SAFETY NOTICE - GPS 2019 Week Rollover

The Global Positioning System ”GPS”, that provides accurate timing and tracking information to many of our critical systems – including aviation will have a timing issue by 2019.04.06 due to so called “Week RollOver”.

The Week Rollover issue is caused by the way that GPS uses the week element of the data, to form an essential part of the navigation signal. Historically went the GPS system live on 6 January 1980 and work with 1024 week frames meaning that the first epoch of GPS time lasted until 21 August 1999 and the end of the second “Roll-Over” will fall on the 6 April 2019 and the receivers reset to zero and starts counting again. 

The “Roll-Over” situation may or may not influence GPS based systems with changes in performance, capability and certification, actually issues may not necessarily incur on the actual date, but later and generally epending on equipment type, age, modifications etc. and all GPS users should be aware about 2019.04.06 and if it should be of relevance for their system and/or operation.

We are of course available with support and evaluation of navigation and other systems based on the GPS constellation. Contact us and please provide equipment part number, serial number, software, modification status as well aircraft type, registration and operational certification status.


Scandinavian Avionics provides complete turn-key avionics solutions for civil and military aircraft, helicopters and UAS. Including sales, avionics maintenance (MRO), certification (STC), design & engineering, installation, product development, production, training and consultancy services.

The SA Group consists of 11 divisions located in Europe, the Middle East, South- and Southeast Asia. The headquarters, which was established in 1978, is located in Billund, Denmark. 

EASA Part-145 | EASA Part-21J | EASA Part-21G | EASA Part-147 | FAA Part-145 | TCCA Part-145 | BCAA Part-145 | GAR Part-145 | DOT RIN N083

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