Powerplant

Question 0

What does N1 shaft consist of?

Answer 0

Two-stage axial low compressor w/ fan and gas-path accelerator attached to two-stage low pressure turbine

Question 1

What type of engine is the JT15D-5 considered?

Answer 1

Twin-spool turbofan

Question 2

What does N-2 consist of?

Answer 2

Single-stage centrifugal stage compressor attached to a single-stage high pressure turbine

Question 3

What drives the accessory gearbox?

Answer 3

High-pressure compressor

Question 4

What items are located in the engine accessory gearbox?

Answer 4

• DC starter generator
• high press. fuel pump and HMU
• two N2 speed sensors
• Oil pumps
• hydraulic pumps

Question 5

How many oil pumps are driven by the accessories gearbox?

Answer 5

3 one pressure pump and two scavenge pumps

Question 6

What primarily controls fuel scheduling to the engine?

Answer 6

Hydro-mechanical unit (HMU)

Question 7

How many fuel pumps each engine?

Answer 7

1 (2 if stby pump in collector tank considered)

Question 8

What fuel pumps are installed on each engine?

Answer 8

HMU HP pump

Question 9

How many fuel pumps are on the Beechjet 400A?

Answer 9

4 … Two standby and Two HMU HP pumps

Question 10

What are two modes of the ignition system?

Answer 10

• Start ignition

- Continuous ignition

Question 11

When is start ignition available?

Answer 11

When switch is in STBY, ignition is activated when the start relay closes and terminates when the start relay opens at the end of a start cycle

Question 12

When is continuous ignition active?

Answer 12

• When ignition switch is ON
• engine anti-ice ON
• approaching stall

Question 13

What prevents fuel filter icing?

Answer 13

Fuel heater (operates automatically)

Question 14

What is heat source for fuel heater?

Answer 14

Engine oil

Question 15

Can the engine operate without the working main jet pump?

Answer 15

Yes, standby pressure is sufficient

Question 16

Can the engine operate without a HP pump from the HMU?

Answer 16

No

Question 17

What does HMU do?

Answer 17

• Fuel scheduling

- closes fuel shutoff valve on shutdown

Question 18

What functions does EFC provide?

Answer 18

• Engine starting
• steady-state operation
• acceleration/deceleration
• N2 governing

Question 19

What analog inputs does EFC unit receive?

Answer 19

• thrust level angle
• ambient air temp. (T0)
• ambient air pressure (P0)
• differential btwn air press and total air press.
• N1 and N2 speed sensors

Question 20

How does engine sync work?

Answer 20

Right EFC torque motor commands fuel to right engine to match left engine speed

Question 21

Where is EMER STOW function powered from?

Answer 21

Emergency BUS

Question 22

What happens if thrust reverser deploys uncommanded?

Answer 22

Thrust lever will snap to idle

Question 23

If oil pressure drops below 50psi on either engine, how much power can you use on that engine?

Answer 23

60% N2