AHC staffer Larry Osborn is assisting a team of conservators at the Smithsonian National Air & Space Museum (NASM) which is currently conducting a condition evaluation of the sole surviving example of the Horten H IX jet powered all-wing aircraft that was in development in Germany late in World War II. Much of the aircraft structure is wood.
In 2011, conservator Peter McElhinney attended a wood anatomy & identification workshop for conservators through the American Institute for Conservation of Historic and Artistic Works (AIC), which was taught by Larry Osborn of the Appalachian Hardwood Center and Dr. Terry Conners of the University of Kentucky. He asked both to assist in wood identification on the Horten project late in 2013.
All basic assumptions about wood aircraft construction had to be questioned due to the unusual design and high performance requirements of this aircraft, combined with the rapidly deteriorating circumstances in Germany late in the war, characterized by increasingly limited availability of experienced pilots, raw materials, and skilled labor. The team is examining not just the aircraft structure but also all available reference material on the Horten designs, including declassified British and American military intelligence documents about the aircraft. This has also led to a review of economic intelligence documents about the state of the aircraft manufacturing industry and the wood products industry (especially plywood and adhesives) late in the war, in order to document materials, construction methods etc., so that any future preservation / restoration work done on the aircraft will be as historically correct as possible.
This is a long term project, and work is ongoing. Preliminary findings will be presented by NASM staff at the AIC annual meeting in San Francisco, May 2014.
For more information and photos see the Horten IX V3 "artifact" description at NASM. http://airandspace.si.edu/collections/artifact.cfm?id=A19600324000
There are other Horten all-wing designs currently on display at NASM, which are unusual in part for the prone or near-prone positioning of the pilot:
Horten H III f sailplane http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A19602081000
Horten H III h sailplane (center section only) https://airandspace.si.edu/collections/artifact.cfm?id=A19602082000
Horten H VI V2 sailplane https://airandspace.si.edu/collections/artifact.cfm?id=A19602083000
AHC staffer Larry Osborn is always available to discuss and assist with wood anatomy & identification, other wood technology topics, as well as aviation and history.