Systems - Engine Flashcards
Engine type?
J85-GE-5.
8 stage, axial flow, turbojet engines
Thrust?
2,200 lbs MIL, 3,300 lbs MAX
Avoid Idle to MAX in <1 second
Engine components
Front frame Compressor Main frame Combustion section (25% fuel used) Turbine Section Exhaust section Afterburner section
What does the 8th stage compressor air operate?
Inlet Guide Vanes, Bleed Air Vanes
Defog, Canopy Seals, G Suits, A/C, Presurization, Hydraulic Pressure, Anti-Ice
Oil pump info
4 quarts (expansion space 1 quart) 1 pint/hr max consumption
Main fuel control functions
Stops flameouts/compressor stalls
Engine speed vs throttle position
Variable geometry system scheduling
Reduces fuel flow at low power settings
Main fuel control senses
Discharge pressure
Inlet temp
RPM
Throttle position
Afterburner fuel control functions
Supplies fuel to the spraybars
Schedules exhaust nozzle opening per T5 system
Afterburner fuel contorl senses
Discharge pressure
Throttle position
Nozzle actuator
Temp
What does T2 sensor do?
Limits fuel flow as a function of inlet temp
VHowe does variable area exhaust nozzle work?
- Maintains max thrust efficiency while controlling EGT
- May take 10 second sto assume position during rapid movement
- IDLE to 97% controls nozzle
- When retarded from MAX through 97%, nozzle closes
When does the nozzle open to ensure EGT limitations with the T5?
Beyond 97%
Anti-ice stats
- 8th stage compressor air
- B/w 94-98% RPM, EGT can rise 15 C
- Requires A/C power
- Requires 80% RPM (turns on at 65%)
- 9% thrust lost at MIL, 6.5% lost in MAX
- Should be used below 32 F and high humidity
Abort start if engine start does not occur by
30 seconds
Engine start: Throttle out of idle does what?
Energizes the ignition exciter and starts fuel flow
Engine start: Throttle to max does what without start button?
Energizes main and afterburner igniters for 30 seconds
- Going below MIL resets timer
Airstart range
12% required
18-20% heart of envelope
Which systems latch red?
RPM
EGT
G meter
Oil
If batt voltage less than ___, max brightness
22 VDC
What to do if no RPM rise after starting air applied?
Check CASS and tachometer
What to do if RPM doens’t rise to 12%
Check CASS
What to do if RPM doens’t reach 43% to 48% in 30 sec or drops below 46% after start?
Hold start button
Allow engine to warm up
What to do if FF exceeds 360 pph?
Cut off throttle, monitor engine for 2 mins, attmept next start
What to do if no EGT rise w/in 12 sec
Abort start, 2 minutes of CASS, restart
What to do if EGT exceeds 845
Attempt another start if 925 not exceeded
What to do if compressor stall?
- Pop or bang followed by vibration, RPM drop, and high EGT
- Retard throttle to IDLE, press start button, adjust airspeed
What to do if flameout?
Same as compressor stall, but RPM and EGT will decrease
What to do with stall/fmaeout susceptibility area?
- Restrict throttle movement not to exceed 1 in / 3 sec
- Increase airspeed as much as possible prior to afterburner
- > 28k feet below and below 0.6 IMN increases risk
- <30k ft and above 0.6 IMN not recommended
