
| Always verify torque values against | Applicable aircraft maintenance manual (AMM) |