POWER PLANT Flashcards
Oil is bypassed FCOC if?
- Above 93°C fuel temp
* Above 50 psid press (psi differential between Inlet and Outlet)
FADEC scheduling flight idle anti-ice OFF to: (5)
- Avoid flame out
- Over temp
- Inability to accelerate
- Provide bleed air
- Accelerate to full thrust in 8 sec.
What is CVG?
Where?
Compressor variable geometry
1-5 stages of HP compressor
and inlet guide vanes
- Engine efficiency
- Prevents from a compressor stall
ITT is measured by:
Thermocouple
Inside the 1st stage LP
Turbine stator vane
What connects N2 shaft with AGB?
Tower shaft
if brakes, engine fails
What’s attached to AGB (accessory gear box)? (6)
- 2 DC Generators
- 1 FPMU (Fuel Pump Metering Unit)
- 1 Oil Pump
- 1 Hydraulic Pump
- 1 PMA (Permanent Magnet Alt.)
- 1 Air Turbine Starter
ATTCS select T/O–1 if: (triggering) (7)
- Engine fails
- Below 15,000’ Gear DN and Locked
- Thrust lever above 78°
- Pushing T/O rating button (WOW and TLA below 50°)
- 1 TLA below 38°
- One Engine ATTCS not armed within 2 sec
- After arming TLA reduces below 42°
Abort the start IF: (8)
Fuel flow (F.F.) >800 lbs/hr before light-up../..
No light-up 10 sec. after F.F…/..
ITT at 6:30 on start ../..
N2 remains steady or decreases for >30 sec…/..
Unusual noise or vibration../..
Engine instruments indicate abnormal cond…/..
Fire visible on exhaust../..
Oil press below 34psi after start ../..
The oil pump assembly has…? Pumps
6
5-scavenge pumps
1-lubrication (pressure) pump
14th Stage Bleed open: (3)
Low thrust…..
Anti-icing is required…..
Cross bleed starting…..
FADEC will…? When N2 falls below 53% rpm
FADEC will terminate auto relight
FADEC will command both igniters when detects flame out
Purpose of FPMU (5)
FPMU- is an electrical mechanical unit. Operations directed by FADEC to control fuel for: 1. Starting 2. Operation 3. Wind milling 4. Shut down 5. CVG Operation
PMA (Permanent Magnet Alternator)
PMA is supplying
1. Igniters (avbl at 10% N2)
2. FADEC (at 50% N2)
3. Thrust Levers
Thrust Rating Buttons
(Only when primary power fails)The engine fuel system components: (4)
- Fuel Pump Metering Unit (FPMU)
- Fuel Cooled Oil Cooler (FCOC)
- Compressor Variable Geometry (CVG)
- Fuel Nozzles (16)
N1 Fan
How many blades?
24 blades
After aborted start
Dry motoring for 30 sec
Go by QRH
Engine lubrication system components (5)
- Oil tank
- FCOC
- Lube and scavenge pump
- Oil filter
- Air cooled oil cooler
Thrust Lever (detent) is…?
78% position
Thrust Reversers
- Operations
- Max Revers
- Uncommanded Revers
• Operation
Hydraulically operated
- Aircraft on ground, main wheels speed > 25kts
or Aircraft all wheels on ground
•Max Revers
- FADEC agree both engines deployed
- inop engine idle
•Uncommanded
- FADEC will command IDLE
X- Bleed Start (4)
X-Bleed — Open
Starting Eng — Bleed Close
Operating Eng — Bleed Open
Operating Eng — 80% N2
FADEC is scheduling idle thrust
(Flight idle anti-ice ON) inhabitation
This automatic rescheduling of idle is inhibited below 15,000 ft Gear DN and Locked
Fuel flow metering (on EICAS)
From 130 PPH to 4300 PPH
Min Oil Quantity
Min 6 qts.
- Advise mx at 8
- Return to hub at 6
- Don’t leave hub at 6
FADEC will shut down the engine if (N1, N2)
N1 exceed 100%
N2 exceed 102.5%
N2 falls below 54% RPM
Don’t read oil capacity for…? min after engine shutdown
30 min.
Purpose of CVG
- Make engine run more efficient
2. Helps to prevent from compressor stall
What is FADEC
Full Authority Digital Electronic Control
Thrust Reversers Lock Protection
3 Locks
1 and 2 - electro/hydraulic
3 - electro/mechanical
What is the Pressure Regulating Valve responsible for?
Supply the bearing with oil by equalizing the pressures between scavenge line center sump and pressure oil line when bearing seals are cold and let the high pressure air in (that might prevent lubrication of the bearing)
Lubrication Pump
Self-regulating pump with feed back from pressure regulating valve
Why does is show 14 qts on PFD?
Because of the angle of the oil tank
AE3007A1 Thrust
7426 lbs of thrust at ISA+30°C
Oil tank capacity
MAX- 12qts
At 5qts- warning (low level)
FPMU Pumps:
- Centrifugal pump (LP) raises fuel pressure
* Gear pump (HP) atomize fuel (mist)
Areas of lubrication
- Fan sump
- Fwd sump
- Center sump
- Aft sump
- AGB
FADEC Discrete outputs
1) N2 speed switch:
• Active: above 56.4%
• Inactive: below 53%
2) ECS off signal (T/O 1 Mode) only on engine bleeds
FPMU gear pump
provide how many PSI?
- 1000 psi for CVG
* 200 psi for fuel nozzles
Engine Start (6)
- Engine Rotation — N2
- Lubrication ——– Oil Press
- Ignition ———— N2 14% (ENG)
- Fuel Flow ——— N2 28% (PPH)
- Combustion —— ITT temp
- Stabilization ——
- ——N1 (2) ITT (4) N2 (6) FF 300 pph
What is the bypass ratio?
5 to 1
What valve reduces compression for easier start?
Compressor acceleration bleed valve at the 9th stage
What “ATTCS” stands for?
Automated Takeoff Thrust Control System
FADEC’s share what info between engines?
ATTCS, Thrust reversers
