GPS Week Rollover grounds Aussie weather balloons, Boeing planes

Launch of a weather balloon in Australia. (Photo: Townsville Meteorological Office/Bureau of Meteorology)

The GPS Week Number Rollover, which took place April 6, has grounded the Australian Bureau of Meteorology’s (BOM) weather balloons.

The fault was caused by the rollover of the time stamp in GPS signals, reports ABC news, which caused a  “technical fault with the equipment’s communications systems.”

The weather balloons carry a radiosonde that includes GPS tracking. The radiosondes measure various atmospheric parameters and transmits them by radio to a ground receiver.

BOM said its equipment supplier advised the bureau of the fault after the rollover on April 7, and balloon launches ceased on April 8.

GPS clocks returned to zero early on Sunday morning.

Usually, BOM launches 56 weather balloons each day from 38 locations to provide vital information to help meet international obligations under the Convention of the World Meteorological Organization.

Boeing aircraft affected

Also affected by the rollover were some Boeing aircraft. The GPS clock rollover caused “a limited number of 787 airplanes” to display the wrong date, according to Boeing, causing them to be temporarily grounded in China.

Other reports are that at least one KLM 777 flight and a large number of China Airlines 777 and 787 aircraft were grounded due to the issues, while technicians updated the software. A Shanghai Airlines 787 was also reportedly affected.

In all the reported cases so far, the GPS systems were supplied by Honeywell, which issued a service update on the issue.