Designed in 1917, the Staaken E-4 was a stressed metal monocoque fuselage canatlevered monoplane 4 engined passenger aircraft with galley, w.c., baggage stowage and full communications. The most advanced aircraft of its time. Completed after the armisitice and extensively tested by the Allies who ordered it destroyed because of its potential as a bomber - it was faster than any Allied fighter of the day. The E-4's design philosophy can be seen again 20 years later in large civilian transport aircraft of the late 1930s and even the 1940s. For further information about this astonishing aircraft see Haddow & Grosz "German Giants", Putnam, 1988 and republished recently by Brassey, available on Amazon or Abe Books.