Systems

Question 1

What type of rotor system?

Answer 1

Starflex semi-rigid 3 bladed

Question 2

Describe the MGB Modules?

Answer 2

1: epicyclic reduction gear
2: bevel gear
3: lubrication gear

Question 3

Which engines are used?

Answer 3

B4: Arriel 2B1
T2: Arriel 2D

Question 4

How tall is the rotor system?

Answer 4

10.96’

Question 5

How long is the aircraft?

Answer 5

41.47’

Question 6

How wide is the aircraft?

Answer 6

7.57’

Question 7

What are the three datum references?

Answer 7

X is longitudinal
Y is lateral
Z is horizontal

Question 8

How do the skids try to prevent ground resonance?

Answer 8

Mustache shape and three point fitting with elastomer bearings

Question 9

How many suspension bars support the MGB?

Answer 9

4

Question 10

Why does the MGB need suspension?

Answer 10

Due to rigid attachment to rotor

Question 11

How is the MGB secured to the airframe?

Answer 11

4 rigid bars at the top of airframe

4 suspension bars at MGB

Question 12

How are the MGB vibrations absorbed?

Answer 12

Laminated pads which are flexible in shear and stiff in compression

Question 13

What’s the purpose of flex couplings?

Answer 13

To absorb small misalignments

Question 14

Where is the MGB low pres switch?

Answer 14

Left side of MGB Mod 2

Question 15

Where is the MGB chip switch?

Answer 15

1. Drain plug on MGB mod 1 next to sight glass

2. Top of MGB

Question 16

Where is the MGB temp switch?

Answer 16

Next to chip detector / sight glass / mod 1

Question 17

What is the max / rec / company rotor brake speeds?

Answer 17

170 / 140 / 100

Question 18

How is each blade identified?

Answer 18

Colored adhesive tape

Question 19

When does the main rotor system require servicing?

Answer 19

Never

Question 20

What is a starflex?

Answer 20

A rotor hub which is star shaped (3 arms) and flexible in flapping direction.

Question 21

What’s the “heart” of the starflex?

Answer 21

Spherical Thrust Bearings

Question 22

Describe a Spherical Thrust Bearing?

Answer 22

A bearing flexible in torsion, flapping and drag but rigid in compression.

Question 23

What’s the purpose of a frequency adaptor?

Answer 23

In-plane dragwise dampening and rigidity. Dampening to limit oscillations and stiffness to adjust the natural frequency.

Question 24

What absorbs the in-plane dragwise movements?

Answer 24

Frequency Adaptor

Question 25

Can you misassemble a starflex hub?

Answer 25

No, every part is either identical or foolproofed.

Question 26

Which trim tabs can be adjusted on the MR Blades?

Answer 26

Inner 2 tabs

Question 27

How is the MR RPM acquired?

Answer 27

A magnetic rate sensor (phonetic sensor) placed in front of a slotted wheel (ring gear)

Question 28

Which PCB processes the aural warning for RRPM?

Answer 28

PCB 1 in ASU

Question 29

What’s the ASU?

Answer 29

Then ancillary system unit ensures helicopters electrical ancillary functions.

Question 30

What functions are provided by the ASU?

Answer 30

Visual and Aural warnings, Nr signal for VEMD and EBCAU functions

Question 31

What’s an EBCAU?

Answer 31

Engine Backup Control Ancillary Unit. | Provides back up engine management

Question 32

What reduces cabin vibrations?

Answer 32

Cabin resonators

Question 33

What’s a cabin resonator?

Answer 33

A series of weights attached to the cabin to counteract main rotor vibrations

Question 34

How does the rotor hub vibration absorber work?

Answer 34

It uses a weight on a set of springs to counteract loads exerted on the rotor hub.

Question 35

How many shafts make up the tail rotor drive shaft?

Answer 35

3. Short, intermediate and rear shaft

Question 36

What’s the tail rotor short shaft made out of and why?

Answer 36

Steel, due to exhaust heat.

Question 37

How many couplings support the tail rotor shaft?

Answer 37

4 flex couplings

Question 38

How is the tail rotor lubricated?

Answer 38

Splash lubrication

Question 39

Which way should the tail rotor “mickey mouse ears” face?

Answer 39

Backwards / Aft

Question 40

How are pedal inputs transferred to the tail rotor?

Answer 40

Flex ball cable

Question 41

What degrees are the fenestron blades mounted?

Answer 41

45° / 32.5° / 25 °

Question 42

What’s the TR RPM

Answer 42

3568 RPMs

Question 43

What’s the purpose of the boss weights?

Answer 43

To generate a moment counteracting the blade zero pitch return moment so that the air foil is stabilized at a set pitch

Question 44

What’s unique about the swashplate?

Answer 44

Uniball / Teflon design

Question 45

Where is the starter/generator mounted?

Answer 45

Right side of engine on the bottom

Question 46

When does the starter become a generator?

Answer 46

When it produces more than 0.5V difference to the busbar.

Question 47

What type of servos are used?

Answer 47

Double rotary distributor design

Question 48

Where are the servos anchored?

Answer 48

To the bell housing of the MGB

Question 49

What’s the purpose of a double rotary distributor valve?

Answer 49

Prevents flight controls from being jammed if a valve seizes.

Question 50

How does the double distributor valve work?

Answer 50

It leverages a locking spring, which when freed actuates a microswitch for notification of a failure and bypasses the main valve for continued operation.

Question 51

Where is the limit sensor

Answer 51

Toward the top on the right side of the rotor system.

Question 52

Why is the limit sensor on the right side?

Answer 52

It’s the point with the most flapping and this best indicator of load.

Question 53

How much pressure is in the hydraulic system?

Answer 53

35 bar

Question 54

How is the upper hydraulic system powered?

Answer 54

MGB

Question 55

How is the lower hydraulic system powered?

Answer 55

V belt

Question 56

When does the limit light come on?

Answer 56

Exceeding loading limits on rotor Indicated failure of upper hydraulics Cyclic outside 10-88° quadrant

Question 57

When does the fuel filter light come on?

Answer 57

Fuel pressure at or below 0.7 bar