Hello gang, we are operating some aircraft equipped with a triple LTN 92 configuration. Our Operations Specifications show a RNP degradation from 5 to 10 after past 2 hours since the last DME update. In an scenario where we are going across the Atlantic, am I required to be back on a RNP 5 status just prior to enter european airspace? I understand that as soon as I receive an update, I go back from RNP 10 to RNP 5, but is there a requirement to remain RNP 5 compliant while flying across the Atlantic? Or perhaps a set boundary in the european airpace by which we must comply with? As you know there will be a point where the two hours from the last update will have expired. I did many crossings with these units and this was never an issue, but now it seems to be one...
Thanks

This is where I found some info back in the years when I used to cross the Atlantic on a 707 with three Litton 72's: NAT PCO

Have fun