I am looking to permanently disable WiFi on my Macbook Air

Removing any kext (driver) files from the Mac's System or Library folders is a bad idea which could lead to kernel panics or your notebook not booting up requiring a complete reinstall of macOS.

However, if you are adamant about disabling Wi-Fi, all MacBook Air models include a combo AirPort/Bluetooth card/motherboard that can be removed. However, doing so will also disable Bluetooth and potentially void any warranties for the notebook.

If you go to System Preferences > Networks, have you looked into turning everything off there?

FWIW, one of the advantages of a good laptop is to provide easy connections to WiFi, so you can turn off your router/modem which is how you connect to the internet.

One of the outcomes from messing with an integrated device hardware to disable portions

later occurs when someone tries to renew an otherwise easily turned off/on feature; missing.

My portables have simply and easily been run from Ethernet and by wire from the cable

or from ADSL etc; the settings are configured and cannot re-activate themselves. And the

desktop Macs as well; I use wi-fi from my local AirPort express & options for two channels.

The System Preference controls are easily configured to allow/disallow secure features here.

To muck around in hardware to permanently disable a feature disallows helpful troubleshooting

once the wi-fi is decapitated from within. Default abilities to restore via Recovery can take a hit.

(Glad this isn't common place idea; repair shops could also generate troubleshooting revenue, too.)

So this is a rather primitive trail to follow. Not unlike 'forceful plug-pulling' to shutdown desktops. 🌞

Seems a little extreme... Why not just turn it off and leave it off?

We are not allowed to post live links to this, so you will need to copy/paste (and add the www.):

ifixit.com/Search?doctype=post&query=remove%20macbook%20air%20wifi%20

Thanks! I couldn't agree more. This reminds me of a "solution" to prevent remote hacking a server ... and that was to physically disconnect it from the network. It worked, as no one could hack it from a remote location ... but it definitely was not a "solution."

Looks like babowa got back to you before I could ...

@babowa - Thanks for providing the OP the link.

No problem (and they do remove live links to that site).

Surgical removal of Wi-Fi seems bit extreme, you must not like it very much. 😎