05 - System: Hydraulics

Question 1

Hydraulics: The Ecureuil hydraulic system is of what type?

Answer 1

• Constant power

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.1.1)

Question 2

Hydraulics: How is power to the servo controls defined?

Answer 2

• POWER = P (pressure) x Q (Flow rate)

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.1.1)

Question 3

Hydraulics: How does the Ecureuil hydraulic system maintain constant power?

Answer 3

• Constant flow rate from the pump (6L/min, which is excessive for normal flight)
• Regulating valve (Maintains 40 bar)

Further explanation: The regulating valve maintains the pressure at 40 bar, by returning the excess hydrulic fluid to the tank. If the demand increases, all the regulating valve has to do to maintain power to the servocontrols is to reduce how much fluid is returned to the tank.

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.1.1)

Question 4

Hydraulics: What indications does the pilot get when the hydraulic pressure drops?

Answer 4

• HYD warning light
• Horn

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.3 - 2)

Question 5

Hydraulics: Each servocontrol has a non return valve. What does this ensure?

Answer 5

Prevents return flow so the accumulator pressure is discharged to the servo, in case of loss of system pressure.

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.3 - 2)

Question 6

Hydraulics: Which solenoids open when you switch the hydraulic pressure switch to off?

Answer 6

• Main servos solenoid valves

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.3 - 5)

Question 7

Hydraulics: Which solenoids open when you press the HYD TEST switch?

Answer 7

• The HYD TEST solenoid which allows supply line flow to return to the reservoid.
• The accumulator solenoid valve for tail load compensator

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.3 - 5)

Question 8

Hydraulics: What drives the Hydraulic pump?

Answer 8

Belt drive from the shaft input to the main gearbox

(Instruction Manual - Basic 1 - Main Systems, Chapter 8, Paragraph 8.2.5)