Engine System Flashcards
Top Left: Forward Mounts
Bottom Left: Drag Strut (or drag brace)
Right: Aft Mount
The engines are mounted externally on each side of the aft pylon.
(5) The engine uses a three-point mounting system, two on the forward end and one on the aft end.
(a) The Forward Mounts support the engine laterally and allow for proper alignment of the engine transmission to the combining transmission.
(b) The Aft Mount is an adjustable link.
1. The link is labeled with an arrow indicating proper installation direction with the adjustable rod ends being Safetied.
2. The link is adjusted to ensure proper alignment of the engine drive shaft to the combing transmission.
(c) The Drag Strut provides forward support and holds the forward mounting structure in the case of a hard landing.
Engine Major Sections of the are designed to form a reverse annular flow path for air and hot gases
(1) Intake section allows air to be drawn into the engine.
(2) Compressor section is where air is compressed to a high state for engine operation.
(3) Combustor section provides a area for rapidly expanding gases.
(4) exhaust section allows high temperature gases to be expelled from the engine
Oil Filler Cap assembly.
(a) Allows servicing of the engine oil tank.
(1) The filler cap at the 12 o’clock position, just forward of the starter drive assembly.
(b) During preflight check for security and the tab is positioned aft, and down.
Engine oil tank located in the very front and centered on the inlet housing.
(a) Provides a mounting point for engine transmission.
(b) Stores approximately 12 quarts of oil for engine operation.
Oil level Indicator mounted on the left side of the inlet housing at the 9-o’clock position.
(a) Provides visual oil level indication for the engine.
Ambient air temperature sensor (T1 Sensor) located on the left side of the Inlet housing 10 o’clock position.
(a) Supplies ambient air temperature data to the engine ECU.
Power Turbine Speed (NP) sensor assembly, located at the 8 o’clock position of the intake section.
(a) Provides engine NP speed indication to ECU and Common Avionics Architecture System (CAAS).
Engine CHIP detector located at the 6 o’clock position on the bottom of the intake section.
(a) Provides engine chip indication to CAAS and the Maintenance panel.
Engine CHIP detector located at the 6 o’clock position on the bottom of the intake section.
(a) Provides engine chip indication to CAAS and the Maintenance panel.
Hydraulic engine starter is mounted on the starter drive pad at the 12 o’clock position of the engine compressor section.
(a) Drives the compressor section (NG) and the accessory gear box (AGB) fluid pumps during engine start
The Main Fuel Filter mounts on a bracket on the left side of the compressor housing.
(a) The main fuel filter removes contaminants from fuel prior to delivery to the HMA
Starting Fuel Solenoid Valve, mounts on bracket on left side of compressor housing at the Nine o’clock position.
(a) Delivers fuel to the combustor during the engine start sequence.
The hydro mechanical metering assembly (HMA) located on the left side of each engine lower compressor section.
(a) Made up of two unit’s fuel pump unit (FPU) and the Hydro mechanical unit (HMU), this is each engines main fuel control unit.
Two pneumatic air supply ports located at the 11 and the 9 O’clock position of the front of the combustor section of the engine.
(a) Ports pneumatic air for some component operation and FADEC engine monitoring.
Four spark igniters positioned on the cardinal positions 12, 3, 6, and 9 o’clock positions of the combustor section of the engine.
(a) Provides high temperature spark during engine start to ignite fuel.
2 Half-moon shaped fuel manifolds located on the aft end of the combustor housing.
(a) Holds the main fuel nozzles mounted on the back side of the combustor housing.
Engine fire shield bolted to the aft end of the combustor housing.
(a) Supports engine cowling and separates the combustor section and exhaust section of the engine.
PTIT bus bar assembly Mounted on the aft end of the engine fire shield.
(a) Provide engine temperature data via the ECU to the cockpit MFDs and displayed in degrees centigrade.
Engine Oil Pressure Transmitter mounted on the engine deck just below the combustor section of the engine.
(a) Provides engine oil pressure data to the ECU and CAAS.
Torque Junction Box mounted on the right aft side of Intake section 3 O’clock position.
Connects internal engine torque components to airframe mounted torque components.
The oil temperature transmitter located on the right side of the (AGB) assembly.
(a) Measures the temperature of the engine oil and supplies this information to the MFDs.
