Engines Flashcards
Type of engine? 737-700
CFM56-7
What are the five sections of the engine?
Fan section
Compressor section
Combustion section
Turbine section
Exhaust
Pneumatic airbus taken from the ____ and ____ we of the _____ pressure compressor
5th and 9th stages of the high pressure compressor
The accessory drive is located on the ____ side of the engine and includes what items?
Left side
Oil scavenge pump
Engine fuel pumps
IDG
Starter
Hydraulic pump
What is the EEC?
Electronic engine control
Aka FADEC
There are ___ EECs per engine, with each EEC having __ modes.
One per engine
Two modes per EEC
The EEC interfaces with what engine components?
Hydro mechanical unit to meter correct amount of fuel into the engines
Engine air control systems to change variable stator vane angles and bleed air valves
Fuel flow transmitters
Ignition and starting system
Thrust reversers
The EEC has how many control modes? What are they?
Two
Normal and alternate (soft/hard)
How do you know if the aircraft is in soft vs hard alternate EEC modes?
If the ON and ALTN are both illuminated, you’re in soft alternate.
If only the ALTN mode is illuminated, you’re in hard alternate
How do you switch from soft to hard alternate mode?
Retard thrust lever to idle or push the respective EEC button
How does the soft alternate EEC mode determine engine parameters?
Uses the last valid flight conditions
T/F: If an engine reverts to the alternate mode, non-normal procedures will direct BOTH engines to operate in the alternate mode for the duration of the flight
True
What does the hard alternate mode do?
Always provides equal to or greater thrust than the normal mode for same lever position
What does the illuminated ENGINE CONTROL light mean?
These lights only operate on the ground and indicate that the aircraft is not to takeoff due to engine control system malfunctions
Active below 80 kts prior to takeoff and approximately 30 seconds after touchdown
What are the three “idle settings” and when are they active?
Ground idle. Active for ground operations
Flight idle: Active in flight when approach idle isn’t active
Approach idle: Active in flight with flaps in landing configuration or either engine anti ice is selected on. N1/N2 will be higher than flight idle to reduce acceleration time in the event of a go around.
If there is a fault that prevents the EEC from receiving flap or anti-ice signals when does the EEC command approach idle?
Below 15,000 ft MSL
How will engine indicating display an engine parameter exceedance?
N2, oil temperature, and oil pressure will turn amber or red
A box appears around the digital display on the ground after engine shutdown following an inflight exceedance
On the engine indications REV in amber means what?
Green?
Respective thrust reverser is moved from stowed position
Respective thrust reverser is deployed
What does a white blinking EGT indicate?
The EEC senses conditions that may lead to hot start or stall during ground starts.
The EEC will automatically cut off fuel for an impending hit start or stall during ground starts
What does the START VALVE OPEN light indicate?
Steady: Respective engine start valve is open and air is supplied to the starter
Blinking: Uncommanded opening of start valve
What does OIL FILTER BYPASS indicate on the crew alert?
Blinking/Steady: Indicates an impending bypass of the scavenge oil filter
What does LOW OIL PRESSURE mean on the crew alert system?
Blinking/Steady: Oil pressure at or below red line
Blinking of crew alerts on the crew alert system is inhibited when?
During takeoff from 80 kts to 400 ft RA, or 30 seconds after reaching 80 kts, whichever occurs first
During landing below 200 ft RA until 30 seconds after touchdown
What does XB indicate next to the N2 indication?
Crossbleed start is required. No windmill starts
If starting an engine from battery power only, which igniter must be selected and why?
Right igniter
It is powered by the AC STBY BUS
Where does the left igniter receive power from?
AC TXFR BUS
When will the EEC command the igniters on?
Even if the engine start switches are selected OFF, the EEC turns on the ignition system if the EEC senses a possible engine flameout
Engine ignition must be on under what conditions?
Takeoff
Landing
Operation in heavy rain
Anti-ice operation
Severe turbulence
When should you set the engine start lever to IDLE?
25% N2
or
Max Motoring, defined as N2 acceleration less than 1% rise in approximately 5 seconds
What is the MINIMUM N2 indication to set the start lever to IDLE?
20%
When does the start switch go from GRD to OFF automatically?
Starter cutout speed (approximately 56% N2)
What conditions dictate aborting an engine start?
N1 or N2 does not increase, or increases very slowly after the EGT increases
No oil pressure indication by the time the engine is stabilized at IDLE
EGT does not increase by 10 seconds after the start lever is moved to IDLE
EGT quickly nears or exceeds start limit
What happens if the engine detects an engine flameout?
Both igniters are commanded on
How does the EEC handle a wet start?
If a wet start is detected, the EEC turns off ignition and shuts off fuel to the engine 15 seconds after the start lever is moved to IDLE
How long is engine warm up before setting takeoff power?
2 mins
What is the engine cool down time?
Run engines for at least 3 mins before shutdown (recommended)
Run engines for at least 1 minute before shutdown (requirement)
Which hydraulic systems pressurize the reverse thrusters?
Engine 1 - Hydraulic System A
Engine 2 - Hydraulic System B
If either system A or B fails, standby hydraulics pressurize the thrust reversers but at a slower rate
When does the REVERSER light on the overhead panel illuminate?
The thrust reverser is commanded to stow, the light extinguishes 10 seconds later when the isolation valve closes
How does the aircraft indicate a malfunction with the thrust reverse system?
The REVERSER light on the overhead panel illuminates for >12 seconds, MASTER CAUTION, and ENG system annunciator lights illuminate
