PILOT'S GUIDE DIGITAL REDUNDANCY & PLUG-AND-PLAY CAPABILITIES Avionics that meet a homebuilder's operational and economic needs S T O R Y B Y S C O T T I t's been more than 30 years since the McDonnell Douglas MD-80 and Boeing 757/767 introduced glass cockpits to aviation. The succeeding generations of these systems give pilots an ever-growing ratio of capabilities to cost. Digital avionics and their displays are standard equipment on most aircraft manufactured today, and many of the airplanes that preceded them are Photo by S.M. Spangler The Sonex Aircraft JSX-2 SubSonex single-seat jet - 40 - M . S P A N G L E R updating their analog systems with glass. Pilots who are amateur builders of experimental aircraft have the same needs and desires as those who fly store-bought airplanes. But because they assume some of the risk addressed by the certification requirements production aircraft must meet, homebuilders have more freedom in designing avionics systems that meet their operational and economic requirements while ensuring the desired level of reliability and safety. Redundancy is one of the hallmarks of aviation safety. If the primary system fails for whatever reason, the backup will sustain safety through the precautionary landing. When it comes to the instruments essential to flight, tried-and-true analog and steam gauges are the go-to backups. But two builders, an individual and a company that designs experimental aircraft kits, have taken the next step by relying on digital redundancy. David Halmos - Van's Aircraft RV-10 " Avionics technology is at a level where we have enough redundancy and ways to build the system so that we don't have to have steam-gauge backups," said David Halmos, a prosthodontist (a specialist in prosthetic dentistry)