TRANSMISSION SYSTEM

Question 1

The primary function of the transmission system is to…

Answer 1

take the combined power from the two engines
reduce the rpm
transfer it to the main and tail rotors

Question 2

The secondary function is to…

Answer 2

provide a drive for electrical and hydraulic power generation.

Question 3

The tail drive shaft consists of ___ sections with a disconnect coupling at the
fold hinge

Answer 3

6

Question 4

The shafts are ____ tolerant and suspended at ___ points by viscous-damped bearings

Answer 4

ballistically
4

Question 5

MGB forward tilt

Answer 5

3°

Question 6

Input module purpose is to…

Answer 6

take the power delivered by the Np turbine
change the angle of drive
transfer power to the main module
provide drive for the respective accessory module.

Question 7

The input module contains a ____ ____, which allows each engine to be disengaged from the transmission when Nr exceeds Np (autorotation) and during single-engine operations

Answer 7

freewheeling unit

Question 8

The accessory modules are driven by the ___ output
shaft during normal operations or back-driven by the ____ ____ during single-engine operations or autorotative flight

Answer 8

engine
main module

Question 9

The engine output shaft provides drive from the engine to the input module via the diaphragm coupling. The diaphragm coupling is designed to allow for slight _____ or ____ misalignment of the engine output shaft during
operation

Answer 9

angular
axial

Question 10

What kind of lubrication does the IGB have?

Answer 10

splash-lubricated

Question 11

What kind of lubrication does the MGB have?

Answer 11

pressure lubricated

Question 12

What kind of lubrication does the TGB have?

Answer 12

splash-lubricated

Question 13

The IGB does the following functions:

Answer 13

transmits torque
reduces shaft speed from the MGB to the Tail Gearbox (TGB)
changes the angle of drive

Question 14

The TGB does the following functions:

Answer 14

changes the angle of drive
provides gear reduction

Question 15

The TGB enables ___ changes of the tail rotor blades through the flight control system and has a built-in ___ left tilt

Answer 15

pitch
20°

Question 16

The main transmission incorporates an integral ___ ___ lubrication system that provides ___ , ___ oil to all main transmission bearings and gears

Answer 16

wet sump
cooled, filtered

Question 17

The ac generators on the accessory modules also use
___ ___ for cooling

Answer 17

transmission oil

Question 18

Can the MGB filter be bypassed?

Answer 18

Yes

Question 19

A thermal lockout prevents the PDI from
___ ___ ___ in cold ambient conditions

Answer 19

extending during starts

Question 20

The oil cooler uses a blower, driven by the ___ ___ ___, to
cool the oil before it enters the various modules

Answer 20

rotor drive shaft

Question 21

MAIN XMSN PRESS LOW comes from what sensor? What PSI threshold?

Answer 21

sensor on the No. 1 accessory module, the farthest point from the pumps
14psi

Question 22

An oil temperature sensor at the ___ ___ input to the MGB manifold activates the MAIN XMSN OIL HOT caution when the main transmission oil
temperature goes above ___ .

Answer 22

oil cooler
117 ºC

Question 23

MGB pressure readings for the vertical instruments are taken at the ___ manifold inlet

Answer 23

MGB

Question 24

MGB temperature for the vertical instruments is sensed in the ___ using a temperature sensor that is embedded into the main module ___ ___ ___

Answer 24

sump
sump chip detector

Question 25

The fuzz burnoff feature is deactivated when oil temperature is above ___; however, magnetic detection will remain

Answer 25

140°C

Question 26

The chip detector for the main module sump rests in the lowest point
of the oil system and incorporates a ___ time delay to further eliminate false warnings

Answer 26

30-second

Question 27

The chip detector for the main module sump contains an embedded oil temperature sensor that provides oil temperature
readings to the ___ ___.

Answer 27

cockpit display

Question 28

The IGB and TGB contain identical chip detectors that contain an embedded oil ____ switch

Answer 28

temperature

**indicate when a chip is present and/or the gearbox oil temperature is high

Question 29

The CHIP IBIT takes approximately ____ to verify circuitry and checks the individual chip detectors. For approximately the first ____ of the test, 28 Vdc is interrupted and WCAs and MASTER CAUTION lights will not correctly respond

Answer 29

2 minutes
40 seconds