How to disable the wireless / airplane mode Fn key?
Solution 1:
If he doesn't need to use F2, just pop the key off, put some sponge rubber or resilient foam plastic under the key, sized to make it difficult, but not too difficult to press the key, and replace the key cap. On a laptop, it may be easier to gently push the foam plastic under the edge of the key using a fine screwdriver blade, being careful not to puncture the membrane below the key.
On my keyboards, I also do this for Caps Lock, to avoid accidental SHOUTING.