Momote airfield was found to have been constructed on a coral subbase with an overburden of coconut palm humus, over which the Japanese had laid a thin layer of coral and coral sand. This would not withstand heavy use, so 40th Naval Construction Battalion, 8th Engineer Squadron, and Shore Battalion of the 592nd EBSR had to strip away the humus and lay a new coral surface. Just of runway was sufficient for the Kittyhawks and Spitfires but the runway was increased to by late April. B-24s of 5th Bombardment Group moved in on 18 April 1944 and flew their first mission, against Woleai two days later.