Flight Control Hydraulic System

Question 1

Flight Control
System

Answer 1

• Convert pilot mechanical inputs into hydraulic inputs to the rotor
• Two identical systems, No. 1 and No. 2 system. Hydraulically separated and electrically integrated
• Each system can provide the fluid to operate one of the pistons on each of the 4 dual boost actuators and half of each of the 4 ILCSs

Question 2

Hydraulic Fill
Module

Answer 2

Same as the Utility one

Question 3

Flight control hydraulic
reservoir cooler and fan

Answer 3

• No. 1 located in the fwd
  pylon area
• No. 2 located in the aft
  pylon area
• Stores and cools the
  hydraulic fluid
• The cooling fan aids air
  flow through cooler when
  hydraulic fluid temp reaches 63 degrees C and turns off when temp reaches 54 degrees.

Question 4

Power Transfer Unit (PTU)

Answer 4

• No. 1 located in the forward
  pylon area
• No. 2 located in the aft
  pylon area
• Provides hydraulic pressure
  to the No 1 or No 2 system
  during ground operations
  and when rotors are not
  turning.
• Can be used during flight
  for emergencies.
• Motor side is operated by
  the utility system and is
  connected mechanically to
  the pump side by a shaft.

Question 5

No. 1 flight hydraulic pump

Answer 5

• Located on the bottom of
  the forward transmission
• Provides the hydraulic
  pressure to the No. 1 system
  once the rotors are turning
• Can vary the flow rate of
  fluid based on the demand
  of the system

Question 6

No. 1 and No. 2 Power Control module

Answer 6

• No. 1 located in the forward
  pylon area
• No. 2 located in aft pylon
  area
• Filters, monitors, and
  controls the fluid pressure
  for the respective system
• Filters and controls the
  return fluid for the
  respective system
• An accumulator is mounted
  on the pressure side to store
  fluid for high peak demands
  and to dampen fluid
  pressure surges

Question 7

No. 1 lower control pressure
control module

Answer 7

• Located on the left upper
  side of the flight control
  closet
• Reduces the No 1 fluid
  pressure from 3000 psi to
  1500 psi for ILCA
  operation
• Routes fluid to the boost
  and extensible link portion
  of the ILCA
• Extensible link portion
  receives hydraulic
  fluid/pressure when the
  AFCS select switch is
  turned on

Question 8

No. 2 flight
hydraulic pump

Answer 8

• Located on the No 1 side
  (left) of the aft transmission
• Provides the hydraulic
  pressure to the No. 2 system
  once the rotors are turning
• Can vary the flow rate of
  fluid based on the demand
  of the system

Question 9

No. 2 lower
control pressure
control module

Answer 9

• Located on the forward side
  of the flight control closet
  on the bulkhead.
• Reduces the No. 2 fluid
  pressure from 3000 psi to
  1500 psi for ILCA
  operation
• Routes fluid to the boost
  and extensible link portion
  of the ILCA

Question 10

Integrated Lower
Control Actuators
(ILCAs)

Answer 10

• Hydraulically assist the
  pilots, prevent flight control
  feedback, and allow for
  AFCS inputs to be put into
  the flight controls.
• Upper portion is the No. 1
  portion. Lower portion is
  the No. 2 portion.
• 4 ILCAs, one for each
  access
• All have a boost actuator,
  only Pitch, Roll, and YAW
  have extensible links.

Question 11

Dual Boost
Actuators

Answer 11

• One pivoting and one
  swiveling actuator is
  located in each pylon area.
• Each actuator is mounted to
  the swashplate and will
  hydraulically move the
  swashplate based off inputs
  received from the pilots
  and/or the AFCS.
• Each actuator has two
  pistons, one for No. 1
  system and one for No. 2
  system.