1939 Register - Annotations and What They Mean?

[MaecW]

On the far right of the census pages the enumerators have noted if an individual had potential war-time responsibilities such ARP or WVS. Most of these are easy to translate but one on a (potential) family member has got me puzzled. These are the letters "N.A.C.".  The man is an "aviator/pilot" but not given as RAF or either of its reserves. Could it be a branch of the Navy's Fleet Air Arm or some sort of goverment civilian unit ?
All idea welcome !

Maec

[sarah]

Hello Maec,

I have just moved your topic to the armed forces section

Sarah

[ShaunJ]

National Air Communications.

See https://en.wikipedia.org/wiki/National_Air_Communications

[MaecW]

Thank you, Sarah, for moving this enquiry.

And thank you Shaun. That will be it. My man was resident in Penzance so probably with Great Western & Southern Air Lines Ltd operating from Lands End. I can investigate further 

Maec