The Main Oil Filter mounts onto the bottom right side of the accessory gearbox (AGB) assembly.
(a) Filters the oil for the entire engine system.
A bleed band actuator assembly is mounted on the 6th stage of compression, 2 o’clock position right side of the compressor section of each engine.
(a) Utilized to keep air flow through compressor section of the engine stable.
Ignition Exciter box and coil-cable assembly mounts on brackets secured to the top right side of the compressor housing.
(a) Provides high voltage spark to the four spark igniters.
Liquid to liquid (Oil) cooler (heat exchanger) mounted on the right side of the engine at the 3 o’clock position.
(a) Cools the engine system oil and warms the fuel.
Oil flow programming valve mounted on a bracket on aft end of the liquid to liquid (oil) cooler left side of the compressor section of the engine.
(a) The oil flow programming valve mechanically adjusts the oil flow of the engine system.
The In-line Fuel Filter is mounted at the Two O’clock position on each engine’s compressor section.
Filters fuel before fuel reaches the combustor.
Engine driven fuel pump mounts on the accessory gearbox assembly right side of the engine compressor section.
(a) Pumps fuel to the engine when main fuel tank boost pumps fail.
The main oil pump and magnetic NG speed sensor mounts on the aft end of the accessory gearbox assembly at the 6 O’clock position in the compressor section of the engine.
(a) Pumps oil through the oil system from the oil reservoir.
(b) The NG speed sensor provides the NG speed signal to the CAAS for display on the MFD’s.
The over speed solenoid valve mounted on the right side 4 O’clock of each engine compressor section.
(a) In an event of engine over speed condition the valve will restrict fuel to slow the engine down.
Dual element chip detector mounted at the 5 O’clock position of the compressor section of the engine.
Monitors hot end internal bearings for excessive wear or failure.
fuel flow divider mounted on the bottom of each engines combustor housing 6 o’clock position.
(a) Divides fuel between the two half-moon shaped fuel manifolds.
Combustor drain valves assemblies mounted on the bottom of each engines combustor housing 6 o’clock position.
Drains excess fuel from engine combustor.
The Torquemeter System consists of the engine Internal Torque components, Torquemeter Junction Box, and Ratio Detection Power Supply (RDPS).
(e) The Internal torque components, creating an electrical torque signal.
- The electrical signal is sent to the Junction Box through the electrical connector.
- The Junction Box signals are transmitted to the RDPS and are used to generate the torque indications in the cockpit.
- Two RDPSs are mounted in the aft cabin ceiling left and right side for #1 and #2 engines.
- Each RDPS processes the electrical torque signals received from the junction box and routes signals proportional to engine torque signal to the ECU for engine performance monitoring and to the cockpit MFD indicators.
The Torquemeter System consists of the engine Internal Torque components, Torquemeter Junction Box, and Ratio Detection Power Supply (RDPS).
(e) The Internal torque components, creating an electrical torque signal.
- The electrical signal is sent to the Junction Box through the electrical connector.
- The Junction Box signals are transmitted to the RDPS and are used to generate the torque indications in the cockpit.
- Two RDPSs are mounted in the aft cabin ceiling left and right side for #1 and #2 engines.
- Each RDPS processes the electrical torque signals received from the junction box and routes signals proportional to engine torque signal to the ECU for engine performance monitoring and to the cockpit MFD indicators.
- There are five Thermocouple Harness Assemblies in the PTIT Indicating System.
- The probes insert into, and mount just prior to the first NP power turbine disk, (inlet to the power turbine section).
- The average of these Thermocouple Harness Assemblies at the PTIT Bus Bar Assembly is sent via the DECU/ECU to the cockpit MFDs and displayed in degrees centigrade.
- There are five Thermocouple Harness Assemblies in the PTIT Indicating System.
- The probes insert into, and mount just prior to the first NP power turbine disk, (inlet to the power turbine section).
- The average of these Thermocouple Harness Assemblies at the PTIT Bus Bar Assembly is sent via the DECU/ECU to the cockpit MFDs and displayed in degrees centigrade.
Power Turbine Speed Indications (NP).
(a) No. 1 and No. 2 Engine Power Turbine (NP) are displayed on the MFD Instruments page, using digital readouts and temperature tapes.
