Big Deck Energy

Question 1

What engine is installed on the LJ35 and what is the rated thrust?

Answer 1

TFE731-2-2B or 2C, 3,500 lbs of thrust at sea level up to 72o F

Question 2

Concerning the -2C DEEC fuel computers, what are the buffer (memory) limits?

Answer 2

40 cycles and the fuel computer light flashes at slow interval

50 cycles and the buffer overwrites the oldest cycles

Question 3

What are the engine starter limits?

Answer 3

1 minute
1 minute
15 minute (coffee break)
1 minute
1 minute
60 minutes (lunch break)

Question 4

What activates the ignitors during a normal engine ground start?

Answer 4

Moving the thrust levers from cutoff to idle

Question 5

What is the purpose of the soft start protection and explain its operation?

Answer 5

To prevent shearing the tower shaft. DC voltage is reduced to 12 VDC for 1.5 seconds when the start sequence is initiated

Question 6

When may engine sync not be used?

Answer 6

Takeoff, landing and single engine operation

Question 7

What is the maximum continuous cruise ITT?

Answer 7

2B:
795o C recommended,

832o C for 30 minutes recommended,

832o C Do not exceed maximum N1

-2C: 827o C recommended, 865o C for 30 minutes recommended, 865o C Do not exceed maximum N1

Question 8

What does a slow flashing Fuel Computer light represent on the -2C DEEC fuel computers?

Answer 8

The fuel computer buffer (memory) is full and needs to be downloaded

Question 9

What is the power source for the oil pressure gauge?

Answer 9

26 VAC

Question 10

What type of engine oil is utilized in the TFE731?

Answer 10

Mobil 254 Type II

Question 11

What is the normal oil temperature range?

Answer 11

Normal Range - 30-127C

Caution Range - 127-139C

Redline - 140C

Question 12

When should the oil level be checked?

Answer 12

Within one hour after shutdown, preferably 15 minutes up to one hour after shutdown

Question 13

If the fuel computer fails, what protection do you lose?

Answer 13

Ultimate overspeed protection (109% N1 or 110% N2) is lost You will still have the mechanical overspeed governor protection (105% N2)

Question 14

What engine systems are affected when a fuel computer fails?

8

Answer 14

Ultimate overspeed protection is lost

Over temperature protection is disabled

Engine response is slower

Single engine takeoff, climb and landing performance are degraded

Fuel consumption is affected

Surge bleed valve fails to 1/3 open

SPR is disabled

Engine sync

Question 15

What are the five major components of the TFE731-2 engine and how many bearings do they rest on?

Answer 15

Spinner and Fan (11,502 RPM)

Low pressure spool (N1) (20,688 RPM)

High pressure spool (N2)
-2B(29,692 RPM) -2C(30,100 RPM)

Annular combustion chamber

Transfer gearbox

Accessory gearbox

6 bearings

Question 16

How many duplex fuel atomizers supply fuel for the combustion chamber?

Answer 16

12

Question 17

How many thermocouples, which are located between the high pressure turbine (N2) and the low pressure turbine (N1), measure ITT?

Answer 17

10

Question 18

What are the approximate thrust percentages between the Core and the Fan?

Answer 18

At Sea Level: Fan = 60% Core = 40%

At FL 400: Fan = 40% Core = 60%

Question 19

Why are the engine core rotation clockwise and the fan rotation counterclockwise (as viewed from the aft)?

Answer 19

Smaller engine mounts are utilized because of the counteracted torque. If a part of the engine seizes, the torque is counteracted and will not shear the engine from its mounts.

Question 20

A solid-state, high-energy ignition system consists of a dual ignition exciter (induction vibrator) mounted on the engine and two igniter plugs in the combustion chamber. What are the locations of the ignitors on the engine as viewed from the aft?

Answer 20

6 and 7

Question 21

What is the approximate voltage output of the induction vibrator?

Answer 21

Input = 28 VDC

Output = (18,000 to 24,000) VDC

Question 22

When you perform the fire detection system test, what does the test check?

Answer 22

The continuity of the sensing elements and control units (DC powered through Left Essential Bus)

Question 23

What actions occur when the Fire T Handle is pulled?

Answer 23

Bleed air, hydraulic and fuel valves electrically close and the fire bottles are armed