Throughout August, small numbers of U.S. aircraft and their crews continued to arrive at Guadalcanal. By the end of August, 64 aircraft of various types were stationed at Henderson Field. On 3 September, the commander of the 1st Marine Aircraft Wing, U.S. Marine Brigadier General Roy S. Geiger, arrived with his staff and took command of all air operations at Henderson Field. Air battles between the Allied aircraft at Henderson and Japanese bombers and fighters from Rabaul continued almost daily. Between 26 August and 5 September, the U.S. lost about 15 aircraft to the Japanese's approximately 19 . More than half of the U.S. aircrews shot down were rescued, while most of the Japanese aircrews were not recovered. The eight-hour round-trip flight from Rabaul to Guadalcanal, about , seriously hampered Japanese efforts to establish air superiority over Henderson Field. Australian coastwatchers on Bougainville and New Georgia islands were often able to provide the Allied forces on Guadalcanal with advance notice of inbound Japanese air strikes, allowing the U.S. fighters time to take off and position themselves to attack the Japanese aircraft as they approached the island. The Japanese air forces were slowly losing a war of attrition in the skies above Guadalcanal.