Sidewinder Sidelights

I was particularly interested in your article on the Sidewinder missile (“Sidewinder,” by Ron Westrum and Howard A. Wilcox, Fall 1989) as I had the recent pleasure of contributing to its continued success.

While serving with the Missiles Division of LTV Aerospace & Defense, I was part of a small team working on a Navy-funded project concerned with the redesign of the aft fins, or “wings,” which have changed little since the early design. The supersonic speeds involved in captive carry and firing generate sufficient heat from air friction to affect the strength of the thin aluminum wing skins. To protect the skins a thermal coating is applied during manufacture. This adds not only cost but also drag, because of its coarse “orange peel” surface texture. Also, it has been known to flake off during storage and handling.

The new concept involves a onepiece, wraparound skin of advanced material: RST (for rapid solidification technology) aluminum. This, together with a modern high-performance adhesive, eliminates the need for a thermalprotection coating and the past process of riveting two separate skins onto the wing frame. Navy testing thus far has shown success in the design, and it testifies to the benefit of close teamwork between design engineering and manufacturing engineering.