Air carrier flight crew reported GPS malfunction at 34000 ft. in the vicinity of IAD. Dispatch informed the flight crew there were system-wide outages for both Boeing and Airbus aircraft.
Synopsis
Air carrier flight crew reported GPS malfunction at 34000 ft. in the vicinity of IAD. Dispatch informed the flight crew there were system-wide outages for both Boeing and Airbus aircraft.
Narrative
Operating ZZZ to IAH as pilot monitoring. During cruise near IAD at FL340 we got a scratchpad message GPS-R INVALID." We cleared the message and got the same one for the left GPS. Checked Inertial Reference System (IRS) drift and ANP to ensure the accuracy of our position. We verified the GPS outage on the navigation status page of the FMC which showed GPS (). This coincided with the transponder fail light illuminating. We queried ATC to see if there were any reported GPS outages and also asked if they were showing our transponder on. ATC informed us that our transponder was operational and they were not aware of any GPS outages. Captain then gave me the airplane and the radios while he entered the QRH GPS unreliable non-normal. By the time we got into the checklist both GPS's came back. We read the checklist anyway to make sure everything was complied with. He followed this up with an Electronic Logbook (ELB) entry and a message to Dispatch via ACARS. We experienced similar scratchpad messages and apparent invalid GPS approximately 5 more times during the flight; with the last one occurring near the final approach segment. We landed in IAH via an ILS safely with no further issues."
Second reporter narrative
Operating flight started out routine. When we got to cruise altitude; around the IAD area FL340 we got a scratchpad message GPS-L INVALID." After clearing the message we got another "GPS-R INVALID." We made sure to check our Inertial Reference System (IRS) drift to ensure accuracy of navigation. We did so by turning on POS on the Navigation Display (ND). Everything looked normal ANP was 0.02 NM. We checked our navigation status and it showed GPS ( ) indicating both are invalid. The only thing accompanying that was an illuminated XPDR (Transponder) FAILED light on the transponder panel. We immediately questioned ATC to confirm our transponder status. ATC informed us that everything is displaying as normal on their end. We then referenced the QRH GPS Unreliable Non-normal. By the time we pulled the checklist which was less than 30 seconds the L GPS came back; then shortly after then R GPS came back. We read over the QRH to make sure everything is complied with. We informed Dispatch via ACARS and submitted an Electronic Log Book (ELB). Dispatch informed us that there were system-wide outages for the MAX aircraft as well as the Airbus NEOs. We continued normal to IAH. This problem occurred 5 more times all in the same order all lasting no longer than 2 - 3 minutes with no threat to the safety of the flight. We landed in IAH with no further issues."
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.