Engines + Drive Train Flashcards
What is the make and model of the engine of the aircraft?
Pratt and Whitney T400 turbo shaft engines
Each engine is flat rated to how much horsepower?
1070 shaft horsepower
What is the maximum continuous output from each engine?
916 shaft horsepower
How many axial stages does each engine have?
3
How many centrifugal stages does the engine have?
Single stage
How many power turbine stages does the engine have?
Single stage
How many fuel nozzles are in the annual or combustion chamber?
14
How many igniter spark plugs are in each engine?
2
How is the fuel control system powered?
Hydro pneumatically
How is the engine kept free from ice, dust, and other foreign objects?
Particle separators
At what engine speed will the particle separator switch close these separator door?
Ng dropping below 52 ± 2%
If the particle separator switches off what occurs to the air being ingested by the engine?
It will route all induction air into the engine and therefore exposed the engine to FOD
The particle separation door is closed via what 2 mechanisms?
If the particle separator switch is placed into off or if the respective fire handle is pulled
How is the particle separator powered?
Through the 28VDC essential bus
How is fuel warmed prior to entering the engine?
Through an oil to fuel heat exchanger system located on the front face of each accessory gearbox
Above what temperature does the oil to fuel heat exchanger cease operation?
Above 32°C
Where is the location of the engine driven fuel pump?
The front face of each accessory gearbox between the fuel control unit and the gear cover of each engine
What is the minimum temperature the oil to fuel heat exchanger warms the fuel tube prior to being introduced into the engine?
5°C
Does the engine driven fuel pump have a filter?
Yes an integrated filter is incorporated into each engine driven fuel pump
How is the automatic fuel control powered on each engine?
From a drive shaft connected to the fuel pump on each engine
When in manual throttle mode, how does the fuel control unit measure fuel to the engine?
Through manually positioning of the metering valve
How is pressure regulated inside of the engine fuel control unit?
A pressure regulated valve maintains a constant pressure at the metering valve to bypass excess fuel back to the engine pump
The primary function of the automatic fuel control system is to prevent what?
Ng and NF overspeed as well as to maintain Ng idle speed
How is the manual fuel control unit connected to the engine?
Through a direct, geared connection to the Ng section of the engine
What is the caution associated with manual fuel?
It is possible to overspeed the Ng turbine, NF turbine and to exceed maximum ITT or Q
What is the caution associated with operating an automatic fuel?
Despite being automatic it is still possible to exceed Ng, NFQ, and IT
Where is the power turbine governor located?
On the combining gearbox and is driven by its respective engine
What is the primary function of the power turbine governor?
To obtain maximum performance of the engines with a minimum of attention
What is the engine design droop without the droop compensator?
12% RPM
How does the droop compensator work?
When collective is increased, the droop compensator moves the NF governor lever which increases the P3 air pressure. This causes the automatic fuel control to increase fuel flow to the engine and will therefore result in a maintaining NF ±1%
What is the expected droop during single engine operation?
As much as 3% RPM
If the droop compensator binds, what is the safety mechanism to prevent inability to control the engine?
A rivet in the collective linkage is designed to shear
What is the caution associated with a sheared droop compensator rivet?
NF governors will still control NFR PM but transient droop overspeed and recovery time for the engines will increase, collective adjustments should be made slow to prevent rotor decay or overspeed
How does the torque control unit work?
If an over torque condition is imminent, pneumatic signals are sent to both automatic fuel control units to reduce fuel flow to each engine resulting in reduced torque.
What is the torque control unit’s limiter setting?
102 to 104% torque
How does the torque control unit work?
It sums the torque pressures and compares them against a spring reference internally
How are the fuel sense line heaters powered?
Through the DC central bus, heaters are automatic and no cockpit indications are provided
How many fuel nozzles are used during the starting sequence?
7
What is the governing range for the power section of the turbine?
97 to 100% NF
How is the idle stop release switch powered?
28 Volt DC essential bus
How does the idle stop release switch work?
A solenoid and a plunger for each throttle acts as a stop, activation of the switch removes the stop from the system allowing the throttle to be brought above or below the idle range
The governor switch acts on which valves?
The fuel control solenoid valves which bypass the automatic fuel control governors
The instructor control panel allows for what?
Allows for override of the pilots start switch
What is the caution associated with the pilot override switch?
With the switch in the off position it is possible to engage both starters simultaneously, this should not be attempted due to extreme voltage drain which may result in the destruction of the aircraft battery
What are the four components of the engine ignition system?
An ignition exciter unit, two igniter plugs, starter generator, and start switch
What switch must be on for engine start to be completed?
The ignition key lock switch must be in the on position
Which clock positions are the igniter plugs located at within the combustion chamber?
4:00 and 11:00 positions
Which lighting system is disabled when this start switch is engaged?
The anti collision lights
The torque meter is energized by which electrical system?
26 Volt AC bus
What are the three cautions associated with the torque meter?
A single filled torque signal converter will cause the respective torque press circuit breaker to pop and cause a freeze of the torque indication providing inaccurate real time reading. If both torque signal converters fail it will cause both torque press circuit breakers to pop and all torque indications to freeze. If the 26 volt transformer fails, indications will resemble a dual torque signal converter failure but the circuit breakers will not pop
How are the inter turbine temperature gauges powered?
