Well spotted. Yes, he was in the RNAS. I have his wings - presumably the ones in the picture.
One of the lucky WWI pilots. He survived the nearly 50% training-fatality rate and then, in November 1918, before becoming operational, he was in hospital, fighting the Spanish Flu.
My other grandfather was also lucky. He survived a Camel crash and ended the war as a POW. I wrote up his fascinating story on the 100th anniversary of his crash:
https://www.pprune.org/aviationm-his...shot-down.html
My parents met when both families were on holiday in Clacton in the late 30s. I have always presumed that both fathers approved of the match because of their mutual backgrounds.