Advent Aircraft Systems is developing an electric power brake system (ePBS) that offers the benefits of brake-by-wire technology to nearly any aircraft, including all-electric designs, new aircraft with traditional hydraulic systems, and older aircraft as a retrofit. The ePBS design incorporates Advent’s anti-skid technology, as developed in the eABS retrofit now available for the Eclipse 500/550; Beechcraft King Air series and T-6; and Pilatus PC-12. The ePBS is optimized for aircraft weighing 3,500 to 30,000 pounds mtow.
For manufacturers of new aircraft or retrofit applications, ePBS would eliminate hydraulic brake lines, master cylinders, and fluid from cockpits, while also adding an independent brake-by-wire emergency braking system. The hydraulic units are entirely self-contained in ePBS.
An ePBS system weighs approximately 30 pounds and, according to Advent, “consists of brake pedal sensors and feel units, a primary brake electronic controller, parking and emergency brake controller, wheel speed transducers and hubcaps, and both primary brake and emergency/parking brake hydraulic units. The electronic controllers would send commands to the brake valves, using state-based logic, based upon the applied brake pedal force. There are no quirky system behaviors for which the pilot must allow.” An advantage of ePBS compared to existing power-brake systems is that it doesn’t require a hydraulic accumulator or nitrogen bottle to power the emergency brake.
“The emergency brakes would be independent and isolated so that no primary brake system components or sensors would be needed for the emergency brakes to operate,” according to the company. “A separate hand control would be used to operate the emergency brakes. The health and readiness of the emergency brake would be verified every time the pilot sets the parking brake. Additionally, the emergency brake could be operated, for practice, on any landing without requiring any maintenance actions at all.”
Advent is offering ePBS to aircraft manufacturers to incorporate in existing designs or for new aircraft programs. While ePBS could be certified as a retrofit, that would require more work to remove the existing brake system and all of its components. Its ePBS would also be "ideally suited" for unmanned aircraft systems. “We see this as a product where we would collaborate with an OEM [for a new program] or upgrade ePBS to an existing airplane to incorporate into future production,” said Advent managing director Ken Goldsmith.
“The advantages of brake-by-wire have been to get all hydraulics out of the pressure cabin, which has been a regulatory issue from a fire-safety standpoint for a long time,” said Advent Aircraft president Ron Roberts. “All-electric airplanes [and others] are getting rid of centralized hydraulic power systems. This is still hydraulic, but it’s an isolated and dedicated system. We can give them an elegant system, where the brake control and feel is very refined. The ePBS would provide a natural feel, allowing the pilot to modulate the braking action for smooth directional control.”
Advent is discussing ePBS with aircraft manufacturers and is prepared to help an OEM incorporate ePBS in an upcoming program, according to Goldsmith. “We would relish discussions with any OEMs that might have interest,” he told AIN. “We’ll answer any questions and offer a solution that they weren’t aware was available.”