Engines
Very unusual for a civil servant to be referred to as a Wg Cdr, though.
These "civil servants" were in what used to be called RO (Retired Officer) posts, which subsequently became MSF (Military Support Function).
They often - although not always -
were retired officers, although not necessarily in the rank they now "wore". They would have been granted a Reserve Commission of some sort, but were paid as Civil Servants. Complicated, no?