Electric aircraft

Question 1

Key concept of AEA

Answer 1

replace all hydraulic and pneumatic systems with electrically powered equivalents

Question 2

Power systems

Answer 2

schematic

Question 3

Technology to achieve AEA

Answer 3

electro-mechanical actuation electrically driven air condition compressors electric anti-icing electric engine starters

Question 4

Flight control actuation

Answer 4

FBW -(positional signals from cockpit to control surface) PBW - power-by-wire(electrical power to move control surface actuators)

Question 5

PBW benefits

Answer 5

improved maintainability reduced mass improved flight safety better reliability reduced aircraft operating costs

Question 6

Declared benefits of electro-hydrostatic actuators

Answer 6

high force lower hysteresis(<1%) - movement losses reduced pressure losses-no control valves efficient flow is controlled on demand pressure can be controlled electronically compact enhanced reliability- fewer system components and connections integrated diagnostic capability no centralised hydraulic system required

Question 7

Electro-mechanical actuators

Answer 7

uses electric motor to drive gearbox and screw jack drive if linear option is required can be susceptible to mechanical jam failure modes and aeroelastic oscillations due to play/stop in system mechanical drive suffers from friction and hence wear with the possibility of slack in the output

Question 8

B787

Answer 8

some electro-hydrostatic actuation electrically actuated wheel brakes electrical compressor based environmental control system electrical engine start electrical ice protection system