'Balsam' (ii) was a British naval programme of carrierborne photo-reconnaissance and attack missions flown in preparation for 'Zipper' and other operations planned for this period against the Japanese occupying forces in Malaya and the Netherlands East Indies (18/20 June 1945).
The ships of Force 63 involved in this undertaking were the escort carriers Ameer, Khedive and Stalker, heavy cruiser Suffolk, light anti-aircraft cruiser Royalist, and destroyers Racehorse, Redoubt, Relentless, Roebuck and Rotherham.
The ships of Force 63 departed Trincomalee in Ceylon on 14 June, and from flying off position in the northern approaches to the Strait of Malacca, Grumman Hellcat aircraft of No. 888 Squadron in Ameer made successful photo-reconnaissance flights over the southern parts of Malaya on 18, 19 and 20 June.
Fighter-bomber attacks against the airfields at Lhoksemawe, Medan and Binjai were made on 20 June by Supermarine Seafire aircraft of No. 809 Squadron and Hellcat aircraft of Nos 804 and 808 Squadrons. Runways at Medan and Binjai were put out of action with 500-lb (227-kg) bombs, and attacks against aircraft on the ground resulted in three being destroyed, seven left burning and probably destroyed, and nine damaged. Airfield buildings, locomotives and rolling stock were also strafed, and off Medan two junks, one of them carrying oil, were attacked and set on fire.
The British losses were just one Hellcat shot down by anti-aircraft fire. Force 63 was apparently not detected throughout its operation.