The private pilot departed on a cross-country flight in his recently purchased high-performance experimental amateur-built airplane. About 25 minutes after takeoff, the pilot informed an air traffic controller that he was experiencing electrical problems and requested to divert to the airport where his maintenance facility was located. The pilot further stated that his electrical system was not charging and that he expected he may lose radio communications due to the loss of electrical power. The pilot continued about 30 minutes to the diversion airport. Radar data revealed that, about 1 minute after being cleared for landing, the airplane's transponder stopped sending altitude information, consistent with electrical power decreasing below the 18 volts required to power the radio system. The pilot performed a low pass over the runway, presumably for the tower controller to confirm that the landing gear were extended; although the pilot was not in communication with the controller, the controller transmitted that the gear appeared to be down. The airplane continued on a close-in downwind leg and turned onto the base leg of the traffic pattern; witnesses saw it enter a steep left turn followed by a near-vertical descent consistent with an aerodynamic stall. Examination of the wreckage revealed no evidence of preimpact mechanical malfunction or failure that would have precluded normal operation; however, the electrical system was consumed by fire, precluding functional testing or examination of its components. The starter-generator drive shaft was fractured in overload, consistent with it turning at the time of impact. The pilot had owned the airplane about 3 months, during which time he logged about 40 hours of flight experience in it, including transition training with a provider who specialized in the accident airplane make and model; however, the pilot's most recent experience was flying about 35 hours in his other airplane, which operated at much lower airspeeds. The transition between the airplanes may have contributed to the pilot's failure to identify that he had let the airspeed drop below stall speed during the landing approach. The accident airplane had experienced electrical problems several days before the accident; however, the pilot's handling of that situation suggested a lack of familiarity with the airplane and its emergency Page 2 of 16 WPR17FA155procedures. During that event, he allowed the airplane to become slow at low altitude while troubleshooting, and he attempted to activate the emergency landing gear extension system, but instead pulled the parking brake handle. Despite the fact that the airplane's published generator failure checklist included recycling the generator switch, the pilot was only able to remedy the electrical problem after an individual at the maintenance facility instructed him via cell phone to recycle the generator switch, which he did. After restoring electrical power and landing without incident, the pilot admitted that he had forgotten to turn the generator switch on in the first place, an item that was included in the airplane's after-start procedures. During the accident flight, the pilot displayed similar evidence of failure to follow the airplane's published emergency procedures, which, for a generator failure, included reducing the electrical load by turning off nonessential equipment and landing at the nearest suitable airport. Onboard photos of the instrument panel during the flight indicated that the air conditioner, a nonessential item, remained on after the pilot initially reported electrical problems to the air traffic controller. Additionally, the pilot chose to continue the flight for 30 minutes to his maintenance facility, overflying other airports at which he could have landed. (The emergency procedures noted that battery power would last about 30 minutes with all nonessential equipment off.)  Finally, the pilot was likely distracted from his primary task of flying the airplane as he was text messaging the maintenance facility about 8 minutes before the accident and placing a phone call within the 3 minutes before the accident, which may have been an attempt to reach the tower controller to confirm the status of the landing gear. Due to the postcrash fire, the origin of the electrical system failure could not be determined. Based on the available evidence, the accident is consistent with the pilot's failure to maintain airspeed while maneuvering for landing, which resulted in an exceedance of the airplane's critical angle of attack and an aerodynamic stall/spin.