Power Plant Flashcards
What engine is the Bell 505 power plant?
Safran Arrius 2R.
How many double-thermocouples provide temperature sensing in the engine?
Four.
How many MGT signals are fed to each ECU channel?
Two.
What caption would you expect to see if one of the MGT signals is declared failed by the ECU, and what is the action required?
- White ECU MAINT caption.
- Maintenance required prior to next flight.
What caption is triggered when both of the MGT signals are declared failed by the ECU?
A yellow ECU DEGRADED caption.
At what NG is the engine typically self-sustaining?
50% NG.
When is the electrical supply to the starter cut off?
At engine self-sustaining speed.
Where is MGT measured?
Gas generator turbine outlet.
How is torque measured?
Load through the helical teeth on the intermediate gear cause causes the torquemeter piston to change the value of modulated pressure supplied to the torque transmitter.
What caption would you expect if the torque signal was declared failed by the ECU?
A yellow ECU DEGRADED caption.
How is NP measured?
Two magnetic sensors located on the forward gearbox at the NP intermediate gear shaft.
What caption would you expect if one of the NP signals is declared failed by the ECU?
A yellow NP SENSOR FAIL caption.
What caption would you expect if both NP signals were declared failed by the ECU?
A red ECU FAIL caption.
What is the meaning of the white ECU DATA caption?
ECU data input to the Integrated Avionics Unit has failed.
What are the two functions of the NG alternator (the PMA)?
- Primary source of electrical power to the ECU.
- Provides NG acquisition signal.
What caption would you expect if one of the NG acquisition signals fails?
A white ECU MAINT caption.
What caption would you expect to see if both NG acquisition signals are declared failed while during start or at idle power?
A red ECU FAIL caption.
What two things happen if both NG acquisition signals are declared failed while in-flight?
- The ECU reverts to an alternate law.
- A yellow ECU DEGRADED caption shows.
Below what engine oil pressure will the red ENG OIL PSI LOW caption appear?
25psi.
Above what engine oil pressure will the yellow ENG OIL PSI HI caption appear?
217psi.
From what material is the engine compressor wheel made?
Titanium
What type of compressor does the engine have?
Single-stage centrifugal
What is the compression ratio of the engine compressor?
9:1
At what Ng is the engine considered to be self-sustaining?
50%
How is Np measured?
A phonic wheel in the accessory gearbox with two magnetic speed sensors.
**What are the limitations on the starter when starting the engine?
50 seconds ON
30 seconds OFF
50 seconds ON
30 MINUTES OFF
What systems does the engine accessory gearbox drive?
HP Fuel Pump
LP Fuel Pump
Oil Pump
Alternator/Ng Sensor
Centrifugal Breather
Starter/Generator
Where is the engine accessory gearbox?
In the engine - Module 1
What type of combustion chamber does the engine have?
Reverse-flow annular.
How many igniters does the engine have?
Two
What type of turbine does the gas generator have?
Single stage with single-crystal inserted blades
What type of turbine is the power turbine?
Single stage, axial flow with directionally solidified blades
How many actuators (stepper motors) is the fuel metering valve equipped with?
Two
What are the two functions of the dual-channel Permanent Magnet Alternator (PMA)?
- ECU power
2. Ng acquisition signal
When will an in-flight relight occur?
When the CSS detects an engine flame-out
In the event of a failure of both stepper motors, or the seizure of the fuel metering needle, what controls fuel flow?
The ACU
How does the ACU work?
By actuating the bypass metering valve
What must the pilot guard against if the ACU is active?
Large or abrupt power changes
What caption is associated with the activation of the ACU?
The Yellow HMU AUX CTRL caption
What caption is associated with a complete failure of the fuel metering system?
A Red ECU FAIL caption
What logic governs the degradation of the ECU?
- If the failure does not affect the main control law, the ECU will continue using the main control law.
- If the affects the main control law, the ECU will use the back-up law.
- If both the main and back-up laws are affected, the system will freeze the stepper motor
What are the three levels of ECU failure indications?
- Red ECU FAIL caption
- Yellow ECU DEGRADED caption
- ECU MAINT advisory caption
What is the effect of the ECU ability to control fuel flow in the event of a Red ECU FAIL caption?
ECU is unable to control fuel flow
What is the effect of the ECU ability to control fuel flow in the event of a Yellow ECU DEGRADED caption?
Fuel governing is affected and engine performance is degraded
What is the effect of the ECU ability to control fuel flow in the event of a ECU MAINT advisory caption?
No effect on engine governing
What is the urgency of the need to land associated with the Yellow IBF CLOGGED caption, and how is it modified?
Land as soon as practical if you can clear the conditions which led to clogging
If you cannot clear the conditions which led to clogging, Land AS SOON AS POSSIBLE
How many fire detectors are there in the engine bay and where are they located?
Three. Two in the hot zone and one in the cold zone
Where is the engine oil filter pre-blockage pop-out indicator?
Upper forward left side of the engine, on the pump filter support block
What does the engine oil filter pre-blockage pop-out indicate?
- Impending engine oil filter blockage. Maintenance is required
How many electrical magnetic plugs protect the engine oil system?
Two
What caption would you expect associated with a Yellow ENG CHIP caption after landing?
ENG CHIP 1 or ENG CHIP 2 advisory caption after WOG is activated
What is the urgency of the need to land associated with the Yellow ENG CD INOP caption?
Land as soon as practical
Does the CHIP TEST feature on the ENGINE TEST page monitor the engine chip detectors?
No
Under what conditions can lubricants other than those MIL-PRF-23699 or MIL-PRF-7808 be used in the engine?
Only with the approval of SAFRAN
How many levels of fuel blockage are monitored?
Two levels of fuel pre-blockage prior to the blockage bypass opening
What methods are there to detect pre-blockage?
Two pressure transmitters and a bypass indicator
What warnings does the fuel pre-blockage detection system activate?
Level 1 - FUEL FILTER advisory caption after shutdown
Level 2 - Yellow FUEL FILTER caption
What is the urgency of the need to land in the event of a Yellow FUEL FILTER caption?
Land As Soon As Practical
What indications are triggered when the fuel filter bypass activates?
Fuel filter bypass pop-out
Where is the fuel filter bypass popout located?
Port side of the engine, forward of the fuel filter housing facing up
What does the Red FUEL PRESS caption mean?
The fuel pressure has dropped below the value deemed viable by the ECU based on fuel temperature and atmospheric pressure
What does the preference injector valve do?
Closes fuel to the nine main injectors during rapid power decrease, but maintains flow to the preference injector to prevent flame-out.
What does the start electro-valve do during start, and during normal running?
- During start, it delivers fuel to the start injectors.
- During normal running, it purges the start injector using P3 bleed air, to avoid blockage of the start injector with carbon.
