Specifications include, but are not limited to: A. The aircraft shall be rotary-winged capable of vertical take-off and landings. B. The entire system (aircraft, remote controller,) shall be capable of operation using only rechargeable battery power. C. The battery charger shall be an AC and DC source charger capable of charging any two system batteries simultaneously. 1. The AC Charging Power requirements are 110v 2. The DC Charger Power requirements are as follows: a. The DC charger shall operate from a 12‐24 V DC power source b. The battery charger (s) will automatically recognize system batteries, and evaluate cells, and charge batteries with no operator interface other than connecting batteries. A simple status indicator shall be provided. D. During operator system preflight the system shall perform a BIT for 95% identification of faults and isolate failed components < 3min to complete.