Japan attempted to replace their lost air crews in 1943. Unfortunately for the Japanese, these reconstituted carrier air groups were put ashore at Rabaul in November 1943 in an effort to counter US moves into the upper Solomons and Bismarck Archipelago. Though they performed reasonably well, they suffered further losses in the air battles over Rabaul. Further reformation and training followed, and they were not ready to challenge the US Navy in a major carrier engagement until mid-1944.