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Preserving and Displaying the “Bat-Wing Ship” – July Update

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This post is a follow up to Preserving and Displaying the “Bat-Wing Ship” published on September 9, 2011.

After preparing hundreds of condition reports last winter on the many artifacts that curators plan to exhibit in the upcoming Time and Navigation gallery opening at the Museum in Washington, DC in April, 2013, while simultaneously helping the Collections Processing Unit move artifacts from the Paul E. Garber Facility to new digs at the Udvar-Hazy Center in Chantilly, Virginia, Museum staff could finally return to work on the center section of the Horten H IX V3 jet fighter, the “Bat-Wing Ship.”  With help from retired treatment specialist Karl Heinzel, Museum conservator Lauren Horelick is determining the best methods to stabilize and protect the center section for movement to the Mary Baker Engen Restoration Hangar at the Udvar-Hazy Center later this year. Lauren carefully mapped the object to establish a baseline of problematic areas and to complete an essential step in recording present damage [Figure 1].

condition map

Figure 1: In-progress condition map showing the types and extent of damage currently seen on the metal components of the center section (Lauren Horelick photo, modified Arthur Bentley drawing published in Shepelev and Ottens, Horten Ho 229, Spirit of Thuringia, 2006).


In addition to creating written and photographic documentation of the jet, Lauren is conducting material identification analysis to identify the wood used to make the plywood, the adhesive used to bind the micron-thin layers of the plywood, and the adhesive used to join the large structural members of the wood panels. Her analysis will not only add to the history of the Horten wing, it will also help her craft the best conservation treatment protocol.  Summer interns working with scientists at the Museum Conservation Institute are contributing to the materials identification effort.  We will blog the results at the end of this summer.

We have begun initial effortsto protect the center section during the move to the Restoration Hanger.  These efforts include removing the fragile plywood belly panels so that conservators can treat the wood for long-term stabilization before reattaching it.  To remove the wood panels safely, it was necessary to apply a facing over sections of the wood to prevent loss of material [Figure 2].


Figure 2: Lauren carefully attached a sheet of Reemay, a non-woven spun bonded polyester, to cover a section of fragile and delaminating plywood on the underside of the center section. She used BEVA (Berger’s ethylene vinyl acetate) film, a reversible heat-set adhesive, around the perimeter of the Reemay sheet to hold it in place and stabilize the wood so that the panel can safely be removed for later treatment. Lauren cut the small holes seen in the Reemay to provide access to the bolts securing the panel to the steel tube support frame.

Other conservation efforts include researching adhesives to stabilize the plywood and developing methods to address how to move the center section to the Udvar-Hazy Center.  Lauren is considering a multi-layered envelope system that would enclose the entire center section during travel.

Russ Lee is a curator in the Aeronautics Division of the National Air and Space Museum and Lauren Horelick is a conservator in the Collections Division of the National Air and Space Museum.



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15 thoughts on “Preserving and Displaying the “Bat-Wing Ship” – July Update

  1. At least. Walter and Reimar will be glad up there looking down how their wonderful plane receives at least the treatment that deserves.

  2. Any thoughts about the National Geographic Channel building a full size replica, testing its radar signature, and its combat potential if properly used and in sufficient numbers?

  3. Lauren has clearly completed superb documentation and is undertaking a thoughtfully conceived treatment approach! Looking forward to hearing more!

  4. Lauren’s work is outstanding and we are lucky that she is so enthusiastic about this project. We should praise National Geographic for their hard work to build and study a copy of the H IX. An all-wing design will usually reflect less radar energy than a conventional design because it has fewer oblique surfaces and corners to reflect the beam. I believe that Reimar shaped the H IX solely for aerodynamic reasons. He used wood for the outer wings and plywood, sheet metal, and steel tube to construct the center section because those were the materials he used to build all of his other aircraft, therefore he was most familiar with them. Wooden components happen to absorb more radar energy than metal.

  5. I am so glad to see this plane get restored.
    I am building a 1/8th Radio controlled model of the HO229 and can’t wait to be able to come and look close up at the most secret plane of WW2. I just wish that this plane was back in the UK and not in the USA so I could be closer to it.

    Great work and keep us informed.

