There are also gaps in the history ("no data available") of the permanent code, like: https://globe.adsbexchange.com/?icao=a835af&lat=34.765&lon=-98.635&zoom=3

There are also gaps in the history ("no data available") of the permanent code, like: https://globe.adsbexchange.com/?icao=a835af&lat=34.765&lon=-98.635&zoom=3.0&showTrace=2022-12-12 https://globe.adsbexchange.com/?icao=a835af&lat=34.765&lon=-... Couldn't they have used the PIA code on those days?