Smithsonian Collections Blog

Highlighting the hidden treasures from over 2 million collections

Collections Search Center

Tuesday, October 29, 2013

Restoration of the Curtiss SB2C-5 Helldiver: From Airplane to Archives Back to Airplane

True story: when you are restoring an airplane, you may need to make a trip to the archives. The National Air and Space Museum is working to restore our Curtiss SB2C-5 Helldiver, currently located in the Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center. This process involves many of the Collections units, including Preservation and Restoration, and Conservation. These units have had to work closely with the Archives Department. Why? We hold many of the documents—drawings, technical manuals, photographs—that guide the process! A good example of the relationship between the archives and aircraft restoration is the recent creation of a new clip for the Helldiver.

Curtiss SB2C-5 Helldiver in the Mary Baker Engen Restoration Hangar.  NASM 2013-03237

Earlier this year, NASM Restoration Specialist Will Lee removed the outboard trailing edge of the Helldiver’s elevator. Some of the component parts, including clips connecting the ribs to the trailing edge and the trailing edge itself, were damaged beyond repair. Given their current state, he determined that he would need to reconstruct this section of the aircraft completely. He decided to return to the original source—Curtiss manufacturer’s drawings for the U.S. Navy.

NASM Restoration Specialist Will Lee works on the Helldiver's elevator.  NASM 2013-03238
The National Air and Space Museum Archives holds over 16,000 rolls of 35mm microfilm covering over 600 different types of aviation equipment. This collection includes a set of eighteen reels of drawings for the Curtiss SB2C-3, SB2C-4, and SB2C-5. Each roll could contain up to 1000 individual drawings, though the average is about 400 to 500 drawings per roll. To complicate matters, the set was donated without an index!

The quality of the Navy microfilming process was mixed. Some drawings are completely legible; others are quite impossible to read. An intrepid group of seven museum volunteers worked six hours a day, four days a week, for four months to provide an index to the Helldiver microfilm. 

Using the index and a parts catalog from the Archives, Will determined which assembly drawing he needed for the individual clip. He then requested a paper reproduction from the Archives. Although many of the original drawings may initially be difficult to read, the Archives can work with the microfilm print to enhance its legibility.

The original assembly drawings, however, only give the actual size of the components, not the direct dimensions actually needed to manufacture the parts. Using the assembly drawing and several math formulas, Will calculated the proper dimensions to make his own construction drawing for the parts.

Clockwise from top: original assembly drawing, Will Lee's construction drawing, drawing attached to metal, and folded metal piece.  NASM 2013-03244
Will then photocopied his new drawing and attached it to a sheet of metal, folding the piece to fabricate the clip. After compressing a standard cylindrical tube to make an airfoil-shaped tube, he formed the rest of the elevator section. Then, using tubular rivets, he attached the newly fabricated clip to the newly fabricated tube to form part of the new elevator section.

New clip for the Curtiss Helldiver SB2C-5 (left) compared to the parts originally found on the aircraft.  NASM 2013-03240
This same scenario has played out for numerous members of the restoration staff as they request drawings for other parts and sections of the Helldiver. The Archives has been excited to assist with the restoration of the Helldiver and we look forward to its display at the Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Elizabeth C. Borja, Archivist
National Air and Space Museum Archives

1 comment:

  1. Wow! Great way to solve drawing problems as you slowly assemble the Helldiver!