Dual Hydraulic Flashcards
What Supplement contains info for the Dual Hydraulic system?
Sup 23
What supplement contains the increased internal Max Gross Weight, performance data and planning?
Sup 28
What other additions are included in the Dual Hydraulic instalation?
Reinforcement of the cabin floor
Tail boom junction
Mods to the MGB
MR mast and TR gearbox
New upper cowlings
Mod to the engine firewall
Control mods
Components of the system
2 Independent Hyd Systems each with -
Pump set to 35bar pressure
Distributor
Reservoir
Describe the distributor
Identical for each system
3 micron filter
Clog indicator
Low pressure switch
Pressure regulator valve
At what pressure is each system set to?
35bar +/- 1bar
At what pressure does the low pressure switch close?
< 20bar
At what pressure does the clog indicator pop?
2.7bar differential pressure
How are each of the pumps driven?
Gear driven pump on system 1
Belt driven pump on system 2
List the lights/switches associated with the system
All amber lights:
SERVO
LIMIT
HYD 1
HYD 2
2 Switches:
ACCU TEST
Yaw Servo Hyd Switch
Where is the Yaw Servo Hyd Switch Solenoid located?
On the transmission deck after of the oil reservoir
What’s the purpose of the double distributor valve?
Removes the possibility of a single slide valve seizure
Describe the operation of the coaxial rotary valves
Main distributor valve
Secondary back-up distributor valve
Recessed balls that compress the coil spring activating the microswitch SERVO light
Purpose of the Servo Test before start
Ensures all the secondary valves have been displaced and are free to move
Purpose of the Servo Test after start
Tests the servo light circuit continuity
Purpose of the limit system
Provides awareness to an impending Hyd Servo Reversibility / Transparency
Which system provides Hyd pressure to the TR servo
Only the Hyd 2 system
Describe the TR hyd servo system
Single Cylinder
Pressurized by Hyd 2 pump
Can be depressurized with the collective mounted Yaw Servo Hyd Switch
NOT connected to the SERVO or LIMIT caution systems
What are the two types of servo actuator options for the TR?
Samm
Dunlop
Whats the difference between the Samm and Dunlop servo actuators?
The Dunlop incorporates a system to eliminate the input lever play in case of loss of hydraulic pressure
Taking up the input play improves control in manual mode
Purpose of the Yaw Load Compensator
Assists the pilot with TR Control during a loss of hydraulic pressure
- favors right pedal
- depressurized using the “ACCU TST” button for emergency situations or post-flight procedures
What does the ACCU TST switch do
Depressurizes and/or tests the Yaw Load Compensator
How is the yaw load compensator accumulator kept charged in a pressure loss state?
- non-return valve in the pressure circuit
- pressure relief valve set to 55bar
- solenoid valve always closed and opened by the pilot
Under what conditions does Sup 28 for increased internal max gross weight apply?
High landing gear
Dual Hyd system
