MBA randomly drops internet connection
It might be an incompatibility with your access point or issue with the driver. I had my driver crash several times, leaving the network stack unresponsive and requiring restart. This happened during a short power surge, leading to the router "almost" restarting (it's a Mikrotik router, the radio was down for a second, but not the whole router). Everything else reconnected (several iPhones, iPad and few other devices), but not my MacBook (at the time it was running 10.13 17A405)

Check your access point/router logs for a drop reason (if it provides any).

When this happens, you might do a wireless diagnostics report (option click on wifi icon, tap on ) and then search trough the files for some suspicious lines. After you collect several of them, open a bug report.

Another lead would be kernel based third party firewall solutions.