Vencelov is currently fabricating a part for the Aichi Seiran, a Japanese aircraft designed for the purpose of bombing the Panama Canal during World War II, a mission that was never carried out. The Museum has the last surviving example of the Seiran, which has just finished undergoing a 10-year restoration. Since the Seiran’s drift sight was missing, Vencelov was assigned to replicate the three-foot-long instrument.
Drift sights were used to measure the effects of wind on an aircraft in flight, enabling air crews to make course corrections en route. Drift sights were especially important to airplanes operating over water. Without them, a pilot could arrive over land without knowing exactly where he was, or which way he needed to fly to reach his target. In the case of the Seiran, the aircraft would have been launched from a submarine hundreds of miles from its target, and since the Panama Canal was heavily defended, staying on course was vital in order to preserve an element of surprise.
In the 12 years Vencelov has been at NASM, he has fabricated everything from the beaching gear tail strut on an OS2U Kingfisher to the Parabellum machine gun mount for a World War I German aircraft. “The trick is to visualize what it [the part] is going to look like when it’s done,” he says. For the Seiran drift sight, he started with a long piece of aluminum tubing, fashioning the central body of the sight by turning the tube on a lathe, much as a woodworker shapes the leg of a chair. He monitored the lathe closely to ensure that the bits didn’t overheat and that he did not remove too much metal; every couple of minutes, he stopped to check his progress. Says Vencelov: “Once you’ve removed the metal, you can’t put it back.”
After months of careful work, Vencelov is almost finished with the drift sight. The knobs function, the reflective sighting element looks perfect, and even a small handle acts just like the original—it doesn’t quite lock into place on its own. To prevent confusing future curators and researchers, the new sight will be labeled “Reproduced by NASM” and a note placed in the Seiran’s file.
When he’s finished, the drift sight will be installed in the rear cockpit of the Seiran, and Vencelov will move on to some other project. Most people will probably never notice his work, which is as it should be.