Chapter 2.3 & 2.4 Transmission System & Fuel

Question 1

Describe all the modules in the Main Transmission

Answer 1

-Main Module: 3* forward tilt, supports and drives the Main Rotor, contains Oil Sump/Filter/Oil temp/px/chip detector
-Input Module: input bevel pinion gear provides 1st gear reduction
-Freewheeling Unit: allows for disengagement of engine to XMSN if Np > Nr
(a) Diaphragm Coupling: allows for slight angular or axial misalignment
(b) Warning: any abnormal/loud whining noises during rotor engagement may be failed diaphragm
-Accessory Module: provides mounting and drive to the AC Generators AND hydraulic pump module
(a) Right Accessory Module: Nr sensor for Vertical Instruments
(b) Left Accessory Module: TDI and Low Oil PX

Question 2

Tail Rotor Drive Shaft has how many sections and how many viscous-damped bearings

Answer 2

6 ballistically tolerant sections and 4 viscous damped bearings

Question 3

IGB and TGB functions and descriptions

Answer 3

-IGB: splash lubricated, reduces speed from MGB to TGB and changes angle of drive

-TGB: splash lubricated, reduces speed from IGB to TGB and drives the tail rotor

Question 4

How many chip detectors are in the Main Module + IGB and TGB
What is deactivated at 140*C
What is special about the Main Module Chip

Answer 4

-5+1+1
-burn off feature
-Has an additional 30 second delay sensor

Question 5

How long does the Chip IBIT last, what is disabled?

Answer 5

2 min, WCA and caution advisories are disabled for 40 secs

Question 6

Describe the fuel system

Answer 6

crashworthy, suction-type, ⅓ self sealing with 590 gallons (~4012 lbs of JP-5)
2 cells interconnected at 270-600lbs

Question 7

What components are part of the Left and Right Tank

Answer 7

Left Tank: Refueling Ports, 2 High Level Shutoff Valves, sump drain, check valve
Right Tank: 2 check valves, sump drain, APU fuel line, Fuel Dump System

Question 8

Uneven refueling between the tanks may cause what? And when do you stop the refueling

Answer 8

Stop Fueling if cells are filling unevenly (1700 lbs) because it may cause the tanks to rupture

Question 9

Types of refueling
What’s PX refueling rated to
What’s HIFR rated to

Answer 9

Gravity: may be fueled in any order and is NOT allowed with Engine/APU running due to static electricity
Single-Point PX Refueling: 55 psi. Fills Main-Right-Left. Prechecks (A/B) check high level sensors
HIFR: 20 psi refueling but can filter particle and water

Question 10

Automatic Refuel commences when?
When should you test manual fuel transfer?
Do not initiate unmonitored manual fuel transfer until when?

Answer 10

Automatic Refuel: 2640 lbs
Do NOT initiate unmonitored manual transfer until < 3200 lbs. Check once 300 lbs (tbh check after launch to not forget)

Question 11

Define Primary Fuel
List them

Answer 11

Fuel that is authorized for continuous unrestricted operations
JP-5, JP-8, F-24

Question 12

Define Restricted Fuel
What are the restrictions

Answer 12

Flight that imposes operational restrictions
1. Single Engine Training is Prohibited
2. Next 2 refuels SHALL be treated as if mixed
3. Operational characteristics are different
4. Takeoffs SHALL stabilize without Fuel Pressure for 10 seconds before transitioning to forward flight

Question 13

Define Emergency Fuel

Answer 13

Fuel which may be used when primary or restricted fuel are not available for emergency or operational necessity