On 27 October, Task Force 38 provided air cover for the invasion of the Treasury Islands, part of the preliminary operations for the invasion of Bougainville Island scheduled a few days later. On the morning of 1 November, "Saratoga"s aircraft neutralized Japanese airfields at the northern end of the island and on Buka Island. They destroyed 15 Japanese aircraft while losing three Hellcats, one Dauntless, and two Avengers to all causes. While the task force was refuelling on 3–4 November, reconnaissance aircraft discovered Japanese cruisers massing at Rabaul and Admiral Halsey ordered Task Force 38 to attack them with maximal force before they could engage the transports at Bougainville. This translated into an attack group of 23 Avengers and 22 Dauntlesses, escorted by every available fighter on board the two carriers on 5 November; CAP over the carriers was provided by fighters flying from New Georgia. The attack caught the Japanese by surprise and badly damaged four heavy cruisers, two light cruisers, and a destroyer for the loss of only nine aircraft to all causes.