Meanwhile the results of the air war over London showed that the A4 could be an economic weapon. Bombers were averaging only 5 to 6 missions, dropping only 6 to 8 tonnes of bombs before being shot down. Once the loss of trained flying crews was considered, the bomber cost 30 times more than the A4 to deliver a tonne of explosives on London compared to the expendable A4 at its production price of 38,000 Marks. But time was being lost in convincing others in the German leadership that the missile should be put into production. References: 693.