1. CH-47D Environmental Systems

2. Hot Environment

3. Cold Environment

4. Terminal Learning Objective (TLO)
Action: Describe the components, operational characteristics, functions and limitations of the CH-47D Environmental Systems
Conditions: In a classroom, given a student handout
Standards: Correctly answer in writing, without reference, four of five questions pertaining to components, operational characteristics, limitations, and functions of the CH-47D Environmental System, IAW TM and the student handout

5. Terminal Learning Objective (TLO) – (Cont.)
Safety Requirements: None
Risk Assessment Level: Low
Environmental Considerations: None
Evaluation: Each student will be evaluated on this block of instruction during the third written examination. This will be a criterion type examination requiring a GO on each scored unit. You will have 90 minutes for the exam

6. Learning Step/Activity #1
Describe components, functions, and operational characteristics of the Heating and Ventilating system

7. Heating and Ventilation System -Schematic

8. Heating and Ventilation System
Type:
200,000 British Thermal Unit (BTU)/hr
Internal combustion system
Fuel Supply:
R/H Main tank
Consumes 15 PPH
Electrical Power:
3 Phase AC
28V DC
No.2 PDP

9. Heat Distribution − Components

10. Cockpit Air Knobs Located: Purpose: Outboard – Pilot/Co-Pilot
Regulates – Air flow to the cockpit

11. OPERATOR’S MANUAL - CAUTION
Pull out the cockpit air knobs Slowly to preclude dirt and debris from being blasted into the air and the pilot’s eyes
Page: 8−4−1

12. Air Control Handles Mounted: Purpose: R/H Side – Canted console
Two handles
Purpose:
Upper handle:-
Control Defogging/Defrosting
Bottom handle:-
Direct air to the cargo compartment

13. Differential Air Pressure Switch
Heater Assembly
R/H side Sta.95 and 120
Intake Duct
Low Pressure Line
Exhaust Duct
Blower
Main Fuel Supply Line
Differential Air Pressure Switch
Spark Plug
Adapter Assembly
Fuel Control
Combustion Chamber
Ignition Unit
Drain Line

14. Heater Assembly - Components
Combustor Chamber:
Inner and outer chamber
Passes air over heated chamber and discharge - Bottom
Spark Plug:
Ignition

15. Heater Drain Combustor Drain: Sta.98 outside R/H
Drains unburned fuel overboard
Subject to ice accumulation
If the heater shuts down during icing:-
Do Not Attempt to Restart

16. Heater Fuel Supply Line
Fuel Control
Main Fuel Supply Line
Heater Fuel Supply Line
Fuel Control Unit

17. Fuel Control (Cont.) Mounted: Purpose: Supply and control fuel flow:-
R/H side in the heater compartment
Purpose:
Supply and control fuel flow:-
Main fuel tank – Boost pumps
Filter assembly
Fuel pump – Raises fuel pressure – 100 PSI
Pressure relief valve
Solenoid valve

18. Exhaust System Constructed: Heat resistant steel
Connected – Bottom heater
Enclosed:-
Four piece shroud
Protects personnel – Exhaust surface
Outside – Helicopter (check for obstruction)

19. REMOVE COVERS PRIOR TO STARTING THE HEATER
Exhaust System (Cont.)
Heater Exhaust
REMOVE COVERS PRIOR TO STARTING THE HEATER
Heater Intake

20. Ignition Unit Mounted: Purpose: Sta.95 R/H side
High voltage pulse – Spark plug
Contains: Replaceable fuse

21. Blower Assembly Mounted between: Purpose: Intake duct Heater assembly
Draws air – Intake
Blower Assembly

22. Differential Air Pressure Switch
Mounted:
Heater compartment
Purpose:
Fuel flow
Ignition:-
Insufficient air

23. Heater Controls (Overhead Panel)
Function Switch:
Three Position:-
VENT BLOWER ONLY
OFF
HEATER ON
Heater Start Switch:
Press and Release Type
Time Delay:-
10 – 15 Sec
Fuel
Ignition
Cabin Temperature Selector:
Controls cabin thermostat