Through the 115 Volt essential bus
What is the purpose of the ITT bias box?
They provide for adjustment of ITT indications based on signals from the engine when compared against a standard for operating conditions
How is the triple torquemeter powered?
By three tachometer generators mounted on engines #1, 2, and the transmission. These systems are self generating and therefore electrical power is not required
How is the gas producer tachometer powered?
Powered by the accessory gearbox for each engine respectively, no electrical power required
How is engine oil temperature measured?
An electrical resistance type bulb located in the lower part of the accessory gearbox
How is the engine oil pressure measured?
Engine oil pressure transmitter located on the lower part of the accessory gearbox adjacent to the oil temperature bulb
How is the oil temperature bulb powered?
28 Volt essential bus
What will happen to the torquemeters if the 26 VAC transformer fails?
Dual Torque Signal Failure, Circuit Breakers will not pop
How are the inter turbine temperature gauges powered?
Through the 115 Volt essential bus
What is the purpose of the IT bias box?
They provide for adjustment of IT indications based on signals from the engine when compared against a standard for operating conditions
How is the triple torquemeter powered?
By three tachometer generators mounted on engines #1, 2, and the transmission. These systems are self generating and therefore electrical power is not required
How is the gas producer tachometer powered?
Powered by the accessory gearbox for each engine respectively, no electrical power required.
How is engine oil temperature measured?
An electrical resistance type bulb located in the lower part of the accessory gearbox
What is an alternate route for the oil pressure transmitter to be powered?
26 Volt AC electrical power from the ITT inverter when the battery switches in the start position or when the battery is in the on position and a start switch is actuated
The engine low oil pressure caution light is illuminated at what PSI?
30 PSI
How is power supplied to the engine fuel flow indicator?
Through the 115 Volt AC central bus
How many engine oil supply systems does this aircraft have?
3, one for each engine, and a third for the combining gearbox
Where is the oil filler for each engine?
On the accessory gearbox
Where is the oil cooler blower for the oil systems located?
On the combining gearbox
Where are the two chip detectors located for each engine?
A forward chip detector located on the accessory gearbox oil sump and an aft ship detector located on the combining gearbox
How are the engine chip detectors powered?
28 Volt DC essential bus
The oil debris detection system is located where?
Engine, combining gearbox, main transmission, 42, and 90 gear box systems
The oil debris detection system in the engines and CBG will remove particles through an electrical burn-off feature less than how large?
.003 inches
The oil debris detection system will burn off particles smaller than what size in the main transmission, 42, and 90° gearbox?
.005 inches
Particles larger than the system can burn off or result in what?
Illumination of the master caution ship detector lights
Are there different indications for chips in the engine versus chips in the transmissions?
Yes, two different master cautions for each
How is the oil debris detection system powered?
28 Volt DC essential bus
Where is the location of the oil coolers for the engine, combining gearbox, and transmission?
Aft of the combining gearbox
How is air supplied to the oil cooler?
Through a gear driven blower connected to the combining gearbox
How many blowers are required to maintain oil cooling?
Only one blower of the two is required which allows for appropriate cooling during single engine operations
Where is the engine oil tank located?
The accessory gearbox rear face
The engine oil tank has a capacity of how many quarts?
6.4 Quarts
The main transmission is limited to how much horsepower?
1290 shaft horsepower
Besides the main rotor what else is driven by the main transmission?
Hydraulic pumps, rotor brake disc, tachometer generator, and tail rotor drive shaft
What type of sump does the transmission oil system have?
A wet sump located at the bottom of the transmission
What is the capacity of the transmission oil system?
11 quarts
How many oil filters are located in the main transmission?
Two, an internal oil filter and an external oil filter
Which oil filter within the transmission has a bypass feature?
The external oil filter
At what PSI is the oil filter bypassed?
20PSI to begin with and fully bypassed by 80 PSI
At what temperature does oil start to flow through the transmission oil cooler?
54 C
At what oil temperature does all transmission oil flow through the oil cooler?
79 C
Transmission oil indicators are powered from what?
The oil temperature is supplied by 28 Volt DC essential bus and the pressure portion is powered by the 26 Volt AC bus
When does the transmission oil pressure caution light illuminate?
A drop in oil pressure below approximately 30 PSI
What circuit powers the transmission oil pressure caution light?
28VDC Essential Bus
At what temperature does the transmission oil pressure hot light illuminate?
110 C
How many stages of reduction gears are found in the combining gearbox?
3 stages
The first stage of the combining gearbox is lubricated by which system?
The respective engine oil system
The second stage of the combining gearbox drives which systems?
The NF tachometer generators, NF governors, and oil cooler blowers
The second stage combining gearbox gears are lubricated by which system?
The respective engine’s oil system
Where is the sprag clutch located?
On the third stage of the combining gearbox
Where is the torque control unit located?
The third stage of the combining gearbox
The third stage of the combining gearbox is lubricated by what?
The combining gearbox oil system
The sprag clutch allows for what?
One engine to continue to drive the transmission when the other engine speed is reduced for example in the setting of engine failure
