NDB navaids
Non-Directional Beacons — low/medium-frequency beacons flown with an ADF. 6,610 on record.
| Ident | Name | Country |
|---|---|---|
| OU | Osh | 🇰🇬 KG |
| OO | Oshawa | 🇨🇦 CA |
| XA | Oshima | 🇯🇵 JP |
| OKS | Oshkosh | 🇺🇸 US |
| OSJ | Osijek | 🇭🇷 HR |
| OOA | Oskaloosa | 🇺🇸 US |
| OS | Osmino | 🇷🇺 RU |
| OSO | Osorno | 🇨🇱 CL |
| OS | Ossora | 🇷🇺 RU |
| OST | Ostia | 🇮🇹 IT |
| DAL | Otaebe | 🇸🇾 SY |
| MG | Otims | 🇺🇸 US |
| FMH | Otis | 🇺🇸 US |
| OW | Otjiwarongo | 🇳🇦 NA |
| OPE | Otopeni | 🇷🇴 RO |
| OPW | Otopeni | 🇷🇴 RO |
| OTR | Otopeni | 🇷🇴 RO |
| OTL | Otopeni | 🇷🇴 RO |
| GT | Otrokovice | 🇨🇿 CZ |
| CU | Otsu | 🇯🇵 JP |
| OW | Ottawa | 🇨🇦 CA |
| PDR | Ottawa | 🇺🇸 US |
| OUA | Ouagadougou | 🇧🇫 BF |
| AJ | Ouani | 🇰🇲 KM |
| ORZ | Ouarzazate | 🇲🇦 MA |
| OH | Oudtshoorn | 🇿🇦 ZA |
| OU | Ouesso | 🇨🇬 CG |
| CNU | Oujda | 🇲🇦 MA |
| ORH | Ourinhos | 🇧🇷 BR |
| OA | Ouvea | 🇳🇨 NC |
| OVD | Ovda | 🇮🇱 IL |
| OB | Overberg | 🇿🇦 ZA |
| DW | Owaso | 🇺🇸 US |
| OW | Owerri | 🇳🇬 NG |
| OX | Oxford | 🇬🇧 GB |
| OXD | Oxford | 🇺🇸 US |
| 4N | Oxford House | 🇨🇦 CA |
| DC | Oxonn | 🇺🇸 US |
| OY | Oyem | 🇬🇦 GA |
| OZ | Ozamis | 🇵🇭 PH |
| OC | Ozuki | 🇯🇵 JP |
| W7 | Pabok (Du Rocher-Perce) | 🇨🇦 CA |
| PAI | Pacoima | 🇺🇸 US |
| OQ | Padang | 🇮🇩 ID |
| PDV | Padova | 🇮🇹 IT |
| PHA | Pafos | 🇨🇾 CY |
| PN | Pagadian | 🇵🇭 PH |
| PYG | Pageland | 🇺🇸 US |
| PGN | Pagerungan | 🇮🇩 ID |
| TUT | Pago Pago | 🇦🇸 AS |