The Firefly™ is an all-electric technology demonstration aircraft from Sikorsky Innovations. With Firefly™, Sikorsky plans to demonstrate and quantify the benefits of an electrically powered helicopter. On a broader scope, the project aims to drive future development of state-of-the-art, environmentally-sound technologies and practices in the industry. Firefly™ is a stepping stone in a vision to provide zero emission vertical flight that is smooth, quiet, clean, simple, reliable and affordable.
Beginning with the safe and reliable S-300C™ platform, the team replaced the legacy propulsion system with a high efficiency (>95%) electric motor and digital controller from USHybrid coupled with a state-of-the-art, lithium ion energy storage system. Integrated sensors provide real-time aircraft health information to the pilot through a panel-integrated, interactive LCD monitor. Eagle Technologies, LLC, executed the custom airframe modifications and assembly of the demonstrator aircraft.
Firefly™ is comprised of a number of first-in-class innovative features, including:
· 190 hp, high efficiency and power density electric motor
Weighing only 180 lbs with controller, the electric motor was designed to mimic power profiles of the legacy motor to minimize integration time and complexity.
· Safe and efficient high density energy storage system
Two battery packs, each containing a series of 45 Amp-hr lithium-ion cells comprise the energy storage system. For the Firefly™ application, Gaia provided a new chemistry battery cell, combining the best of their High Power and High Energy battery chemistries to meet the required energy demands.
· Automated monitoring and alert technologies
Sensors embedded within the mechanical, electrical and energy storage components provide real-time health data. Relevant results of this system are presented to the pilot real time in a standard symbology format.
· Advanced flight control system
Driven by the embedded sensor network, the mode-based flight control system features automated operation sequences and safeguard functionalities which monitor current aircraft conditions to ensure safe operating limitations are maintained throughout the flight.
All-electric propulsion offers substantial benefits for current and future rotorcraft designs. With Firefly™, the development team has demonstrated a propulsion efficiency increase of roughly 300% from baseline. In addition, electric motor technology is progressing in a direction that may, in the near future, negate the need for traditional rotorcraft drive components. This simplification not only reduces the number of moving parts, but directly results in significant noise reduction, reduced vibrations, and game changing advances in reliability with associated dramatic decreases in direct operating costs.
In its current configuration, the demonstrator has an expected flight time of 5-10 minutes, but as energy storage technologies improve, flight time will increase. While the maturation of a practical electric helicopter is dependent on the growth of battery energy and power density, Sikorsky Innovations intends to push the boundaries of helicopter and energy storage technology to achieve the Firefly™ vision.