While we wait (with increasing patience or impatience depending on our personalities) for the next round of battery developments to make pure electric airplanes a reality, hybrid possibilities abound. The definition of “hybrid” might not be as coherent as those used for automobiles. Some “hybrids in this entry allow extended letdowns following a primary engine failure. In that case, the added electric motor/generator gives extra minutes to find a safe landing space. While both motor and primary engine are operational, the system acts much like an automotive hybrid system, both motor and engine combining outputs for added power, or the electrical portion recharging batteries while the engine maintains cruise power. Some are more like automotive serial systems, an engine-driven generator charging batteries which power the propulsion motor. Pipistrel, though the Hypstair project, has a 200-kilowatt (268-horsepower) unit ready for test flights in 2017, according to Tine Tomazic, Director of Research and Development. Several Flying Now Several years ago, Flight Design …
EAS IX: Mike Ricci Explains PWB, Safety
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 …
Making the Siemens Motor Light and Powerful
Siemen’s recently-announced 260 kilowatt (348.5 horsepower) motor has brought several comments, one from a skeptical blog reader who asked some interesting questions. “VO” or “Volker” comments on Siemen’s claims for the motor, and throws in speculation as to the company’s veracity. (Note to readers who submit comments: please don’t attribute conclusions not intended by the editor, as in the last sentence of VO’s comment, and avoid speculating on the honorable intentions of those who announce new concepts or projects.) “The first three you mention are kind of concepts but with reasonable or high efficiency. What is the efficiency of the Siemens motor? And whose tech are they using? They have been circling the makers you mentioned for years. Did they license something or steal again? On most you mention, I could find efficiency numbers (Emrax with a whopping 98%?) and more or less detailed specs. I don’t know. Looks like a marketing ploy. “Typically, you would see boasting with efficiency …