"Phoenix" escorted the United States Army Transport and the Australian transports and , which had been substituted for the withdrawn "Mariposa", as convoy MS.5 leaving Melbourne 12 February for Fremantle and ultimately bound for Colombo, Ceylon with troops and supplies destined for India. At Fremantle the aircraft carrier and merchant vessel joined the convoy with a 22 February departure for Colombo. Of particular note in the cargo of the convoy and specifically that of "Langley" and "Sea Witch" were P-40 aircraft, originally intended for the Philippines, that had been delivered to Australia earlier by "Mariposa" and "President Coolidge" in the convoy escorted by "Phoenix" from San Francisco. The plan had been that on relief of "Phoenix" by a British cruiser in the vicinity of Cocos Island she would escort "Langley" and "Sea Witch" to Java. Instead "Langley" and "Sea Witch" were destined to break with the convoy for Tjilatjap, Java under orders from Admiral Helfrich received the day after departure from Fremantle and proceed independently to deliver their aircraft. "Langley" was attacked and sunk on 27 February. "Sea Witch" successfully made delivery on 28 February just as the results of the Battle of the Java Sea had sealed the fate of the islands. The crated planes delivered were destroyed before assembly to deny them to the enemy. "Phoenix" turned over escort of the Colombo bound ships about 300 miles west of Cocos Island to on 28 February and returned to Fremantle on 5 March 1942.