Powerplant

Question 1

What type of engines do we have?

Answer 1

Pratt and Whitney JT8D-219, dual spool, axial flow turbo fan

Question 2

How much thrust does each engine produce?

Answer 2

Max= 21,700

Normal= 21,000

Question 3

During the start sequence, what does moving the fuel control lever to ON do?

Answer 3

Completes the ignition circuit to energize the respective igniter

Question 4

On the rotary style ignition switch, what are the different positions and what are their functions?

Answer 4

OFF= both engine igniters are de-energized

A or B= directs the selected ignition system to the fuel levers

Both= both A and B igniters are energized when the fuel lever is ON

OVRD= both A and B igniters are energized regardless of fuel lever position

(All are high energy output-20 joules)

Question 5

What do the engine start switches do?

Answer 5

Control the start valves which controls the pneumatic supply to the starter

Question 6

What is the min N2 value during start? Normal?

Answer 6

Min= 20%

Normal= 22%-24%

Question 7

When is the start switch released?

Answer 7

38% N2

Question 8

Indications for stabilized start?

Answer 8

N1= 26%
EGT= 380*
N2= 54%
Fuel Flow= 980 pph
Hyd Press= 3000 psi

Question 9

How long does the fuel heat activate when placed ON? What does it use?

Answer 9

1 minute

13th stage bleed air

Question 10

When will the NO MODE light illuminate on the TRP?

Answer 10

• If an uncertified bleed air configuration is selected

- When no thrust mode is selected

Question 11

When will the ART READY light illuminate?

Answer 11

• ART switch in auto
• Aircraft on ground
• Both engines have valid N1
• Slats in takeoff range

Question 12

When is ART armed?

Answer 12

When both N1 are 65% or greater

READY light will flash

Question 13

When will ART activate?

Answer 13

• 30% N1 differential sensed
• N1 indicatior fails/invalid N1 input
• DFGC switched/fails
• Wind shear detected

Question 14

What is ART? What does it do?

Answer 14

Automatic Reserve Thrust

Increases power on operating engine by approx 700 lbs of thrust

Question 15

When is ART deactivated?

Answer 15

-Retraction of the slats
or
-Both engines drop below 49% N1
(will resume once back above 64% N1)

Question 16

What is the ATR? What does it do?

Answer 16

Automatic Thrust Restoration

Increases thrust to GA EPR in certain conditions, if engine fails during takeoff

Auto Throttles must be engaged for ART to work

Question 17

When is ATR armed?

Answer 17

• FD Pitch in T/O mode
• Above 350 ft RA
• Both engine EPRs are below GA EPR limits

Question 18

When will ATR activate?

Answer 18

-Greater than 0.25 EPR
and
-Greater than 7% difference N1
or
-Vertical speed less than 0 for 5 seconds (on T/O)

Question 19

What is a HOT start?

Answer 19

• Rapid rise in EGT to max limit

- Excessive fuel flow (1000 pph)

Question 20

What is a HUNG start?

Answer 20

N2 fails to reach normal operating speed (56%)

Question 21

What is a Slow acceleration?

Answer 21

Failure to reach min N2 to introduce fuel (20%)

Question 22

When would we use BOTH for the ignition?

Answer 22

-Temp is less than 6* C
or
-Second start attempt

Question 23

What are the different positions and functions on the toggle style ignition switch

Answer 23

Gnd Start and Continuous= high energy (20 joules) until start switch is release at 38% N2

-After start switch is released it reverts to Continuous mode, low energy (4 joules)

OVRD= Both igniters operate at high energy output (20 joules) regardless of fuel control lever position

Question 24

When will the fuel heat automatically activate?

Answer 24

In Auto:
-fuel filter accumulates ice

FUEL FILTER PRESS DROP
and
FUEL HEAT ON annunciators illuminate