Narrative:

On preflight; with the batteries on; once the inertial reference unit (IRU) were turned to align; the blue 'align on ref' was not displayed; nor were there alignment coordinates at 2 left and right. As a result I imputed the coordinates from the flight plan and then hit the prompts 'align on ref' and 'confirm' (not normal but not uncommon either). As I started to leave the cockpit; a 'ding' occurred. Instinctively looking back I saw the blue prompt again (which was odd; first time I had seen that). Again I pushed the blue 'align on ref' prompt followed by the amber 'confirm'; (without reconfirming the coordinates as I had just typed them in. I definitely should have rechecked in case an error was made. A potentially serious mistake; one I will never repeat). During push back I noticed a GPS inoperative advisory on the navigational display (nd); that disappeared after engine start. Prior to taking the runway; all looked normal and displays were normal during takeoff roll. The navigation system came up navigation on the nd shortly after takeoff (like normal). Problem was the heading the navigation display was showing to fly; was 30+ degrees right of our known heading 053. We pulled for heading and continued our climb out away from the ground. Unable to deduce the error; we tried direct to waypoint zzzzz; then the secondary flight plan. No help. Next I tried attitude hold (att) mode on irus (going from navigation to off to att) trying to fix the issue with the IRS and/or GPS; hopefully allowing for an in flight alignment. At one point I noticed the data on the FMC showing us a start point of zzzzz waypoint? This effort (going to att) caused the entire system to shut down. We discussed a return to ZZZ but were uncomfortable due to severe heading divergence from known (IRS/GPS issue) and the high altitude airport; heavy/overweight landing in a mountainous terrain environment. Although a declaration did not occur; ATC was fully aware of our situation giving us exceptional handling to the north; away from mountainous terrain; traffic and towards VMC weather. We discussed northern divert options. Unfortunately; we were unable to get weather via ACARS for these options. Knowing we could not enter rvsm airspace; we requested FL270 and leveled there while continuing northeast. Shortly thereafter; while trying to trouble shoot the IRU/GPS issue; we lost the cabin pressurization. This required a descent. We could not descend to 10;000ft due to terrain so we descended to 15;000ft. Able to catch the cabin altitude manually; we stayed at 15;000.we continued flying in a northerly direction utilizing the wet compass only; no nd assistance. The att mode did provide us pfd airspeed and altitude. ATC was able to give us ZZZZ2 weather (300-1) which we decide was not our best choice (ATC was unable to give us us airport weather). When we overflew ZZZZ3; and it was VFR; we deemed it suitable and we landed. Following were among the numerous checklists run:navigation/GPS primary lossnav/ir 1-2; 2-3 and 1-3 faultsnav/ir align in att modeplus manually running the pressurization schedule following the QRH checklist. APU on; flaps 3 uneventful landing completed. Post landing; during rollout; the brakes felt normal about 100kts; slowing at the end of the runway (to turn around and back-taxi); the brakes went to the floor (20mph?). I went full reverse while the first officer (first officer) jumped on binders with me. Feeling we weren't slowing enough; as I was reaching for the a/skid NWS disct switch; the first officer grabbed the parking brake bringing us to a quick stop (speed about 5mph). We were both thinking yellow system brakes just different ways to get there. The brakes returned. As we taxied very slowly to parking stand (brakes felt normal but getting intermittent ECAM brks caution); we queried about 'tow equipment if necessary'. We opted to continue taxi to gate. Uneventful. After passengers debriefed and [maintenance] contacted (via station operations cell phone; minedoes not work here) a thorough debriefing ending with maintenance control stating they would enter into [maintenance computer] our issues. Maintenance control then transferred us to the duty manager and we debriefed again. I asked to pass onto our dispatcher our scenario/issues and why I could not contact him (ACARS inoperative). Once phone calls complete; the first officer and I performed a post-flight walk around. Pilot tubes and tires (complete walk around) were all checked thoroughly. No issues noted.

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Original NASA ASRS Text

Title: An Airbus A320 flight crew reported that the entire navigation system completely shut down along with the aircraft pressurization system.

