CH-47D Environmental Systems

Hot Environment

Cold Environment

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 1-1520-240-10 and the student handout

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

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

Heating and Ventilation System -Schematic

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

Heat Distribution − Components

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

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

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

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

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

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

Heater Fuel Supply Line Fuel Control Main Fuel Supply Line Heater Fuel Supply Line Fuel Control Unit

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

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

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

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

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

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

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

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

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

Normal Operation − Starting Inlet and outlet covers — Remove BATT switch — ON APU — Start (Para. 8-2-18) 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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)

Any Question?

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

Summary

Think Safety!