Dreamliner battery nightmares have troubled the dreams of electric flight for the past two years. Michael Ricci, Vice President of Engineering with LaunchPoint Technologies, gave attendees at this year’s Electric Aircraft Symposium a crash course (pun intended) in the many types of failure modes electric aircraft face. Luckily, he also provided ways to mitigate and eliminate those failure modes. He introduced a concept called “Propulsion by Wire” (PBW), the main thrust for electric aircraft and roughly akin to the commonly discussed “Fly by Wire” concept. Asking what product specifications for electric propulsion will look like, he answered his own rhetorical question with the technical requirements for reasonable interaction, a useful user interface, airworthiness, and safety. Starting with the last issue first, safety (which should always come first), we need to be able to continue safe flight after a single component failure. There are some surprising, counter-intuitive things at work here. Depending on whether we start with a qualitative hazard analysis …