I was at the old Limavady Airfield and have photographed the sign shown here.

It is painted on the wall of a corridor inside a Maintenance Unit building.

This may date from the 1950’s but not sure.

The top wording appears to say “O.C. R.A.I.” while the lower one is “NCO i/c 8172” which may be Fleet Air Arm.

Can anyone identify what this means for me please??