Engine & Power Systems Flashcards
MAX Thrust/MAX Rated Thrust
20,700 lbs / 21,890 lbs
FAN VIB Max
1.6 ips
CORE VIB Max
2.2 ips
FADEC
Full Authority Digital Engine Control
Controls engine parameters based on Mission Computers (MC), Flight Control Computers (FCC), and Throttle angle by modulating fuel flow and engine geometry
2 FADEC’s:
- 1 per engine
- Each FADEC has two channels
ENGINE STATUS
NORM - Engine performance is normal
PERF 90 - 10% or less thrust loss and or slower engine transients. Afterburner is not inhibited
AB FAIL - No Afterburner capability
THRUST - Engine thrust is limited to between 40% and 90% and significantly slower transients
IDLE - Engine is limited to idle power only
SHUTDOWN - Engine automatically shut down
Oil Systems
1 Engine oil system
1 AMAD oil system
Both systems contain a pump, scavenge filters, chip detectors, routed through the AMAD and hyd oil fuel heat exchanger
OIL PRESSURE
Pressure transducer senses exact oil pressure
Pressure switch senses above 35psi
If EFD shows 0 psi but no OIL PR Caution, the transducer has failed
OIL TEMPERATURE
If Engine Oil > 149C or AMAD Oil > 88C, OIL HOT Caution will appear.
Must check engine page to identify problem source.
Best cooling RPM is 72% N2
FADEC Power Sources
Normal Power is provided by Engine Driven Alternator with 28 VDC Essential bus serving as a backup.
10 seconds after both generators are online the backup power is tested. If insufficient, this will provide a FADEC DEGD and takeoff is prohibited.
FADEC will operate opposite channel from the previous flight.
FADEC Alternator Fail (CH A / CH B)
CH A powered by - ESS DC Bus, GEN through transformer rectifier, PMG, Battery
CH B powered by - Engine DC Bus, opposite Engine DC Bus
Engine Driven Alternator
Via a separate dedicated shaft, provides electrical power to:
- FADEC
- Ignition Systems
- Afterburner
Ignition System
FADEC controlled providing alternator power to ignition exciters.
- 10-45% rpm during start
- Flameout
- Throttle in AB until AB lit
- Trigger squeeze +5sec for Gun, any A/A weapon, or forward firing A/G weapon
VEN (Variable Exhaust Nozzle)
Controlled electrically by FADEC
Fuel used as hydraulics to position Nozzle
Provides maximum thrust efficiency during Idle (opens 77-83% to maximize airflow)
Less than MIL (Closed 0-45%) to maximize subsonic airflow
Afterburner (Full Open 50-100%) to maximize supersonic airflow
Engine Anti-Ice
Operational when Inlet Ice detector senses 0.025” of ice while airborne and inlet temp is -40C to 15C
System shuts off with WonW
Uses 7th stage bleed air
- Increases N2 by 2% and EGT by 5C
Executes Self Test 45sec after engines idle, stays on for 30sec
- will see L/R HEAT advisory on DDI
Fan Speed Lockup (SLU)
Hold engine RPM at MIL when throttles reduced at high speed until aircraft slowed to prevent inlet instability and reduce buzz.
Active >1.23IMN until below 1.18IMN
