American bombers yesterday struck their second major blow in two days at Germany's war industry and carried the Allies' heaviest air offensive of the war into its 72nd hour.
    Brunswick, 120 miles west of Berlin, was sledge-hammered by a force of Fortresses and Liberators almost as great as the record fleet of more than 800 heavy U.S. bombers which in daylight Saturday dumped a record 1,800 tons of high explosives and incendiaries onto Frankfurt, in the southwestern Reich.
    The two American attacks, bringing the USAAF's total for the month to ten, were coupled with two successive RAF raids on Berlin, stretching the Nazis' overworked defenses toward the breaking point. The great assaults by the heavies were supplemented by endless relays of Allied medium, light and fighter-bomber assaults on other targets in Nazi-occupied Europe.

    The report on the Brunswick attack referred for the first time in a communique to the new administrative setup of the USAAF in the ETO -- the U.S. Strategic Air Force in Europe -- official name for the heavy bombers whose task probably will continue to be the disruption of Germany's war manufacturing and transport machine behind the invasion walls.
    Yesterday's raid, like Saturday's, involved a round trip of about 900 miles. It was the second U.S. blow at Brunswick, which first was hit by the Americans in the widespread attacks of Jan. 11, when 60 bombers were lost in successful attacks on aircraft factories throughout central Germany.
    In the attack on Brunswick, Capt. Walker Mahurin, of Fort Wayne, Ind., leading ETO ace, boosted his total to 15 by shooting down a Ju88, and Maj. Walter C. Beckham, of DeFuniak Springs, Fla., second high scorer in the ETO, got an Me109, bringing his total to 14.
    A Lawton, Okla, Thunderbolt pilot, 1/Lt. Robert S. Johnson, shot down two -- an Me210 and an Me109 -- to tie Maj. Beckham for ETO second place with 14 destroyed Germans to date.
    Brunswick is the site of factories turning out complete bomber and fighter units, as well as components for virtually all the Luftwaffe's machines. The Brunswick-Waggun plant making Me110 assemblies, severely damaged in the Jan. 11 attack, is one of the largest of a group including the Muhlenbau U. Industrie E.G., making fighter-bombers and trainer components, the Brunswick-Neupetriter plant, the Niederfachsische Motor Enwerg at Brunswick Querun, and other assembly factories. The city also was hit by the RAF on Jan. 14, when 2,200 tons spread devastation in a night attack.
    The USAAF fighters escorting the bombers were taking up their second major battle in two days. They set a new record for enemy aircraft destroyed in Saturday's assault, shooting down 42 confirmed victims for the loss of 13, while the heavy-bomber gunners were destroying 60 enemy aircraft for the loss of 31 U.S. bombers.
    While the heavies were flying against Brunswick, the German High Command issued a communique admitting "heavy damage" in the attacks on Frankfurt.
    The attack on Frankfurt was being prepared even as Liberator groups were coming home from Friday's "milk run" attack on military installations in northern France. Bombed-up and briefed early, the heavy bombers were winging out to Frankfurt only a little while after RAF Lancasters came back from Berlin.
    As the biggest force of American heavy bombers ever to fly a combat mission swung over the German coastline and headed for the industrial metropolis on the Main, 900 miles airline round trip from London, the Luftwaffe threw up major formations of interceptors.
    Using tactics which apparently have become standard practice in the last two months, the Nazi fighters and rocket planes concentrated almost their entire attack against single groups and elements of the bombers, which apparently accounted for varying combat reports after the crews came home. Some groups met intense fighter opposition, as well as heavy flak; others had only the flak to bother them as the USAAF fighters kept off stray Luftwaffe interceptors.
    As they approached the target some groups had to battle through head-on attacks not only by standard fighters but by rocket-firing craft, which usually stay well out at long range.
    In Frankfurt, chief railway junction for western Germany, some 500,000 persons are engaged directly or indirectly in transportation, in manufacturing chemical and machine tools for the Wehrmacht and in the distribution of supplies which funnel into the city's inland port at the juncture of the Main and Rhine rivers. Prime target of the manufacturing communities in and around the city was a suburban plant turning out possibly half of the propellers used by the Luftwaffe.
    Thunderbolt and Lightning fighter groups and long-range Mustangs escorted the Fortresses and Liberators in relays to the target and on the way home. More relays of USAAF fighters carried them back to within range of Allied Spitfire escorts.
    While the heavies were hitting Frankfurt, Marauder mediums carried on the pounding of the military installations in the Pas de Calais area. The B26s now have flown 1,500 sorties with the loss of only three planes. Saturday's was their eighth attack of the month.

    The second major force of American bombers to strike the Reich in two days yesterday pushed deep into central Germany to bomb the already battered aircraft-manufacturing center of Brunswick.
    The attack, covered all the way to the target and back by relays of American fighters, came before the Nazi defenses had recovered from the biggest daylight raid in history -- Saturday's assault by more then 800 Fortresses and Liberators on the railway and manufacturing city of Frankfurt, in southwest Germany.
    Bombing through clouds, yesterday's force flew in an overcast haze, through which German fighters slashed in desperate efforts to halt the aerial armada. Almost as many planes were in the attacking force, it was estimated, as in Saturday's 1,800-ton assault, which included more than 700 fighters.
    At a late hour last night USAAF headquarters had not announced the losses.
    German radio said at least 53 planes were shot down, 41 of them four-engined bombers. "Despite bad weather conditions," the German News Agency said, "the German air defense has been able to inflict another smashing blow at the American bombers which attacked southwest German territory."