Decode of NAT Track Message
 

Hi there,


I'm curious about North Atlantic Ops and was reading up on the NAT Track Message. Can anyone help with this decode? TZA179 082009
FF BIRDZQZZ BIKFYXYX
082009 EGGXZOZX
(NAT-1/3 TRACKS FLS 310/390 INCLUSIVE
APR 09/1130Z TO APR 09/1900Z
PART ONE OF THREE PARTS-
A ERAKA 60/20 62/30 63/40 63/50 MAXAR
EAST LVLS NIL
WEST LVLS 310 320 330 350 360
EUR RTS WEST ETSOM
NAR -
What does those in bold refer to?

Thank you

TZA179 is the transmission ID. FF means this is a flight safety message. The eight letter bits are airfields/centres and their types: BIKF (Keflavik) is a military airfield (YXY) and the trailing X just completes the format. EGGX is Shanwick and it is an Oceanic Centre (ZOZ). Similarly, BIRD is Reykyavik FIR (ZQZ). I suspect the trailing Z should be an X? ZQZX makes sense. The numbers are a date/time group.

If your interested, theres a bit more info on the formating of AFTN;

https://en.wikipedia.org/wiki/Aerona...cation_Network