17.2

Question 1

Propellers are categorised in 3 types of materials

Answer 1

Wooden
Composite
Metal (aluminium alloy or steel)

Question 2

Which wooden propeller is the most common

Answer 2

Birch

Question 3

How many layers of wood laid down when glued together form a blank

Answer 3

5

Question 4

Most wooden propellers are finished with

Answer 4

• natural wood finish
• grey or black plastic coating

Question 5

The blank is roughly shaped and allowed to rest for a week to allow for what

Answer 5

Equal distribution of moisture through all the layers (known as white)

Question 6

Why is the cotton fabric doped

Answer 6

Protect weather and UV deterioration

Question 7

How is the metal tipping secured to the blade

Answer 7

• By countersunk screws (at thick blade section)
• copper rivets (near the tip)

Question 8

Why are small holes drilled in each propeller tip

Answer 8

• allow to release moisture
• wood to breathe

Question 9

What is a alternate reinforcing method instead of doped cotton fabric before metal tipping is applied

Answer 9

Plastic (for added protection and strength)

Question 10

What is the final coating of polyurethane paint for

Answer 10

Mechanical and Uv ray protection

Question 11

How is the wooden propeller mounted to engine

Answer 11

• splined
• tapered
• forged steel hub
• bolted

Question 12

Are composite propellers stronger than metal

Answer 12

Yes

Question 13

What is the problem with composite propellers

Answer 13

Damage can be difficult to detect

Question 14

What shields are use to protect leading edge from impact damage

Answer 14

Nickel or stainless steel erosion shields

Question 15

What is used to limit lightning strike damage

Answer 15

Metal foil mesh

Question 16

The composite propellers spar absorbs what forces

Answer 16

Centrifugal forces and bending loads

Question 17

The composite propellers spar absorbs what forces

Answer 17

Centrifugal forces and bending loads

Question 18

Construction of composite blades without metal spar comprises of what

Answer 18

2 carbon fibre components

Question 19

The hollow centre construction in composite blades without metal spar is filled with what

Answer 19

Polyurethane foam

Question 20

Metal propellers are constructed from what

Answer 20

• Aluminium alloy
• steel

Question 21

Is aluminium alloy or wooden propeller more durable

Answer 21

Aluminium alloy

Question 22

How is the lead wool retained in its place in a composite blade without metal spar

Answer 22

By a rubber plug

Question 23

What is the most common blade surface finish

Answer 23

Anodising

Question 24

Steel propeller blades are typically hollow to keep weight to a minimum (T or F)

Answer 24

True

Question 25

How is the propeller blade angle measured from root to tip

Answer 25

Blade protractor

Question 26

The master station is also a reference point as to where most of the thrust of the blade is produced (T or F)

Answer 26

True

Question 27

When RPM increases what happens to AOA

Answer 27

Reduce AOA

Question 28

Controllable pitch propeller has 2 controls which are

Answer 28

- Throttle control - propeller control

Question 29

What is the most popular controllable pitch propeller system design used today

Answer 29

Beech-Roby

Question 30

How is the pitch change initiated in the cockpit

Answer 30

Crank handle which directly drives a pinion gear

Question 31

What is a constant speed propeller

Answer 31

automatically change blade pitch to allow it to maintain constant RPM

Question 32

What are the most common propeller drive shaft types

Answer 32

- Tapered - Splined - Flanged

Question 33

Where are tapered shafts usually found

Answer 33

- small, older, low powered piston engine

Question 34

If aircraft is in under speed mode what blade pitch is used

Answer 34

Fine pitch

Question 35

The propeller shaft of high output radial engines is generally splined (T or F)

Answer 35

True

Question 36

Where are flanged propeller shafts used

Answer 36

- modern reciprocating and turboprop engines

Question 37

What is the reason for spinner installation

Answer 37

- mechanical protection for hub - aesthetic reasons

Question 38

What is the propeller spinner usually manufactured from

Answer 38

- spun aluminium alloy - glass fibre composites

Question 39

Why do some flanges have index pins

Answer 39

Can be only installed in one position

Question 40

Dynamic load on the spinner is extremely high

Answer 40

True

Question 41

What should you ensure when installing spinner

Answer 41

- no noticeable wobble is identified

Question 42

How is constant speeding propeller accomplished

Answer 42

By using a constant speed unit or a governor

Question 43

What is the propeller spinner attached to

Answer 43

Spinner backplate (spinner bulkhead)

Question 44

How is a spinner repaired

Answer 44

Stop drilling