EAS IX: Short Circuiting Batteries on Purpose

Dean Sigler Electric Aircraft Components, Electric Powerplants, Sustainable Aviation Leave a Comment

Recent news from the world of insurance claims adjustors brings us back to ways inspired battery designers might reduce or eliminate certain types of claims, and make electric flight safer. Even when international agreements don’t make progress along those lines. Insurance Claims and international Agreements With recent news of Federal Aviation Administration interest in lithium-ion batteries arising from fires caused by thermal runaways, shipments of large numbers of batteries may be banned.  Claims Journal, an insurance industry news line, quotes Angela Stubblefied, an FAA hazardous materials safety official, as saying, “’We believe the risk is immediate and urgent.’ She cited research showing the batteries can cause explosions and fires capable of destroying a plane. “FAA tests show that even a small number of overheating batteries emit gases that can cause explosions and fires that can’t be prevented by current fire suppression systems. Airlines flying to and from the U.S. that accept lithium battery shipments carry 26 million passengers a year, …

EAS IX: Neil Johnson of Navitas on Battery Safety

Dean Sigler Electric Aircraft Components, Electric Powerplants, Sustainable Aviation Leave a Comment

Neil Johnson of the Navitas Systems Advanced Solutions Group gave the gathering at the ninth annual Electric Aircraft Symposium an overview on battery reserve limits and gauging, and the methods necessary to address the different failure modes for lithium batteries, all of which could be problematic for electric aircraft. Navitas includes some legacy technology adapted from 123 Systems, typically 18650 format batteries, an 18-millimeter by 65-millimeter cylinder with active materials separated by a dialectric separator material in a “Tootsie Roll” configuration.  Some of the chemistries involved were developed for Formula 1 racers, and according to a talk given by Bill Dube’ and Eva Håkansson, are considerably more powerful than “conventional” lithium cells. According to Neil, the five billion cells out there now have been vetted using failure mode and effects analysis (FMEA) and fault tree analysis (FTA), two methods of statistically analyzing failure modes and of determining what might become failure modes in new designs. FTA. As Neil shared with the audience, …

EAS IX: Chip Erwin Follows Up and Follows the Rules

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Chip Erwin is one of many who are trying to find less expensive ways for people to experience personal aviation.  His company, Aeromarine LSA, fields a range of small aircraft, but he has taken a turn toward the lighter end of the market with his latest offerings. We wrote last month about his dinner presentation at the ninth annual Electric Aircraft Symposium and this month he’s followed up on several of the craft he discussed that night. His web site explains the different rules and regulations that govern small aircraft.  Many rules are not yet established (electric motors in U. S. light sport aircraft, for instance).  The second segment of the “About Us” section of Aeromarine’s web site describes each of four different sets of regulations – a collection that must stress aircraft designers working on small, light aircraft. Four major rules guide how ultralight aircraft may be flown.  FAR Part 103, the guiding light for ultralight designers and pilots …

EAS IX: Low Aspect Ratio Airplanes – Against the Grain

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Barnaby Wainfan is a technical fellow with Northrop-Grumman, but possibly best known for the FMX-4, well known as the “Facetmobile.”   His talk on “Low Aspect Ratio Electric Airplanes gave attendees at the ninth annual Electric Aircraft Symposium a great deal of counter-intuitive insights into how a successful airplane can look and work. The FMX-4, he pointed out, is a low-aspect-ratio, light weight, single primary structure, low-parts-count airplane with benign flying qualities.  When, as he told his audience, he decided to stop talking and start testing, he began with X-Plane computer simulations to check out his theories and studied simple, fast-building structures that would get him into the air expeditiously. N117W was easier to build than curved sticks, and despite its angular lines, the airflow doesn’t separate over its flat surfaces.  He could carry an approach at 10 degrees positive angle of attack (AOA) and still have 30 degrees available before reaching a stalling point. The airplane carries a payload equal …

EAS IX: Airbus Looks to a Light Electric Future

Dean Sigler Electric Powerplants, Sustainable Aviation 2 Comments

Ken McKenzie, listed as Deputy Chairman of Airbus US, has served as Vice President for Airbus Customer Services and as Chief Operating Officer for Airbus Americas, Inc.  This high-powered individual comes across as a relaxed, congenial soul, though, and led attendees at the ninth annual Electric Aircraft Symposium through an overview of developments in light electric aircraft to come from the aviation giant. The e-Fan is the most visible effort for Airbus’s electric aircraft work so far, but the company is intent on carrying out a full E-aircraft program as part of its commitment to the European Commission’s Flightpath 2050 program,. which bullet-points these important goals for the next 35 years: “1. In 2050 technologies and procedures available allow a 75% reduction in CO2 emissions per passenger kilometer to support the ATAG (Air Transport Action Group) target10 and a 90% reduction in NOx emissions. The perceived noise emission of flying aircraft is reduced by 65%. These are relative to the …

Making the Siemens Motor Light and Powerful

Dean Sigler Electric Powerplants, Sustainable Aviation 2 Comments

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 …

Siemens Makes a Big, Light Motor

Dean Sigler Electric Powerplants, Sustainable Aviation 2 Comments

Its 14 kilogram (30.8 pound), 85 kilowatt (114 horsepower) motor already graces the nose of the PIpistrel WattsUp, and Siemens seems to have expanded its aeronautical offerings with its new 50 kilogram (110 pound), 260 kilowatt (348.5 hp.) unit.  According to Dr. Frank Anton, Head of eAircraft at Siemens Corporate Technology, the new motor “make[s] it possible to build series hybrid-electric aircraft with four or more seats.” Siemens claims a world record of five kilowatts per kilogram, although Roman Susnik, with his Emrax motors pulling close to 10 kilowatts per kilogram, might contest that, and LaunchPoint is working toward eclipsing that mark.  To be fair, it’s certainly a giant boost over the power-to-weight ratio of most industrial-type electric motors, which Siemens also produces in large numbers. The company, according to its press release, intends to start flight testing the new motor before the end of this year, and hopes to increase output even more. In 2013, Siemens partnered with Airbus …

Spinning Electrons with Silicon Paper Electrodes

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Husband and wife team, Cenzig S. Ozkam and Mihri Ozkam and their graduate student, Zach Favors, have achieved another innovative approach to creating better batteries.  The blog has cited the Ozkan’s earlier effort that involving a new architecture for high-performance batteries capable of charging and discharging at much higher rates, and Favors’ discovery that beach sand in nano-sized form has some potential to increase battery performance considerably.  It’s silicon, after all. Zach Favors will share his findings in his presentation, “Beach Sand for Long Cycle Life Li-Ion Batteries,” at the ninth annual Electric Aircraft Symposium. The three, working in the University of California, Riverside’s Bourns College of Engineering “have developed a novel paper-like material for lithium-ion batteries,” with “the potential to boost by several times the specific energy, or amount of energy that can be delivered per unit weight of the battery.” etched SiNF paper, and (d) C-coated SiNF paper as used in the Li-ion half-cell configuration. The material can be spun …