M15.7 Exhaust And Thrust Reverser

Question 1

What does the exhaust cone do

Answer 1

Prevents reverse flow into the hub

Question 2

Common exhaust nozzle advantage

Answer 2

Reduces the very high exhaust gas velocities

Question 3

Disadvantage of common exhaust nozzle

Answer 3

Increased weight

Question 4

Convergent exhaust nozzle max pressure ratio

Answer 4

2:1

Question 5

What type of exhaust is used on aircraft that fly faster than the speed of sound

Answer 5

C-D exhaust convergent-Divergent

Question 6

Unit used to express noise

Answer 6

Effective perceived noise decibel (EPNdB)

Question 7

What does EPNdB take into account

Answer 7

• Pitch
• Duration
• Pressure

Question 8

EPNdB

Answer 8

Effective Perceived Noise deciBel

Question 9

Smaller eddies can cause noise in what frequency

Answer 9

Very high

Question 10

At what bypass ratio is the jet noise so low the internal noise becomes available

Answer 10

5:1

Question 11

Thrust reverse deflection angle

Answer 11

45 to 60 degrees

Question 12

Types of thrust reversers

Answer 12

• Clam shell
• Bucket
• Fan Reverser (Translating sleeve)
• Pivoting door

Question 13

When are reversers most effective

Answer 13

Shortly after landing (high speeds)

Question 14

Adverse effects of thrust reverser

Answer 14

• FOD
• Decreased braking
• High EGT
• Stall danger

Question 15

Thrust reverse main subsystems

Answer 15

• Control
• Actuation
• Airflow Deflection

Question 16

What protects the reverse thrust control system

Answer 16

Air Ground Logic

Question 17

Advantage of using the radio altimeter for reverse control

Answer 17

On short runways the thrust reverse can be deployed less than 10ft

Question 18

Thrust reverser interlock purpose

Answer 18

Engine power can only be increased once the reverser is fully deployed

Question 19

What ensures reverse door stowage

Answer 19

• Reverse door latch
• Internal actuator locks

Question 20

Thrust reverse indications

Answer 20

Amber - Reverse unlock

Green - Fully deployed

Question 21

What can actuate thrust reversers

Answer 21

Hydraulic or pneumatically

Question 22

What slows the translating cowl when close to fully deployed

Answer 22

Feedback mechanism

Question 23

Reverser deactivation methods

Answer 23

• Pneumatically
• Electric
• Mechanical

Question 24

Which mechanical thrust reverser deactivation visually shows lockout condition

Answer 24

Red signal plates

Question 25

Advantage and disadvantage of hydraulic actuators with internal latch mechanisms

Answer 25

Adv - No need for control

Diss - Expensive
Diss - Complicated

Question 26

Advantage and disadvantage of reverser door latch

Answer 26

Adv - Simple

Diss - Sequence control required

Question 27

How is reverse actuator synchronisation in translating sleeves achieved

Answer 27

Interconnecting flexible drive shafts