GPS Week Number Rollover Apr 6/7
The airlines' software problems are most likely with Notices to Airman (NOTAMs). These are public domain data and announcements of airspace restrictions, etc. which AeroData, Inc. has been contracted by the FAA to provide since 1990. It looks like they do it for the EU, too. These announcements are part of the suite of software that AeroData provides. Every media outlet is mentioning weight and balance (read fuel load and cargo balancing for aircraft before take off) and completely missing the part that does airspace restriction, route and waypoint calculations that will certainly involve GPS information. Ya' gotta love the media...
On 2019-04-03 16:56, Chris Woodbury via tz wrote:
The airlines' software problems are most likely with Notices to Airman (NOTAMs). These are public domain data and announcements of airspace restrictions, etc. which AeroData, Inc. has been contracted by the FAA to provide since 1990. It looks like they do it for the EU, too.
These announcements are part of the suite of software that AeroData provides. Every media outlet is mentioning weight and balance (read fuel load and cargo balancing for aircraft before take off) and completely missing the part that does airspace restriction, route and waypoint calculations that will certainly involve GPS information. Ya' gotta love the media...
Looks like impacts appears to have been limited to unupgraded TomTom, Garmin, and Boeing devices, including at least 16 KLM and Chinese airlines' 777 and 787 Dreamliners with Honeywell flight management and navigation software: https://thenextweb.com/tech/2019/04/08/mercifully-the-gps-millennium-bug-was... https://arstechnica.com/information-technology/2019/04/gps-rollover-apparent... https://simpleflying.com/boeing-787-china-grounding/ Comments suggest future problems will be pushed back due to 13 bit extended week counts of 8192 week cycles in new 13 bit CNAV and MNAV messages, rolling over about 2137 Jan 05 Sat 23:59+0000, by which time GPS will be replaced. Older devices may not be updatable to take advantage of this, and may require checking if they are still around at 2038 Nov 20 Sat 23:59+0000. The precise second of future GPS times will depend on the number of leap seconds counted by GPS but added to and skipped in UTC. That assumes those devices did not use 32 bit time_t, common in embedded libraries and systems to save space and speed calculations, which rolls over, before the next GPS 1K week roll over if signed, at 2038 Jan 19 Tue 03:14:08+0000; or before the GPS 8K extended week number rollover, if unsigned, at 2106 Feb 07 Sun 06:28:16+0000. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised.
On 2019-04-10 07:45, Brian Inglis wrote:
On 2019-04-03 16:56, Chris Woodbury via tz wrote:
The airlines' software problems are most likely with Notices to Airman (NOTAMs). These are public domain data and announcements of airspace restrictions, etc. which AeroData, Inc. has been contracted by the FAA to provide since 1990. It looks like they do it for the EU, too.
These announcements are part of the suite of software that AeroData provides. Every media outlet is mentioning weight and balance (read fuel load and cargo balancing for aircraft before take off) and completely missing the part that does airspace restriction, route and waypoint calculations that will certainly involve GPS information. Ya' gotta love the media...
Looks like impacts appears to have been limited to unupgraded TomTom, Garmin, and Boeing devices, including at least 16 KLM and Chinese airlines' 777 and 787 Dreamliners with Honeywell flight management and navigation software:
https://thenextweb.com/tech/2019/04/08/mercifully-the-gps-millennium-bug-was...
https://arstechnica.com/information-technology/2019/04/gps-rollover-apparent...
More issues noted in comp.risks Risks Digest http://risks.org/ 31.18 2019 Apr http://catless.ncl.ac.uk/Risks/31/18 plus mentions of Boeing's issues above. "On 6 Apr 6, something known as the GPS rollover, a cousin to the dreaded Y2K bug, mostly came and went, as businesses and government agencies around the world heeded warnings and made software or hardware updates in advance. But in New York, something went wrong—and city officials seem to not want anyone to know. At 07:59pm EDT on Saturday, the New York City Wireless Network, or NYCWiN, went dark, waylaying numerous city tasks and functions, including the collection and transmission of information from some Police Department license plate readers. The shutdown also interrupted the ability of the Department of Transportation to program traffic lights, and prevented agencies such as the sanitation and parks departments to stay connected with far-flung offices and work sites." https://www.nytimes.com/2019/04/10/nyregion/nyc-gps-wireless.html "Many of the world's older GPS devices had a Y2K moment on 6 April. Devices made more than 10 years ago had a finite amount of storage for their date accounting system, and that number maxed out on Saturday, 6 April. Nineteen National Oceanic and Atmospheric Administration (NOAA) coastal and marine automated stations were not updated to mitigate the issue, and those stations are out of commission until workers can service them on location. The outage has the National Weather Service (NWS) office in Anchorage, Alaska, hurrying to fix their downed stations before bad weather comes in this week." https://eos.org/articles/noaa-monitoring-stations-are-off-line-from-a-gps-y2... Previous articles http://catless.ncl.ac.uk/Risks/search?query=GPS+rollover including 22.94 2003 Oct The Earth's not slowing down fast enough to suit Motorola (Paul Eggert) http://catless.ncl.ac.uk/Risks/22/94#subj3 illustrating 256 week offset and leap second problems. Risks Digest issue 17.86 1996 Mar has many articles related to leaps in time http://catless.ncl.ac.uk/Risks/17.86.html#subj9 -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised.
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