Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Nomad63
#1676223
April 16th
A problem for something like Garmin 496?, or would it have to be really ancient gear to fail to adjust itself?
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By alexbrett2
#1676225
I've found a couple of bits of information on this from Avionics manufacturers specifically:

Garmin
They say no problems (https://www.garmin.com/en-US/aviational ... -rollover/), but they don't explicitly list which units have been tested so while I'd imagine GNSx30 and GTN series units are fine, it's unclear what this means for really old devices.

Avidyne
IFD units will display an incorrect date and indicate databases out of date, but otherwise function. There is an update which resolves it, and you can get it as a UK based pilot, and it's a simple enough install (for CofA aircraft it is unclear if as a pilot/owner you can legally install it yourself, so I suggest talk to your CAMO) - see http://forums.avidyne.com/are-our-ifd-u ... c1675.html or http://www.avidyne.com/files/downloads/ ... 82-019.pdf for more details...
Last edited by alexbrett2 on Mon Feb 18, 2019 10:17 pm, edited 1 time in total.
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By neilmurg
#1676229
Is this the millennium bug again? Time to remind ourselves of the leap year calc. every year divisible by 4 EXCEPT years divisible by 100 UNLESS divisible by 400.
(So, 1900 wasn't 2000 was, 2100 won't be).
Oh and the Unix 32 bit date rollover, 2038 etc etc
btw a working garmin link here
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By PaulB
#1676234
How will this affect iPads and Android devices (as well as third party GPS's in things like SkyEcho & PAW)?
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By Dave W
#1676235
"GPS dates are expressed as a week number and a day-of-week number, with the week number transmitted as a ten-bit value. This means that every 1024 weeks (about 19.6 years) after Sunday 6 January 1980 (the GPS epoch), the date resets again to that date; this happened for the first time at 23:59:47 on Saturday 21 August 1999 and will happen again at 23:59:42 on 6 April 2019 and on 20 November 2038. To address this concern, modernised GPS navigation messages use a 13-bit field, which only repeats every 8,192 weeks (157 years), and will not return to zero until near the year 2137."

My bold.
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By GolfHotel
#1676246
I’ve done the update on the ifd440. Took about the same time as reading this thread.

Now I’ve gone on to worrying about 2100 not being a leap year. Not sure how I’m going to cope with that.

And BTW why wasn’t the test for the millennium to be divisible by 4000 not 400. I think someone stole a day off me. I want it back.
Flyin'Dutch', Iceman liked this
By NDB_hold
#1676279
Actual length of a year approx 365.2422 days
Old (Julian) calendar year was 365.2500
New (Gregorian) calendar year is 365.2425 - if you think about it.
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By stevelup
#1676289
PaulB wrote:How will this affect iPads and Android devices (as well as third party GPS's in things like SkyEcho & PAW)?


Doubtful that any kit made in the last few years will be affected. That said, how Avidyne managed to mess it up is anyone's guess...
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By Trent772
#1676295
Slight thread drift but amusing.

A multi million pound Airbus can't cope with February !

Certain P/N aircraft clocks go nutty in February if slaved to the GPS and have to be selected to internal time for the month.

:mrgreen:
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By neilmurg
#1676306
NDB_hold wrote:Actual length of a year approx 365.2422 days
Old (Julian) calendar year was 365.2500
New (Gregorian) calendar year is 365.2425 - if you think about it.
I don't think the orbit of the earth completely stable/repeatable... Weren't there efforts last year to do away with leap seconds which are occasionally added (taken away?). The difference of 0.0003 is approx 26 seconds.
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By T67M
#1676324
stevelup wrote:
PaulB wrote:How will this affect iPads and Android devices (as well as third party GPS's in things like SkyEcho & PAW)?


Doubtful that any kit made in the last few years will be affected. That said, how Avidyne managed to mess it up is anyone's guess...


Your confidence is, sadly, misplaced. I'm doing a lot of work on the GPS rollover at the moment, and a large number of systems, from multiple manufacturers, some only released in the last six months, are having emergency fixes applied to them because, when tested, they fail - and not always on April 6th. This is because following the first. WNRO (Week Number Roll Over) event in August 1999, many manufacturers simply coded in a fixed offset giving them 19.7 years from the date of manufacture.

GPS WNRO#2 looks like it's the gift that will keep in giving for the next two decades :wall:
By riverrock
#1676329
Indeed - my new car's built in TomTom satnav (bought less than a month ago) requires a software update to continue working after April. I suspect many other cars are the same.
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