After this raid, both "Kagohl" 3 and Rfa 501 were principally used for army support. The development of the B-1E "Elektron" incendiary bomb, led to a project, "Der Feuerplan" (The Fire Plan), which involved the use of the whole German heavy bomber fleet, flying in waves over London and Paris and dropping all the incendiaries that they could carry, until they were either all shot down or the crews were too exhausted to fly. The hope was that the two capitals would be destroyed in an inextinguishable blaze, causing the Allies to sue for peace. Thousands of "Elektron" bombs were delivered to forward bomber bases and the operation was scheduled for August and again in early September 1918 but on both occasions, the order to take off was countermanded at the last moment, perhaps because of the fear of Allied reprisals.