In May 1943, Gibson, just promoted to acting squadron leader, attended a course at the Army Staff College at Linton Military Camp before resuming staff duties. In December, he rejoined No. 15 Squadron, at the time based on New Georgia in the Solomon Islands. He took over as its commander from Squadron Leader Michael Herrick. At the start of 1944, the squadron covered the landings at Bougainville, before commencing operations from the island itself. He destroyed a "Zeke", a variant of the Mitsubishi A6M Zero fighter, on 23 January during a mission escorting Grumman TBF Avenger divebombers over Rabaul. The next month, the squadron went to New Zealand for a rest. It returned to the South Pacific for another operational tour, flying first from Guadalcanal and then Bougainville. In August, Gibson's secondment to the RNZAF ended and he returned to Europe soon afterwards. His rank of squadron leader had been confirmed the previous month.