Later airways were based on low / medium frequency ground stations, like the beat frequency oscillator ( BFO ) and the non-directional beacon ( NDB ).
32.
Waypoints use five letters ( e . g ., PILOX ), and those that double as non-directional beacons use three or two ( TNN, WK ).
33.
On 15 July 1960, at 09 : 04, "'Ethiopian Air Lines Flight 372 "', a C-47 Skytrain non-directional beacon ( NDB ) to assist his navigation.
34.
Some countries, such as Canada, have abandoned marker beacons completely, replacing the outer marker with a non-directional beacon ( NDB ); and, more recently, with GPS fixes.
35.
"' Condor Flugdienst Flight 3782 "'was an international charter flight from ILS approach to the Outer Marker ( Non-Directional Beacon ) and then on to Runway 35.
36.
The Otjiwarongo non-directional beacon ( Ident : "'OW "') is near the in-town location of the former Otjiwarongo Center Airport ( closed ), southwest of the current airport.
37.
Other navigational aids nearby are the Spartanburg Vortac ( VOR ) ( 7.2 miles northeast ) and the Fairmont Non-directional beacon ( NDB ) ( 1.6 miles west ).
38.
After departing Rome Ciampino at 14 : 16, it crossed the Mediterranean via Bastia in Corsica, whence the flight plan called for it to pass over the Istres non-directional beacon.
39.
VHF omnidirectional range ( VOR ) stations became the predominant means of route navigation during the 1960s, superseding the low frequency radio ranges and the non-directional beacon ( NDB ).
40.
The two controllers provided radio communications, set up and maintained a non directional beacon navigation aid, provided weather observations and updated airfield status reports helping to ensure safe air operations.
