The Hawker Heron was the first fighter aircraft designed at Hawker Aircraft with a basically metal structure. Sydney Camm was the chief designer that introduced what became the typical structure for all Hawker aircraft until the introduction of the jet-powered Hawker P.1040. This structure consisted of metal tubes (steel or aluminium) with their ends swaged so that they could be connected to each other by means of "fishplates" and bolts (sometimes with ferrules to protect the tubes).
The Hansa-Brandenburg D.I, also known as the KD (Kampf Doppeldecker) was a German fighter aircraft of World War I. Despite poor handling characteristics it was put into service by Austria-Hungary, where some aircraft served until the end of the war.
