PEARL HARBOR -- The destruction of 300 enemy planes in a furious aerial engagement over the Marianas revealed today that powerful American and Japanese task forces were prowling the Pacific within virtual battle range and may clash in the first test of major fleet units in nearly two years.
(A Japanese communique acknowledged the landing on Saipan and said the Americans steadily were reinforcing its ground troops. The Japanese said their planes continuously were attacking the powerful American task force which supported the landing, and since June 12 had sunk six United States warships, including one battleship, damaged seventeen others and shot down, more than 300 planes).
(Another enemy communique, broadcast by Tokyo radio to Japanese areas and reported by FCC monitors, admitted the Japanese suffered "considerable losses in ships and planes" off Saipan).
Naval planes and warship guns brought down the record bag of Japanese aircraft Sunday as American troops captured Aslito, airdrome, only four hours' flying time from Tokyo, and conquered more than one-third of Saipan, from the west coast beachhead to Magicienne bay in the east.
Greatest Single Bag.
Although American losses were not yet available, beyond the announcement of minor damage to one surface ship, the destruction of at least 300 Japanese planes was the greatest number ever shot down in a single aerial engagement in the Pacific. More than 300 enemy planes probably were lost in the battle of Midway, but many went down with wrecked Japanese aircraft carriers .
From the size of the Japanese aerial fleet, apparently aiming a major blow on the United States Saipan beachhead, the enemy must have had a sizeable task force, including carriers, the usual escorting cruisers and destroyers, and possibly battleships.
Similarly, the strength of the American force was indicated by the fact it was able to throw up enough planes and a sufficient heavy anti-aircraft barrage to prevent damage to all but one ship.
Japs Likely Fled.
With a good proportion of the Japanese task force planes apparently destroyed, the virtually undamaged American fleet probably would have sought to close with the enemy unless the air battle was fought so late in the day that the Japanese were able to flee in the darkness.
The crushing blow to the Japanese aerial forces came almost simultaneously with the American land strikes across southern Saipan, where Seabee construction crews already were working on Aslito airdrome and its 3,600-foot runway, which if extended, was believed large enough to accommodate the new B-29 Super-Fortresses.
Veteran marine and army troops carried the advance through Saipan to gain control of the western shore of Magicienne bay, cutting off the southeastern tip of the island above Nafutan point and leaving only small enemy pockets east of Lake Susupe near the Charan Kanoa area.
Size of U. S. Force.
(The Japanese Domei news agency said the landing last week was carried out by nearly 20,000 United States troops and estimated that reinforcements since then had boosted the American force to at least two divisions, approximately 30,000 men).
Adm. Chester W. Nimitz' communique, which gave no further reports of the spearhead thrusting at the island's capital of Garapan, indicated that the newly captured Aslito airdrome soon will be ready to support future ground operations or fleet actions similar to Sunday's battle.