NTP question

Mel Beckman mel at beckman.org
Thu May 2 03:30:03 UTC 2019

Yo Gary!

Not only did I not sleep through it, I was one of the engineers who verified that every GPS clock source in a very large aviation support network didn’t have have this bug. 

I’m also an FAA licensed A&P mechanic, and have worked for airlines in fleet maintenance.  Air carriers have extremely thorough systems reviews, by law, through the Airworthiness Directive program, which started identifying 2019 GPS rollover vulnerabilities in ... 2009! Nobody was surprised.  If any GPS systems “went nuts”, it was through the incompetence and negligence of their owners.


> On May 1, 2019, at 8:03 PM, Gary E. Miller <gem at rellim.com> wrote:
> Yo Mel!
> On Thu, 2 May 2019 02:54:25 +0000
> Mel Beckman <mel at beckman.org> wrote:
>> Why? The GPS NTP Server is Stratum-1.  If it fails computer clocks
>> will freewheel for hours or days before losing significant time,
>> during which period you can simply order a replacement unit. If that
>> isn’t fast enough, buy two $300 boxes. The “consensus” issue is moot,
>> since a GPS server gets a consensus of clock time from the GPS
>> satellite constellation. 
> I guess you slept through GPS Week Roll Over day last April 6th?
> Some GPS went nuts, others did not.  Many 777 and 787 were grounded that
> weekend for software updates to their expensive Honeywell GPS.  I'll
> spare you the many more examples that hapened.
> Not nice when yoar clock rolls back to 1999, or forward to 2035.
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
>    gem at rellim.com  Tel:+1 541 382 8588
>        Veritas liberabit vos. -- Quid est veritas?
>    "If you can’t measure it, you can’t improve it." - Lord Kelvin

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