(b) The signal for the indication is provided by the NP speed sensor located at the 8 o’clock position mounted on the accessory gearbox (AGB).
(c) Power Turbine Speed, NP Sensor consists of two identical speed sensors which function like the speed sensor for the NG indicator on the back of the oil pump and are used in conjunction with the fuel overspeed solenoid valve.
(d) Each channel operates using separate pickups NP_A and NP_B that allows for NP load shear information for the ECU’s.
The engine oil pressure indicating system measures the pressure of oil circulating within the engine, and then supplies this information to the cockpit to provide a digital readout of engine oil pressure on the MFD instruments/power train page.
(a) The primary component of this system is the Oil Pressure Transmitter which is mounted on the airframe, below each engine near the aft engine mount.
(b) The transmitter sends signals to the DCUs which then supply the signals to display the engine oil pressure on the cockpit MFDs.
When engine oil pressure is equal to 5 psi or greater, but less than or equal to 90 psi, Indication is green.
- When engine oil pressure is greater than 90 psi but equal to or less than 110 psi indication is yellow.
- When engine oil pressure is below 5 psi or greater than 110 psi, the indication is red.
- ENG1 OIL PRESS HI and/or ENG2 OIL PRESS HI Cautions indicate that the ENG oil Pressure is greater than 90psi.
ENG1 OIL PRESS LO and/or ENG2 OIL PRESS LO Cautions indicate that No. 1 and/or No. 2 engine oil pressure is less than one of the following: 5 psi between 48 to 80% NG, or 32 psi between 80 to 95% NG, or 50 psi above 95% NG.
(2) The Engine Oil Temperature digital readouts are displayed on the on the Instruments/Power Train page.
The Oil Temperature Transmitter located on the right side of the AGB measures the temperature of the engine oil, and supplies this information to the cockpit through the DCUs to provide a digital readout of engine oil temperature on the MFDs.
The maximum oil temperature is 149°C.
- When engine oil temperature is less than or equal to 149°C the engine oil temperature digital readout is displayed in green.
- When engine oil temperature is greater than 149°C the digital readout is displayed in red and the ENG1 OIL HOT and ENG2 OIL HOT cautions are displayed on the MFD.
Engine CHIPS Annunciation colors
The Engine CHIPS Caution when activated is displayed on the on the Instruments/Power Train page on the MFD’s and the power train section of the Maintenance Panel mounted on the right side wall of the ramp area.
Engine CHIPS Annunciation colors:
- CHIPS - Displayed in red on MFD power train Page and yellow on the Maintenance panel.
- ENG1 CHIPS and ENG2 CHIPS Cautions Indication on the MFD’s and the Maintenance Panel is supplied by Engine chip detector mounted at the 6 O’clock position on the bottom of the accessory gear box.
The Chip Detector magnet attracts ferrous particles, when a ferrous particle breaches the positive post and the grounded housing, it will close the circuit connected through the fuzz burn-off module, the corresponding DCU, and to the associated indicator on the MAINTENANCE PANEL.
Power Plant 714 Description
The CH-47F is powered by two T55-GA-714A engines
(1) The engines are housed in separate nacelles mounted externally on each side of the aft pylon.
(2) Each engine has an engine transmission mounted on the forward end which provides the transition of power to the combining transmission.
(3) A Full Authority Digital Electronic Control (FADEC) system automatically controls engine operation throughout the full operating range of the engine.
What is the model of the power plant used in the CH-47F?
T55-GA-714A
The T55-GA-714A is a turbine engine manufactured by Honeywell.
What does IERW stand for in the context of CH-47F training?
AQC
IERW refers to the International Education and Readiness Workshop.
What are the enabling learning objectives (ELO) for the training on CH-47F T55-GA-714A?
Identify aspects of CH-47F T55-GA-714A power plant and engine controls system
Students are expected to understand the system’s general description, purpose, and functions.
What safety procedure should Soldiers follow during a fire emergency?
Exit the classroom in an orderly manner; the last one out closes the door
Soldiers must meet at a designated location for accountability.
What environmental considerations must be adhered to during training?
Comply with all environmental laws and regulations
This includes federal, state, and local regulations as outlined in TC 3-34.489.
Identify the type and series of the power plant used in CH-47F.
Type: Turbine, Series: 55
The engine is designated as T55-GA-714A.
