A quick way to get in a lot of trouble in the US Nuclear Navy was to bring your TLD onboard a flight.
If I understand correctly, you're saying a single commercial flight is enough to trip the dosimeter?
A single full body CT of radiation every year for that flight crew.
Source: wore one of these daily for years and would get regular reminders not to bring them on flights or anywhere else they would have to go through an xray machine (eg some federal buildings)