Systems - Engine

Question 1

Engine type?

Answer 1

J85-GE-5.

8 stage, axial flow, turbojet engines

Question 2

Thrust?

Answer 2

2,200 lbs MIL, 3,300 lbs MAX

Avoid Idle to MAX in <1 second

Question 3

Engine components

Answer 3

Front frame
Compressor
Main frame
Combustion section (25% fuel used)
Turbine Section
Exhaust section
Afterburner section

Question 4

What does the 8th stage compressor air operate?

Answer 4

Inlet Guide Vanes, Bleed Air Vanes

Defog, Canopy Seals, G Suits, A/C, Presurization, Hydraulic Pressure, Anti-Ice

Question 5

Oil pump info

Answer 5

4 quarts (expansion space 1 quart)
1 pint/hr max consumption

Question 6

Main fuel control functions

Answer 6

Stops flameouts/compressor stalls
Engine speed vs throttle position
Variable geometry system scheduling
Reduces fuel flow at low power settings

Question 7

Main fuel control senses

Answer 7

Discharge pressure
Inlet temp
RPM
Throttle position

Question 8

Afterburner fuel control functions

Answer 8

Supplies fuel to the spraybars

Schedules exhaust nozzle opening per T5 system

Question 9

Afterburner fuel contorl senses

Answer 9

Discharge pressure
Throttle position
Nozzle actuator
Temp

Question 10

What does T2 sensor do?

Answer 10

Limits fuel flow as a function of inlet temp

Question 11

VHowe does variable area exhaust nozzle work?

Answer 11

• 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

Question 12

When does the nozzle open to ensure EGT limitations with the T5?

Answer 12

Beyond 97%

Question 13

Anti-ice stats

Answer 13

• 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

Question 14

Abort start if engine start does not occur by

Answer 14

30 seconds

Question 15

Engine start: Throttle out of idle does what?

Answer 15

Energizes the ignition exciter and starts fuel flow

Question 16

Engine start: Throttle to max does what without start button?

Answer 16

Energizes main and afterburner igniters for 30 seconds

- Going below MIL resets timer

Question 17

Airstart range

Answer 17

12% required

18-20% heart of envelope

Question 18

Which systems latch red?

Answer 18

RPM
EGT
G meter
Oil

Question 19

If batt voltage less than ___, max brightness

Answer 19

22 VDC

Question 20

What to do if no RPM rise after starting air applied?

Answer 20

Check CASS and tachometer

Question 21

What to do if RPM doens’t rise to 12%

Answer 21

Check CASS

Question 22

What to do if RPM doens’t reach 43% to 48% in 30 sec or drops below 46% after start?

Answer 22

Hold start button

Allow engine to warm up

Question 23

What to do if FF exceeds 360 pph?

Answer 23

Cut off throttle, monitor engine for 2 mins, attmept next start

Question 24

What to do if no EGT rise w/in 12 sec

Answer 24

Abort start, 2 minutes of CASS, restart

Question 25

What to do if EGT exceeds 845

Answer 25

Attempt another start if 925 not exceeded

Question 26

What to do if compressor stall?

Answer 26

• Pop or bang followed by vibration, RPM drop, and high EGT

- Retard throttle to IDLE, press start button, adjust airspeed

Question 27

What to do if flameout?

Answer 27

Same as compressor stall, but RPM and EGT will decrease

Question 28

What to do with stall/fmaeout susceptibility area?

Answer 28

• 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