'Margin' (i) was a British bombing attack on Augsburg in Germany (17 April 1942).

The Allies made three major air assaults on Augsburg in World War II in the form of two British and one US raids, the first British raid on 17 April 1942 and the latter British and single US raids on 25/26 February 1944.

To take advantage of the capabilities of the new Avro Lancaster heavy bomber to achieve accurate bombing of a vital target using a small force of bombers operating at low altitude by day, Air Marshal A.T. Harris, the commander-in-chief of RAF Bomber Command, planned an experimental raid against a high-value target. Initial consideration was given to one of the ball bearing factories in Schweinfurt, but for tactical reasons Harris finally opted for the MAN factory in Augsburg as this produced Diesel engines for U-boats. This target was a long distance inside Germany, some 500 miles (805 km) from the French coast. A nocturnal attack would not currently have been able to provide the assurance of accuracy, so the plan was to attack by day and cross German-occupied territory and then Germany at low level.

The bomber force was drawn from No. 44 (Rhodesia) Squadron at RAF Waddington and No. 97 Squadron at RAF Woodhall Spa, each of which provided a flight of six aircraft which practised low-level flying for a week.

As 'Margin' (i) was launched, 30 Douglas Boston medium bombers and a large number of fighters of RAF Fighter Command effort were dispatched to targets in northern France in an attempt to draw off German fighters. One Boston was lost in these diversionary activities.

Flying at an altitude of only some 50 ft (15 m), the 'Margin' (i) bomber force crossed the English Channel and started to fly across northern France. The aircraft of No. 44 Squadron, under Squadron Leader J. D. Nettleton flew close to an airfield on which was based the fighters of Hauptmann Karl-Heinz Greisert’s II/Jagdgeschwader 2. Even as they were apporaching to land, several of the German fighters set off in pursuit and shot down four of the Lancaster bombers. No. 44 Squadron’s two remaining bombers continued and attacked the target with four 1,000-lb (454-kg) bombs each. One of the bombers was hit by Flak and crash-landed with the loss of three of the crew, and the last, flown by Nettleton, returned to base. No. 97 Squadron’s six bombers attacked shortly after Nettleton’s two machines in two sections of three. The first attacked at roof-top height, flying even lower after dropping their load to evade Flak on the way out, but one was hit, crashed and exploded. Of the last three aircraft, two were hit and caught fire. One exploded after completing the attack, but the others completed their attacks and were able to return to base at high altitude and under cover of darkness.

In the course of the raid, seven of the 12 Lancaster bombers had been shot down with the loss of 49 crewmen, of whom 37 were killed and 12 taken prisoner. Seven bombers were claimed by Hauptmann Walter Oesau (two), Feldwebel Otto Pohl (two), Feldwebel Alexander Bleymüller, Hauptmann Karl-Heinz Greisert and Feldwebel Ernst Bosseckert.

The operation had good propaganda value to the British public inasmuch as it showed that Bomber Command could reach targets in the far reaches of Germany, but Lord Selborne, the minister of economic warfare, was infuriated that the target was not one of those which had been specified by his ministry for attack.

Post-war analysis indicated the damage inflicted on the Germans was minor, for five of the bombs dropped had failed to explode. Only eight out of 2,700 machine tools and five out of 558 cranes had been destroyed.

Valuable crews and bombers were lost in 'Margin' (i) even though RAF Bomber Command had already that it must expect severe losses to unescorted bombers in missions of this type. Another lesson learned the hard way was that the Lancaster bomber’s rifle-calibre machine guns were wholly inadequate in daylight operations against German fighters fitted with armour, self-sealing fuel tanks and shell-firing cannon.

In the 235^th mission of the 'Big Week' campaign, the US 8^th AAF bombed the Messerschmitt aircraft factory in Augsburg by day on 25 February 1944, and in the night which followed RAF Bomber Command followed with an attack by 594 aircraft and completely destroyed the centre of Augsburg, in the process losing 21 aircraft, or 3.6% of the force, at least four of them in mid-air collisions.

These last bombings killed 730 people and injured 1,335, while 85,000 persons were left homeless, and nearly a quarter of all the city’s homes had been destroyed. There were 246 large- or medium-sized fires and 820 small fires. As the hydrants were frozen in a sub-zero night, fire-fighting was next to impossible.