Acting pilot officer

Acting pilot officer (APO) is the lowest commissioned grade in the Royal Air Force, being immediately junior to pilot officer. Unlike other RAF ranks which officers may hold in an acting capacity, acting pilot officer is maintained as a separate grade. It normally denotes an officer who has recently been commissioned and joined as a non-graduate direct entrant. Acting pilot officer is not an actual rank, and APOs are later regraded to pilot officer, not promoted.

Although acting pilot officer has a NATO ranking code of OF-1, neither the British Army, Royal Marines nor Royal Navy has an exactly equivalent rank. As acting pilot officers are junior to second lieutenants in the British Army or the Royal Marines and to Royal Navy sub-lieutenants, the rank is the most junior commissioned rank in the British Armed Forces.

Senior cadets on a University Air Squadron may become acting pilot officers.

The rank insignia is identical to that of a pilot officer, consisting of a thin blue band on slightly wider black band. This is worn on both the lower sleeves of the tunic or on the shoulders of the flying suit or the casual uniform.