Engines Flashcards
Engine Nomenclature
Roll Royce Trent 892
Engine Description
- Three rotor
- Axial flow turbofans
- High compression
- High bypass ratio
Describe the N1 rotor
- Low pressure compressor section
- Low pressure turbine section
- On a common shaft
Describe the N2 rotor
- Intermediate pressure section
- Intermediate pressure turbine
- On a common shaft
Describe the N3 rotor
- High pressure compressor section
- High pressure turbine section
- On a common shaft
- Drives the engine accessory gearbox
What are the primary engine indications?
- EPR
- N1
- EGT
What are the secondary engine indications?
- N2
- N3
- Fuel flow
- Oil pressure, temperature, quantity
- Engine vibration
Describe EEC
- Dual channel
- Has full authority over its respective engine’s operation
- Uses thrust lever inputs to automatically control forward and reverse thrust
What are the two control modes of the EEC?
- NORM
- ALTN
How does the EEC set thrust in the NORM mode?
By controlling EPR based on thrust lever position
When does the EEC switch to soft alternate mode?
Automatically when required signals are not available to operate in the normal mode
How does the EEC set thrust in ALTN mode?
By scheduling N1 as a function of thrust lever position
What are the two alternate modes of the EEC?
- Soft
- Hard
What may happen when hard ALTN is selected?
Thrust may change to set the commanded N1
What protection is not provided in the ALTN modes?
Thrust protection
What protection is provided by the EEC in both NORM and ALTN modes?
N1, N2, N3 redline overspeed protection
What does the EEC command if N1, N2, N3 approaches overspeed?
Reduced fuel flow
What does the FUEL CONTROL and ENGINE FIRE switches control?
Fuel spar valve
What does the engine’s oil system provide?
High pressure oil for cooling and lubricating the main bearings, gears, and the accessory drive unit
Where is oil pressure measured?
Prior to entering the engine
Where is oil temperature measured?
After leaving the engine
What are the three bleed air sources for starting the engine?
- APU
- High pressure ground air
- The other engine, if it’s running
How long must the engines be warmed up before applying takeoff power if they have been shut down for up to 1.5 hours?
3 minutes
How long must the engines be warmed up before applying takeoff power if they have been shut down for over 1.5 hours?
5 minutes
What happens when the AUTOSTART switch is ON and FUEL CONTROL switch is in the RUN position?
- Spar valve opens
- Engine fuel valve arms
- The selected igniter arms
What is not monitored by the AUTOSTART system?
- Oil pressure
- Oil temperature
What malfunctions will the AUTOSTART system make a 2nd start attempt for?
- Hot start
- Hung Start
- No EGT rise
- Compressor stall
“ Hot, hung, no, bang”
On the ground, what malfunctions will the AUTOSTART system NOT make a 2nd start attempt for?
- Starter shaft fails
- Insufficient air pressure
- No N1 rotation
- Start time exceeds the starter duty cycle
- Start is aborted above starter cutout speed
“SANDE”
What does the EEC activate the auto relight function for?
- Engine flameout protection
- Rain and hail ingestion
When is the auto relight function activated?
- When an engine is at or below idle with the FUEL CONTROL SWITCH set to RUN
- When excessive rain or hail is ingested
When does the EEC disables the auto relight function?
- If engine does not recover and N3 drops below 35%
- Fuel and ignition are also shut off
What are the three EEC Idle Modes?
- Minimum
- Intermediate
- Approach
When is Minimum Idle Mode commanded by the EEC?
During ground operations
When is the Intermediate Idle mode commanded by the EEC?
When the landing gear is in the DN position
When is the Approach Idle Mode commanded by the EEC?
- When flaps are commanded to 25 or greater
- When engine anti-ice is in use
- When one hydraulic air-driven demand pump is inoperative with flaps out of the UP position
- When the opposite engine bleed air valve is closed
Note: Approach Idle decreases acceleration time in the event of a Go-Around
What happens when the thrust reverse levers are at the interlock position?
- Autothrottle disengages
- Auto speed brakes deploy if not previously armed