Narrative: On preflight; with the batteries on; once the Inertial Reference Unit (IRU) were turned to align; the blue 'align on ref' was not displayed; nor were there alignment coordinates at 2 L and R. As a result I imputed the coordinates from the flight plan and then hit the prompts 'align on ref' and 'confirm' (not normal but not uncommon either). As I started to leave the cockpit; a 'ding' occurred. Instinctively looking back I saw the blue prompt again (which was odd; first time I had seen that). Again I pushed the blue 'align on ref' prompt followed by the amber 'confirm'; (without reconfirming the coordinates as I had just typed them in. I definitely should have rechecked in case an error was made. A potentially serious mistake; one I will never repeat). During push back I noticed a GPS INOP advisory on the Navigational Display (ND); that disappeared after engine start. Prior to taking the runway; all looked normal and displays were normal during takeoff roll. The NAV system came up NAV on the ND shortly after takeoff (like normal). Problem was the heading the NAV display was showing to fly; was 30+ degrees right of our known heading 053. We pulled for heading and continued our climb out away from the ground. Unable to deduce the error; we tried direct to waypoint ZZZZZ; then the secondary flight plan. No help. Next I tried Attitude Hold (ATT) mode on IRUs (going from NAV to OFF to ATT) trying to fix the issue with the IRS and/or GPS; hopefully allowing for an in flight alignment. At one point I noticed the data on the FMC showing us a start point of ZZZZZ Waypoint? This effort (going to ATT) caused the entire system to shut down. We discussed a return to ZZZ but were uncomfortable due to severe heading divergence from known (IRS/GPS issue) and the high altitude airport; heavy/overweight landing in a mountainous terrain environment. Although a declaration did not occur; ATC was fully aware of our situation giving us exceptional handling to the north; away from mountainous terrain; traffic and towards VMC weather. We discussed northern divert options. Unfortunately; we were unable to get weather via ACARS for these options. Knowing we could not enter RVSM airspace; we requested FL270 and leveled there while continuing northeast. Shortly thereafter; while trying to trouble shoot the IRU/GPS issue; we lost the cabin pressurization. This required a descent. We could not descend to 10;000ft due to terrain so we descended to 15;000ft. Able to catch the cabin altitude manually; we stayed at 15;000.We continued flying in a northerly direction utilizing the wet compass ONLY; no ND assistance. The ATT mode did provide us PFD airspeed and altitude. ATC was able to give us ZZZZ2 weather (300-1) which we decide was not our best choice (ATC was unable to give us US airport weather). When we overflew ZZZZ3; and it was VFR; we deemed it suitable and we landed. Following were among the numerous checklists run:NAV/GPS primary lossNAV/IR 1-2; 2-3 and 1-3 faultsNAV/IR align in ATT modeplus manually running the pressurization schedule following the QRH checklist. APU on; flaps 3 uneventful landing completed. Post landing; during rollout; the brakes felt normal about 100kts; slowing at the end of the runway (to turn around and back-taxi); the brakes went to the floor (20mph?). I went full reverse while the First Officer (FO) jumped on binders with me. Feeling we weren't slowing enough; as I was reaching for the A/SKID NWS disct switch; the FO grabbed the parking brake bringing us to a quick stop (speed about 5mph). We were both thinking yellow system brakes just different ways to get there. The brakes returned. As we taxied very slowly to parking stand (brakes felt normal but getting intermittent ECAM brks caution); we queried about 'tow equipment if necessary'. We opted to continue taxi to gate. Uneventful. After passengers debriefed and [maintenance] contacted (via station operations cell phone; minedoes not work here) a thorough debriefing ending with Maintenance Control stating they would enter into [Maintenance computer] our issues. Maintenance Control then transferred us to the duty manager and we debriefed again. I asked to pass onto our dispatcher our scenario/issues and why I could not contact him (ACARS INOP). Once phone calls complete; the FO and I performed a post-flight walk around. Pilot tubes and tires (complete walk around) were all checked thoroughly. No issues noted.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.