According to the FAA, "certain aircraft equipped with the Rockwell Collins GPS 4000-100 and select ADS-B out GPS receivers are indicating 'ADS-B fail, unavailable, TCAS fail or transponder fail' messages." Aircraft without working transponders were directed to coordinate with the FAA before departure, a prior directive had instructed those planes not to fly above 28,000 feet.
Various online reports suggested impacted planes were mostly CRJ jets made by Canada’s Bombardier, but also some Boeing 737s, 717s and possibly a 767 as well. "We are working to determine the cause of the problem," the FAA said in a statement, "which may have resulted from a software update to the aircraft navigation systems."
There was no immediate response or comment available from Collins Aerospace.
"GPS isn’t down," Hackaday reported, as anyone with a smartphone can see easily enough. "However, it is degraded.
The root cause is a software design error that misinterprets GPS time updates. A "leap second" event occurs once every 2.5 years within the US Government GPS satellite almanac update. Our GPS-4000S (P/N 822-2189-100) and GLU-2100 (P/N 822-2532-100) software's timing calculations have reacted to this leap second by not tracking satellites upon power-up and subsequently failing. A regularly scheduled almanac update with this “leap second” was distributed by the US Government on 0:00GMT Sunday June 9, 2019 and the failures began to occur after this event.
Основа - это FMC. А все остальное - нужно для ее работы. IRS нужны для инициализации и для счисления координат при отсутствии средств коррекции. Если есть GPS, то ее координаты имеют приоритет.Сергей67, да даже не НЛ.
Знающие люди писали на этом форуме, что основа навигации лайнеров - все-таки ИНС, а GPS и радионавигация для ее коррекции