The Whisper Prop
Anyone who ever flew the Electra would agree that it was one of the finest airplanes to fly that was ever designed. I flew the model with the squaretip Aero-Products Propeller, but I suspect the round tip Ham Standard had all the same bells and whistles, 11 safety features on just the prop! It was a faster airplane across the ground (VMO 410) than the 707 or 727 (VMO 390) until the two "whirl mode" crashes. After those two (Braniff and Northwest), one of the fixes was to re-angle the engine mounts and slow the plane down. It was still immensly fun to fly. Flight Training routinely shut 3 engines down and cruised along on one, inboard or outboard (for demonstration purposes).