Transcript CH-47D Auxiliary Power Unit

CH-47D Auxiliary Power
Unit
Terminal Learning Objective (TLO)
 Action:
Describe components, operational
characteristics, functions, restrictions and limitations
of the CH-47D Auxiliary Power Unit (APU)
 Condition:
 Standard:
In a classroom, given a student handout
Correctly answer in writing, without
reference, three of four questions, pertaining to
Components, Operational Characteristics ,
Limitations, Functions, and Malfunctions of the CH47D APU, In Accordance With (IAW) TM 1-1520-24010 and the student handout
Terminal Learning Objective (TLO) (Cont)

Safety Requirements: None
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Risk Assessment: Low
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Environmental Consideration: None
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Evaluation: Each student will be evaluated on
this block of instruction during the 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 (LSA) #1
1. Describe operational characteristics, of the
Auxiliary Power Unit (APU) Components
General Characteristics
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Model T-62T-2B
Manufactured by
Turbomach
Consumes 90 PPH
Rated Power 95 SHP
Weight 74.8 W/O
Generator
Single stage centrifugal
compressor/PT
Mounted at Sta. 600 Above
the ramp
APU Mounting Points
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Mounts: Two forward and two rigid links
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APU to rotate down
Provide: Vertical and lateral support
APU System Components
Motor/Pump
APU Start Accumulator
APU Start Module
APU
Generator
Overhead
Panel
Auxiliary Power Unit
APU Fuel Shutoff Valve
Master
Caution
Panel
APU Fault
Relay
APU Electronic Sequence
Unit
APU Fuel Boost Pump
Solenoid Valve
APU Assembly
Learning Step/Activity (LSA) #2
1. Describe Principles of Operational for the APU
Sections of the APU
Power Turbine Assembly
Reduction Drive Assembly
Air Inlet, and Compressor
Assembly
Compressor Section
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Type: Single stage centrifugal-flow (impeller)
 Air drawn in through the inlet
Combustor Assembly
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Provides: Intake of ambient air to the compress
Protects: APU against FOD ingestion
Power Turbine Section
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Type: Impeller turbine rotor
Secured: Aft end of the turbine assembly
Reduction Gear Assembly
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Purpose: Reduces power turbine shaft rotational speed
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Three mounting pad
APU Start Accumulator
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Mounted: Sta.555 R/H Ramp Area
Purpose: Stores Hydraulic Fluid
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APU Start
Emergency Use:
 Utility Sub-System
Indicator: 3,000 PSI
APU Start Module
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Located:
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Directs:
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Signal Pressure
APU Accumulator
Controls:
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Sta.584 R/H side ramp
area
Operating Mode:
 APU Motor/Pump
Indicator:
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3,000 PSI
APU Motor/Pump
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Mounted:
 Forward Portion APU
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Function:
 Motor
 Drives APU
(Starting)
 Pump
 Supplies 3350 PSI
 Engine Starters
 Utility Sub-Systems
Airframe Mounted Fuel Boost Pump
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Type: Rotary vane pump
Supplies: 7−40 PSI to the APU driven fuel pump
 Energized:
 APU start switch RUN position
Pressure Fluid Filter
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Type: Paper filter element
Mounted: Top of the reduction drive assembly
APU Fuel Control
Fuel Manifold
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Constructed: Metal fuel line
 Six bosses equally spaced
Start Fuel Nozzle Assembly
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Mounted: Combustor housing at approx. 7 O’clock
position
Purpose: Sprays fuel directly in front of the spark plug
APU Electrical System
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Battery Switch
 Two position
APU Switch
 Three position
APU GEN switch
 Two position
Magnetic Pickup
Ignition Exciter Box
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Mounted: Upper R/H
side of the turbine
Purpose: Convert DC
input to high energy AC
Event/Time Meter
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Purpose:
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Tracks starts on the rotor assembly
Tracks APU operational time
APU Oil System
Oil Sump
Oil Filter
Oil Pressure Switch
Manual Shutoff Valve
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Located: Sta.540 L/H side of ramp area
Purpose: Shut down the APU during an emergency
Electronic Sequence Unit (ESU)
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Located: Sta.585 L/H side
Purpose:
 Sequences the start procedure of the APU
 Continuously monitors the APU operation
Contains: Four BITE latches for fault indications
BITE Information
New Modification (ESU)
Learning Step/Activity (LSA) #3
1. Describe Start Procedures, Operational
Restrictions and Emergency Procedures of
the APU
Start Procedures
Start Procedures
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Three Positions Switch
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Off
Run
Start
Place switch to RUN
for 3-5 seconds
Move switch to START
for 2 seconds and
release to RUN
Master Caution/Advisory Panel
APU Operational Restriction
Tail in the wind!!!
APU Exhaust
The APU shall not be
started with a tail wind
in excess of 25 knots
Pg: 9-1-22
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Emergency
Procedures
APU Fire
APU switch – OFF.
ABORT START.
Check On Learning
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What two components are driven by the APU?
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How long should you wait before attempting a restart
on the APU?
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1 Minute
If the APU ON caution light fails to comes ON, what
should you do?
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Motor/Pump and Generator
Record the BITE information on 2408-13
What is the maximum tailwind for starting the APU?
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25 knots
Summary
Have a nice day
and
Safe Flying!