  6. Would Like To Make Contact With Russell Lee (Again) – Last Time I Spoke With Russell He Had Just Retired – 1st Met Russ When He Was Attending The Univ. Of Texas & He Worked As A “Grunt” On Old W.W.2 Airplanes Here In San Marcos Tx Back In The Late ’70’s – My E-mail Address As Entered Above Would Be The Best Mode Of Contact For Now – “If” One Of Your Kind Associates Would Make Sure Russell Gets “This” Request – Thanx! – Ray S. Harper – San Marcos, Tx / / Advise / /

  7. Thanks for your inquiry, Mr. Harper. We will make sure Russ gets your email address.

  8. I have been waiting for this restoration for years – thank you! What a project. What a priviledge. From its presence in the media of late, there seems to be widespread and enduring interest in this plane.
    Now – has there been any word lately on plans for the Kyushu J7W1 Shinden?

  9. Pingback: Preserving and Displaying the “Bat-Wing Ship” – March Update | AirSpace

  10. I had the privilege of helping with “Hitler’s Stealth Fighter”, the NatGeo documentary. I have since been corresponding with David Myhra, Arthur Bentley and Mike Jorgensen, all of whom I had the pleasure to get to know during the making of HSF. There is some evidence that a carbon based material was used in the finishing process on the Ho IX, particularly in the leading edges of the wings and center section.

    @NASM staff: has anyone done any materials study to confirm this?

    If this is true, it would at least lend some credence to the claim that the Horten brothers gave some thought to RCS, even as it was poorly understood at the time.

    This is one of the things that makes this aircraft so interesting. There are many mysteries surrounding it. The Horten brothers themselves have contributed to the confusion by making claims post-war that were dubious and probably motivated by self-promotion.

    Another mystery: what were the small air scoops on the bottom of the center section for? I tried to trace these when I was there based on what I could see with a flashlight, but was never able to confirm their function. Some have speculated they were for boundary layer air in the exhaust area. With our flying scale models, we have confirmed turbulence problems in the exhaust area since there is such a large area on the upper surface exposed to the exhaust flow. Our models will not in fact fly properly without some separation of the exhaust flow from the airframe. We have used extension tubes for that.

    It’s great to see the center section being cleaned up. Kudos to Lauren for her work with this fascinating aircraft.

    David Myhra is beginning work on a final volume on the Ho IX. He is now making available his recent work as eBooks on Amazon. He and Arthur are getting on in years, they have both been a great resource for documenting what is known about the Ho IX. David mentioned that some are resurrecting the “Go” (Gotha) designation, since Gothaer Waggonfabrik indeed was undertaking license production of the Ho IX at war’s end. However, since they never completed or flew an example, the debate will go on :-) Personally I prefer to use the Horten (Ho) designation as it credits the people who designed the aircraft.


  11. Gary, thank you for your comments and your interest in the Horten project and NASM. Lauren and her team are planning to conduct their own study of the H IX V3 to determine if Reimar Horten used some type of carbon material on the leading edges of the jet wing. Lauren’s problem is detecting the carbon for not only does carbon absorb radio waves, it also absorbs the energy sources, including infrared light waves, and the laser light used with the Raman Spectrometer, that conservators routinely use to analyze materials. One technique that does work, Polarized Light Microscopy, makes carbon look like ordinary dirt! Therefore, Lauren’s team will also attempt to devise a simple and reliable method for detecting carbon. She would be very interested to know what tools and techniques the team from Northrop used when they spent the day studying the Horten jet wing at the NASM Paul Garber Facility several years ago.

    I have been unable to locate the small air scoops on the lower center section about which you inquired. Besides the landing gear bays and the airbrake located at the aft end, I can only discern several small openings where maintenance panels were removed.

  12. Thanks for the info Russell. The small air scoops I’m referring to are visible in the 3-views. It looks like they were not yet installed on the v3, but the holes are visible. They are about 2′ aft of the engine intake fairing on the underside of the center section. And here’s another mystery – why did the v3 have such a nose-high attitude on the ground? Experiments with models have shown that this attitude results in premature rotation and bouncing on takeoff. With our models we normally size the LG struts to give just a few degrees of positive AOA for takeoff. A negative AOA is advantageous for landing, so some have installed variable length nosegear for this reason. This makes the aircraft “stick” to the ground on landing. Bouncing landings are very common otherwise if you don’t bleed off enough airspeed. Needless to say this is a challenging model to fly, as was I’m sure the full size aircraft!

  13. Russell, I hope to see the Horten IX v3 completed before I pass on. Did you fellows ever display the Nagajima kamikaze altimeter I donated saved from the carrier Enterprise during the battle of Leyte Gulf? Remember you also have the Kyushu Shinden to restore the first true canard aircraft. Regards to you and your family. Allan

  14. Hi Allan, yes we have the altimeter but it is not yet on display. Thank you again for the donation and best regards to you and your family.

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