Term
| What engine is installed on the AH-64D? |
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Definition
What engine is installed on the AH-64D?
The GE 701 D/CC |
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Term
| Which type of engine, DECU and HMU are installed in a 701 D/CC? |
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Definition
Which type of engine, DECU and HMU are installed in a 701 D/CC? The 701D/CC is defined as a 701D core engine
controlled by a 701C HMU and DEC. The
701D/CC maintains all of the features of the
701C with durability improvements to the hot
section.
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Term
| Are 701C performance charts valid for use with a 701-D/CC configuration? |
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Definition
Are 701C performance charts valid for use with a 701-D/CC configuration? Yes. Engine performance is the same between the
701D/CC and the 701C. Therefore, performance charts used with the 701C are also valid for the 701D/CC.
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Term
How many modules make up the 701C engine?
What are they?
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Definition
How many modules make up the 701C engine? Four
What are they? Cold section, hot section, power turbine
section, and accessory section.
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Term
What is the power rating of the 701C?
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Definition
What is the power rating of the 701C?
1800 SHP IRP (30 minute limit)
1890 SHP MAX (10 min limit)
1940 SHP continuous (2.5 minute limit)
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Term
| Which section houses the sensors for TGT, torque and overspeed and Np? |
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Definition
Which section houses the sensors for TGT, torque and overspeed and Np? Mounted on the power turbine module is
the thermocouple harness, the torque and overspeed
sensor, and the NP sensor.
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Term
| How many mounts keep the engine secured to the airframe? |
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Definition
How many mounts keep the engine secured to the airframe? Two, primary and secondary. The secondary mount is designed to continue to support the engine in the event of a primary mount failure.
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Term
| How many sections within the cold section module? |
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Definition
How many sections within the cold section module? Three: inlet, compressor, diffuser
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Term
How is Np overspeed protection provided?
At what Np does overspeed protection occur?
How is Np overspeed protection put into effect? |
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Definition
How is Np overspeed protection provided? By the DECU
At what Np does overspeed protection occur? 119.6 +/- 1
How is Np overspeed protection put into effect? The DECU sends an overspeed signal to the ODV, which stops fuel flow to the injectors. |
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Term
| In which section does actual combustion occur within the engine? |
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Definition
In which section does actual combustion occur within the engine? Within the hot section
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Term
In which section does the torque reading come from?
How is torque calculated?
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Definition
In which section does the torque reading come from? The power turbine section
How is torque calculated? Torque is calculated by referencing the amount of twist between the Power Turbine driveshaft and the torque sensor reference tube.
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Term
| Where are the Power Turbine Shaft and torque sensor reference tube pinned together? |
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Definition
Where are the Power Turbine Shaft and torque sensor reference tube pinned together? They are pinned together at the front, where the force to turn the gearbox and transmission is actually applied.
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Term
| Where does the power turbine section drive the Power Turbine Driveshaft? |
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Definition
Where does the power turbine section drive the Power Turbine Driveshaft? At the AFT end of the driveshaft. The force is then transferred forward through the driveshaft to the gearbox/transmission.
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Term
| Where does the Np reading come from? |
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Definition
Where does the Np reading come from? The Np reading is taken at the aft end of the Power Turbine Driveshaft in the power turbine section.
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Term
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Definition
What is Np? Np is the RPM at which the engine is rotating, which is displayed in an easier-to-read % format. Np is usually compared to/referenced along with Nr (rotor RPM) to determine the current performance of the engine, especially during troubleshooting. Generally, Np and Nr should match during normal operation.
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Term
| What is the purpose of the accessory section? |
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Definition
What is the purpose of the accessory section? The accessory section module provides mounting for engine-driven accessories and provides for engine starting.
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Term
How is the accessory section driven?
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Definition
How is the accessory section driven? The accessory section module is driven by the radial driveshaft, which is driven by the compressor rotor PTO gear. So:
Compressor rotor ---> PTO gear ---> Radial driveshaft ----> Accessory section ---> Accessory components
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Term
What drives the Air Turbine Starter (ATS)?
What does the ATS drive to allow starting?
How does this occur?
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Definition
What drives the Air Turbine Starter (ATS)? IPAS air from the APU to the ATS PRSOV.
What does the ATS drive to allow starting? The ATS drives the compressor section
How does this occur? Via the radial driveshaft
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Term
What is the purpose of the Inlet Particle Separator (IPS)?
How is the IPS driven?
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Definition
What is the purpose of the Inlet Particle Separator (IPS)? The IPS provides separation of foreign particles from the inlet airflow to protect the engine from erosion and damage
How is the IPS driven? The IPS is driven by the accessory section at 22,000 RPM at 101%
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Term
Once Np overspeed protection is enabled, where does the excess fuel go?
Is Np overspeed protection a destructive or non-destructive event?
What must be present to provide Np overspeed protection? |
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Definition
Once Np overspeed protection is enabled, where does the excess fuel go? Remaining fuel is diverted back to the HMU.
Is Np overspeed protection a destructive or non-destructive event?
Np overspeed protection is non-destructive.
What must be present to provide Np overspeed protection?
The DECU must have aircraft power.
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Term
What is the HMU?
Where is it located?
What does the HMU provide? |
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Definition
What is the HMU? Hydromechanical Unit
Where is it located? Mounted on aft center of accessory module
What does the HMU provide? High pressure fuel pumping, metering, flow computation and shutoff.
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Term
Which engine component provides NG overspeed protection?
At what NG speed does this occur?
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Definition
Which engine component provides NG overspeed protection? HMU
At what NG speed does this occur? 110% +/- 2
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