Transom was the second of two raids—Operation Cockpit being the first—that marked the first big offensive raids by the British Fleet Air Arm in the Far East. The Royal Navy was building the British Pacific Fleet, its naval strength in the Indian Ocean, in preparation for joining the war in the Pacific. Transom provided experience in naval air raids and replenishment at sea. Aeroplanes from the aircraft carrier also took part in the raids on Sumatra and Java, after a joint training exercise with the British ships. Surabaya was the centre of Japanese anti-submarine operations for the region. And a major oil facility was nearby, at Wonokromo. It was a difficult target: Deep within enemy territory on the other side of Java island. Aircraft had to fly 180 miles - partly over mountainous terrain - to reach the target. Task Force 66 arrived at its launch position about 180 miles south of Java at 04.30 on May 17. The weather was fine with a few scattered clouds and a light southeasterly wind. Force A was to hit the Wonokromo oil refinery facilities. Nine FAA Avengers were to hit the Braat Engineering Works with their loads of four 500lbs General Purpose Bombs. Twelve of Saratoga’s Dauntless were ordered to attack the oil tanks. Escort was eight FAA Corsairs. Force B was to bomb the Surabaya harbour. Six FAA Avengers were directed towards the naval workshops, while another three were to attack a floating dock. Once again, the bombers would carry four 500lbs bombs each. Eight Corsairs formed the designated close escort. Accompanying this force was to be six of Saratoga’s Dauntless dive bombers, each hefting a 1000lbs bomb. Their job was to attack a cruiser that had been reported in the harbor, as well as floating docks and harbor facilities. Twelve of Saratoga’s Avengers were tasked with attacking merchant shipping and commercial harbor facilities. Close escort was 12 Hellcats. No Japanese aircraft were encountered, and anti-aircraft fire was ineffectual. Bombs were dropped on the harbor, warehouses and oil facility. All were seen to be burning fiercely. At the nearby Japanese airfields, 12 aircraft were caught on the ground. The FAA's raid on the Wonokromo oil refinery was effective, leaving it completely burnt-out. One ship was sunk in the docks and the harbour facilities hit. The raid was deemed a qualified success. One Avenger, from Saratoga, was shot down. The crew was observed to have entered a life raft, but was never seen again. Seven land-based B-24 heavy bombers of the 380th Bombardment Group, U.S. Army Air Forces, made a follow-up night attack on Surabaya Harbor, from their base at Corunna Downs Airfield, in Western Australia.