For over twenty years I had the good fortune to serve Sikorsky Aircraft as a consultant in acoustics and noise control , During this period I had Mr. Sikorsky pointed out to me as he went about the engineering department. I often thought that this was the man who had been the creator of what was a major contribution to the aircraft industry.

Igor SikorskyOne day, in or about 1963, the people that I usually ate lunch with were unable to get away from their work. I was sitting alone in the executive dining room when Mr. Sikorsky stooped at my table and graciously asked if he could join me. I, of course, said yes and that I would be pleased to have lunch with him. He asked me my name and what I was doing at Sikorsky. When I replied that I was consulting on helicopter noise research he immediately became interested. The conversation ranged over a number of subjects concerning the cause and possible treatment of external helicopter noise. He asked if I knew why owls and other large raptors fly silently. I said that my guess was that the wing tip feathers broke up the wing tip vortices.

This sparked his interest and we spent the rest of the hour sketching rotor tip designs on napkins and backs of menus. That afternoon I received a telephone call from another consultant who was an aerodynamicist. He said that Mr. Sikorsky had asked him to call me. We discussed rotor tip modifications for the rest of the afternoon. While we did not come up with a possible change in tip design that afternoon, later research focused on the tip vortex as an important contributor to helicopter noise with positive results.

The image of an alert, inquisitive engineer and inventor remains with me to this day.  Also, his gracious manner left a warm feeling toward this great man

Harold R Mull


last update SEPTEMBER 22, 2012