24. Cabin Thermostat Located: Function: L/H side Sta.355 cabin area
With temperature selector and controller
Maintain cabin temperature pre-selected temperature:-
Mercury filled – Heated 34°C
Removes power:-
Fuel solenoid valve

25. Heater Hot Caution Light
Located: Master caution panel
Indicates: Failure automatic temperature circuits
Heater – Shuts OFF
Blower – Continue RUN

26. Normal Operation − Starting
Inlet and outlet covers — Remove
BATT switch — ON
APU — Start (Para )
APU GEN switch — ON. RECT OFF caution capsule extinguishes
R (Right) MAIN FUEL PUMP switches — ON
Heater function switch — Heater ON
HTR START switch — Press
Page: 8-4-1

27. Stopping
Heater function switch — OFF
Wait Two Minutes Before Turning Generator (s) Off
NOTE: After heating and ventilating system has been stopped with the generator (s) ON, the blower will continue to operate until the temperature within the heater combustion chamber is below 49°C degrees
Page: 8-4-2

28. Heater Overheat Condition
Wait two minutes for cool down (Heater)
HTR START switch — Press
HEATER HOT caution — Monitor
The HEATER HOT caution light will not extinguish until combustion chamber temperature is below 177°C and HTR START switch is pressed
Page: 8-4-7

29. Learning Step/Activity #2
Describe the operational characteristics and limitations of the Windshield Wipers

30. Windshield Wipers − Rotary Switch
Located:
Overhead control panel
Five Positions:
PARK
OFF
SLOW
MED
FAST

31. Wipers − Park Position Park Position: Operators Caution: NOTE:
Stowed against the inside windshield frame
Operators Caution:
To prevent windshield damage, do not operate windshield wipers when windshield is dry
NOTE:
The windshield wipers shall be off at airspeeds above 130 knots
Page: 2-9-3
Page: 5-5-1

32. Learning Step/Activity #3
Describe the operational characteristics and limitations of the Windshields Anti-Ice

33. Windshield Anti-Ice Provides: Transparent Conductive Coating Embedded:
Anti-Icing/Defogging:-
Pilot and Copilot windshield
Defogging:-
Center windshield
Transparent Conductive Coating Embedded:
Pilot
Center
Co-Pilot
Electrically heated

34. Temperature Controller
Located:
Nose compartment
Temperature Controller:
Interrupts:-
Electrical 44°C degrees – Pilot and Copilot
Center windshield – 27°C degrees

35. Operators Manual - CAUTION
If windshield bubbling or delaminating occurs around the sensor element, immediately place switch to OFF for that windshield
Page: 2-9-1

36. Windshield Anti-Ice Switches
Located: Overhead control panel
Switches: Two position
OFF ON
CPLT – Co-Pilot
CTR – Center
PLT – Pilot

37. Learning Step/Activity #4
Describe the operational characteristics and limitations of the Pitot Heat system

38. Pitot Tubes Mounted: Use: L/H (No.1) and R/H (No.2) side nose
Indicate (proper) airspeed:-
Indication – Outside (ram) air
Heat system:-
Protect against ice, rain, IMC flights and water operation
Heated – 145 watt

39. AFCS Side-Slip Ports Mounted: Consist: L/H and R/H side Upper:-
No.1 System
Lower:-
No.2 Systems
Both heated – 25 watt

40. Pitot Switch on Overhead Panel
Two position
OFF ON
Use:
IMC
Icing
Rain
Water operations
Ground limitations:
5 Min
Advise crewmember
(Page: 5-9-1)

41. Any Question?

42. Check On Learning What fuel Tank supplies fuel to the heater?
Right Main
When should Pitot Heat be used?
Rain, IMC, Ice and Water
What are the Five position on the windshield wiper rotary switch?
Park, Off, Slow, Medium and Fast
What Two items are the crewmembers required to check?
Pitot Heat and Yaw Sideslip Ports (AFCS)
What is the Airspeed Limit for the windshield wipers?
130 knots

43. Summary

44. Think Safety!