Lysander Ack Ack Spotters ww2

Hello Everyone, new entrant.
I’ve been looking for information on Lysanders based in N Ireland that carried Artillery Spotters over Liverpool, Cardiff, Bristol etc during air raids, presumably to confirm height of bombers.
My Father was based in N Ireland for a time,either with the Black Watch or on attatchment from Artillery and part of his job was to act as an airborne observer during raids over the three cities mentioned, maybe others.
Does anyone have any information on these units, I know Ballykelly was mentioned, but he could have flown from other stations.
I know some of the pilots were only about 19 years old because on one trip they ran out of fuel near RAF Locking and landed in a field and the age of the pilot was mentioned. My Father chose to go back to N Ireland by train and boat!!