787's with GPS rollover issue grounded
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787's with GPS rollover issue grounded
Honeywell provides the flight management and navigation software for the Boeing 777 and 787. The company issued two service information letters in March warning of the GPS week-counter rollover and providing technical support data.
You found two operators that proved my point...
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However, EASA said, tests of some GPS devices revealed that not all manufacturer implementations will correctly handle the April 6 rollover. The EASA bulletin is intended to help operators understand the implications of the week-number rollover and recommend steps to rectify the issue.
https://ad.easa.europa.eu/ad/2019-01R1
So far, the only reported issues have been with Honeywell GPS systems...so far.
Add: BOM weather balloons grounded due to rollover. BOM said its equipment supplier advised the bureau of the fault after the rollover on April 7, and balloon launches ceased on April 8.
A Shanghai Airlines 787 was also reportedly affected.
https://ad.easa.europa.eu/ad/2019-01R1
So far, the only reported issues have been with Honeywell GPS systems...so far.
Add: BOM weather balloons grounded due to rollover. BOM said its equipment supplier advised the bureau of the fault after the rollover on April 7, and balloon launches ceased on April 8.
A Shanghai Airlines 787 was also reportedly affected.
Last edited by Smythe; 12th Apr 2019 at 04:24.
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https://www.flightradar24.com/data/aircraft/b-1113
Sounds like fake news that is based on a single tweet. The tweet (and article linked to above) include a photo from an aircraft with tail number B-1113. The same aircraft has been operating flights every day this month...
https://www.flightradar24.com/data/aircraft/b-1113
https://www.flightradar24.com/data/aircraft/b-1113
Presumably it takes rather less than 24 hours to accomplish.
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More like an early version of the Unix year 2038 rollover problem: https://en.wikipedia.org/wiki/Year_2038_problem
The Year 2038 problem relates to representing time in many digital systems as the number of seconds passed since 1 January 1970 and storing it as a signed 32-bit binary integer.
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More like an early version of the Unix year 2038 rollover problem: https://en.wikipedia.org/wiki/Year_2038_problem
The GPS standard has 10 bits of data for the date which is only enough for around 20 years. The last rollover was in 1999.
When unpatched GPS units rolled over to 000000000 on 8th April, the date showed as 1999. The Honeywell service bulletin below explains it well. The standard has now been updated to 14 bits of data so we won't have to worry about this again for a few hundred years.
https://aerospace.honeywell.com/en/news-listing/2019/march/service-information-letter-briefing-gps-week-rollover
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The CNAV GPS week number is now represented as 13 bits, or 8192 weeks, and only repeats every 157.0 years, meaning the next return to zero won't occur until the year 2137
Interesting that the 787 has issues with this. GPS rollover was basically fixed the last time it happened in 1999
ooops:
At 7:59 p.m. E.D.T. 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 from staying connected with far-flung offices and work sites.
The culprit was a long-anticipated calendar reset of the centralized Global Positioning System, which connects to devices and computer networks around the world.
Interesting that the 787 has issues with this. GPS rollover was basically fixed the last time it happened in 1999
ooops:
At 7:59 p.m. E.D.T. 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 from staying connected with far-flung offices and work sites.
The culprit was a long-anticipated calendar reset of the centralized Global Positioning System, which connects to devices and computer networks around the world.
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Meanwhile my 20+ year old Garmin portable powered up with the correct position and date on the morning after the rollover.
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The reason the aircraft are grounded due to this problem is there a risk that if for any reason the GPS system had to be rebooted during flight it would take the GPS an excessively long time to get a first fix and come online.
https://en.m.wikipedia.org/wiki/Time_to_first_fix
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So what's your working theory here, that the articles about the 787's not making the switch as well an the picture of the PFD with the date of 1999 are all fake?