What automatic system controls engine operation in the CH-47F?
Full Authority Digital Electronic Control (FADEC) system
FADEC manages engine performance throughout the operating range.
What are the four main sections of the T55-GA-714A engine?
Intake / Compressor / Combustor / Exhaust
These sections represent the fundamental components of the engine’s function.
What does the acronym ‘NG’ refer to in the context of the T55-GA-714A engine?
Gas Generator Speed
NG is a critical performance indicator for the engine.
What should be checked during Pre-Flight Inspections?
Main Fuel Filter / In-line Fuel Filter / Main Oil Filter
These filters are essential for ensuring engine performance and safety.
What does an NG over speed indicate?
Above 111%
An NG over speed can lead to engine over-temperature and over-torque.
What are the color indications for oil pressure digital readouts?
- Green: Oil Press > 5 psi and < 90 psi
- Yellow: Oil Press > 90 psi and < 110 psi
- Red: Oil Press < 5 psi and > 110 psi
These colors help in diagnosing engine oil pressure issues.
What are the engine torque limits for the T55-GA-714A?
100% Dual Engine / 123% Single Engine
These limits are crucial for maintaining engine integrity during operation.
What happens when the Engine Condition lever is placed at STOP?
Engine shutdown occurs
This is a safety feature to prevent engine damage.
What does the PTIT indicating system measure?
Power Turbine Inlet Temperature
PTIT is critical for monitoring engine temperature during operation.
What are the FADEC primary features?
- Power Assurance Test
- Twin Engine Load Sharing
- Power Turbine Speed Governing
- Transient Load Anticipation
- Surge Avoidance
These features enhance engine performance and reliability.
What is the purpose of the Engine Chip Detector?
To detect metal particles in the oil, indicating wear or failure
This is vital for engine maintenance and safety.
What is the risk assessment level mentioned in the training?
Classroom/building fire or severe weather with high wind damage
This risk assessment is crucial for ensuring student safety.
What are the safety requirements for the training environment?
Fire/Inclement briefing and evacuation/shelter plan
Ensuring safety protocols are in place is essential for all training sessions.
What is displayed on the ECU Hexadecimal display during the ECU Pre-Start, Start or Shutdown BIT checks?
ECU fault codes, type of fault, aircraft operational effect, pilot actions required, overall mission impact
Define ‘Abort Mission’.
Perform a normal engine shutdown and make appropriate entries on the DA form 2408-13-1
Define ‘Continue Mission’.
The crew may complete the present day’s mission; however, an appropriate DA Form 2408–13–1 entry is required
What action should be taken if the ECU display is other than 88?
Place the ENG COND lever to STOP, set B/U PWR switch to OFF, remove all power to the ECU by pulling the respective FADEC PRI CONT and REV CONT circuit breakers on the PDP
What does a failed fixed condition signify?
The engine remains at the power level being used at the time of the failure and is unaffected by thrust control lever inputs
What are the classifications of ECU faults?
- Soft Faults
- Hard Faults
What is a Soft Fault?
A failure that does not impact the normal control of the engine and is not indicated in the cockpit
What is a Hard Fault?
Faults that could cause unacceptable engine and/or aircraft performance and are detected through software fault limit monitoring
What must be checked for cold weather starts?
Engine oil pressure for 5 psi minimum on power train page
What oil types are used for the T55-GA-714A engine?
- MIL-L-23699 (Green Can) for temps above -32°C
- MIL-L-7808 (Silver Can) for temps below -32°C
What happens if oils are mixed in the T55-GA-714A engine?
The system must be flushed within six hours of operation, an oil sample taken, and a DA Form 2408-13-1 entry is required
What are the five features of the Hydro Mechanical Metering Assembly (HMA)?
- Fuel Pump Unit (FPU)
- Hydro Mechanical Unit (HMU)
- NG speed sensor
- Three Phase alternator
- Main Metering Valve
What is the purpose of the Bleed Band Actuator Assembly?
Facilitates compressor rotor acceleration, prevents compressor stall, reduces engine system surges
What is the Power Assurance Test (PAT)?
Performed to establish if the engines will provide the required power for flight for the predicted mission profile
What is the minimum NG speed for engine stabilization at ground idle?
50% minimum
What should be done if either engine fails to accelerate smoothly past 70% NG?
