Carl Goldberg’s Prototype Zipper

Free Flight was forever changed after the introduction of Carl Goldberg’s Zipper model at the 1938 Nats.  The model, with its raised pylon, undercambered airfoil and polyhedral wing is unmistakable and iconic.

Carl Goldberg's Prototype Zipper is covered in a buff tissue  We are unsure what the original color was.
Carl Goldberg’s Prototype Zipper Model Airplane, National Model Aviation Museum Permanent Collection, donated by Beth Goldberg, 2000.49.01.

Want to know why the Zipper is so famous?  Watch this Fly-By!

The Zipper in the museum’s collection is one of the original 1938 prototypes with a diamond-shape fuselage.  It was donated to the museum by Carl’s wife, Beth Goldberg.  We’re working on making it available in a 360 rotational view – this will be available soon!

Fun Fact:
In the Spring of 1938, the Chicago Gas Model Aeronauts held a contest for model airplanes with a wingspan of 4 foot or less.  The thought was that this meant the models would be forced to use smaller engines.  However, they did not specify the size of engine required.

Carl disagreed and pushed to have the engine size limited.  No one else thought it was necessary.  This lead to a bet between Bob Forster and Carl.  Carl would be able to keep one of Bob’s Forster .99 engines if he could fly it with model limited to a four foot wingspan.  If he couldn’t, well, no engine.  Carl quickly built a 4 ½ foot wing, modified one of his Clipper fuselages and put the two together.  He then proceeded to win the contest – and keep the engine.

The paper of the ID label is turning brown and the handwriting faded, but it clearly states taht this model belongs to Carl Goldberg at a Chicago address.
Carl Goldberg’s original ID label on the Prototype Zipper. Hidden on top of the pylon under the wing it is only visible when the model is not assembled.
Longerons are angled in an alternating right and left pattern to support the Prototype  Zipper's diamond fuselage.
An interior view of the prototype’s Zipper’s diamond-shaped fuselage.

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