Two passenger flights landed in Canberra on Monday morning because they couldn't land at their scheduled destination of Sydney.
It's understood that the system of electronic beacons guiding the planes into Sydney weren't able to guide the planes in.
With both aircraft running too low on fuel to circle for long over Sydney, Canberra was the nearest airport capable of accepting the biggest jets at short notice.
The cause of the system inability is not known.
The unscheduled diversion meant that hundreds of passengers were ferried to Sydney at the end of their 14 hour flight across the international date line. It's thought that they went by bus.
Air Services Australia which runs the instrument landing system (ILS) had not responded to a request for information at the time of writing.
One of the flights was American Airlines 73, a Boeing 777-300. It can usually take 301 to 368 passengers in ten-abreast seating.
The other was United Airlines 839, a Boeing 787 Dreamliner. It can usually take 200 to 300 passengers.
One of the planes came to a stop at the terminal side of Canberra Airport and the other aircraft on the Fairbairn side. Buses ferried them to their intended destination from the Fairbairn side.
The passengers' feelings are not known. Their disappointment may have been assuaged by the sight of a full Lake George on the final leg.