It may indicate a clutch malfunction in the engine transmission
What must be done when operating for extended periods with only one engine operating?
The second engine must be motored for 10 seconds every 30 minutes
What is the immediate action for an Emergency Engine Shutdown?
ENG COND Lever — STOP / FIRE PULL handle — Pull (as required)
What does the load share switch on the FADEC control panel allow the pilot to choose?
Engine load share
What is the maximum allowable Power Turbine Inlet Temperature (PTIT) for time-limited operation?
Above 816 PTIT
What should be checked on preflight inspection regarding engine fluid lines?
Leaks and Chaffing
What component supplies the engine oil pressure signal seen on the powertrain portion of the engine instrument page?
Oil Pressure Transmitter
What are the two types of signals provided by the component installed in the flight control closet for eliminating rotor droop?
Torque and PTIT
What is the definition of a Soft Fault?
An engine FAULT detected by the ECU that does not impact the normal control of the engine
What is the definition of a Hard Fault?
An engine FAULT that could cause unacceptable engine or aircraft performance
What should be checked on preflight regarding engine fire extinguisher bottles?
Engine fire extinguisher bottles gauges
In accordance with the chart in TM 1-1520-271-CL.
How long should you hold and release the engine start switch when starting a selected engine?
Start and hold until NG accelerates to 12%, then release switch.
Agent from one of the two engine fire extinguisher bottles can be directed to which engine?
Both Engines
What two CAUTIONS should be active before turning on the backup power switch during engine startup?
FADEC 1 and FADEC 2 ACTIVE
During a FADEC 1 or FADEC 2 failure, what switch does the pilot use to keep the engines matched in torque or PTIT?
Increase Decrease switch
What is the minimum duration of the cool down time the engines must be run with thrust at ground detent before shutting down?
Two Minutes
What is the purpose of the engine main oil filler assembly?
Filter the Oil for engine operation.
What is the purpose of the main fuel filter?
Filter the Fuel for HMA operation.
What engine indications are you looking for during a first engine start in primary mode?
Check when stabilized at ground idle (NG at 50% minimum) engine oil pressure for 5 psi minimum within 45 seconds.
After starting the first engine, the second engine must be started or motored for ___________ seconds within _____________ minutes.
10 seconds within 3 minutes
With ECL’s in flight, why should you delay turning the second generator on for 2 seconds?
Gives the ECU time to sample power without causing a soft fault.
Both EAPS fans should not be operated at the same time while using what generator for electrical power?
APU Generator
What are the engine oil pressure limitations for Minimum oil pressure, Contingency power, and cold weather starts?
5 PSI / 110 PSI / 150 PSI
What are the two functions of the liquid-to-liquid cooler?
- Cool the Oil
- Warm the Fuel for engine operation
Name the component mounted on the AGB that supplies the engine CHIP Caution signal.
Engine Chip Detector
What component on the engine meters fuel for engine operation and supplies electrical power and NG speed data to ECU’s?
HMA or HMU
Name the fuel pumps the accessory gear box (AGB) drives during engine operation.
Engine driven fuel pump and the fuel pump unit or the HMA
What are the two functions of the engine oil level indicator?
- Oil level in engine oil tank
- Provides engine low oil signal to CAAS
Name the component that provides an NG speed signal to CAAS only and name the component on the engine it is mounted on.
Magnetic NG Speed Sensor mounted on the aft end of the engine oil pump
List the externally mounted components of the engine.
- Oil Filler Cap assembly
- Hydraulic Engine Starter
- Main Fuel Filter
- Ambient Air Temperature Sensor
- Start Fuel Solenoid Valve
- Oil Level Indicator
- Oil Tank
- NP Speed Assembly
- HMA
- Chip Detector
- Spark Igniter
- Oil Pressure Transmitter
What component provides high pressure fuel for engine operation?
Fuel Pump Unit
What component meters fuel for engine operation?
Main Fuel Metering Valve
What provides electrical power to the FADEC system?
Alternator
What port is used for bleed-band operation?
P3 Bleed Port
What is the purpose of the Combustor Drain Valves?
What is the purpose of the Oil Flow Programming Valve?
What is the function of the Over Speed Solenoid Valve?
Name the component that provides an NG speed signal to ECU.
NG Speed Sensor signal
