The Allied aerial onslaught against Germany gave every indication yesterday of rising to a new peak of fury during October as the Air Ministry announced that RAF heavy bombers had struck in force at Frankfurt less than 12 hours after American Flying Fortresses had delivered their precision blow on the big war production center Monday.
    Large fires were left burning in the city as the heavy bombers turned homeward early yesterday morning. It was the RAF's first blow at Frankfurt in which more than 500 tons of bombs were dropped.
    While the main attack was going on, a force of Lancasters bombed Ludwigshaven and Mosquitoes attacked other objectives in northwest Germany.

    The one-two punch of the combined Anglo-American air might left no doubt in German minds that the great winter air offensive against Germany was on.
    In the last eight days 11 major raids have been carried out against the Nazis' production centers, with an intensity of bombing never previously seen.
    Meanwhile, the Eighth Air Force announced yesterday that the Forts' blow at Frankfurt -- aimed principally at the Germans' largest metal aircraft propeller plant, in a suburb of the city -- had been carried out with the lowest loss ratio to date, on a deep penetration of Germany.
    Fifteen heavy bombers were lost in the day's operation, which included Fortress blows at other targets in the city and in western Germany, and a diversionary feint of Liberators over the North Sea to lure Nazi fighters away from the Frankfurt raiders.

    The Libs were successful, headquarters said, in raising a swarm of enemy fighters, a number of which were destroyed in "repeated and reckless" attacks on the Libs. So furious were the battles over the North Sea that one Me109 rammed a Liberator, both planes going down.
    In the day's operations, the heavies shot down 56 Nazi fighters and escorting Thunderbolts got 19.
    Stockholm reports yesterday said that after the Forts left, 64 streets in Frankfurt were unusable, 3,000 houses destroyed or almost destroyed, and gas, water, electricity and telephone services not functioning. Direct hits were made on numerous factories, including the I.G. Farben concern and the Adler, Opel and Bosch works, while the main railway station was partly destroyed by fire.
    The town's defenses were taken by surprise in yesterday's daylight raid, a correspondent said. Fire fighting services were inadequate, many of the firemen having been called up to help fight the fires at Kassel.
    The V DM propeller plant, which the Forts struck near Frankfurt, forges and machines a considerable percentage of all propellers used by German aircraft. The modern plant also makes other aircraft components. It is believed to employ approximately 10,000 workers.
    Two large railway yards and huge railroad shops manufacturing locomotives and freight and passenger cars make this city of 500,000 people the most important rail center in the middle Rhine Valley. Located near the juncture of the Main and Rhine Rivers, it is also an inland port of importance, and the foremost distributing center of southwest Germany. Highly industrialized, the city contains aircraft component factories and chemical and machine industries of prime importance.
    The Forts found the weather clear over Frankfurt, and despite intensity of fighter opposition, the bombardiers had good bombing runs. Results were described as good.
    One formation of Forts was led by Col. Bud J. Peaslee, of Santa Cruz, Cal. He said: "The attack was an outstanding demonstration of team-work between bomber formations and friendly fighter escort. I cannot praise too highly the performances of our American P47s and the English Spitfires. They covered us perfectly during our penetration and withdrawal from Germany. At the target the weather was perfect for our bombardiers, and for the German fighters, who gave us a warm reception."