Transmission Flashcards
NATOPS Chap 2
Transmision System
The primary function of the Transmission system is?.
“To take the combined power from the two engines, reduce the rpm, and transfer it to the main and tail rotors”
NATOPS Chap 2
Transmision System
The secondary function of the transmission is?
“to provide a drive for electrical and hydraulic power generation”
NATOPS Chap 2
Transmision System
What does the transmission power train consist of?
Main transmission modules, tail rotor drive shaft, oil cooler, intermediate gearbox, and tail gearbox.
NATOPS Chap 2
Transmision System
How many sections does the tail drive shaft consist of?
It consists of 6 sections with a disconnect coupling at the fold hinge. The shafts are ballistically tolerant and suspended at four points by viscous damped bearings. The oil cooler is an integral part of the tail rotor drive shaft system
NATOPS Chap 2
Transmision System
What are the 5 modules the Transmission consists of?
Two accesory modules, two input modules, and one main module (this has a 3* forward tilt).
NATOPS Chap 2
Transmision System
Where is the Util hydraulic pump located
on the right rear quadrant of the main transmission
NATOPS Chap 2
Transmision System
Describe the oil system of the main gearbox…
“pressure lubricated with a oil sump, oil filter, oil temp/px/chip indication systems”
NATOPS Chap 2
Transmision System
What do the Input modules contain?
input bevel-pinion gear and a freewheeling uint. The Freewheeling unit allows each engine to be disengaged from the transmission when Nr exceeds Np. The Input Module provides the first gear reduction between the engine and the main module
NATOPS Chap 2
Transmision System
What connects the engine and the input mod?
The diaprahgm coupling connects the two and allows for slight angular or axial misalignment of the engine output shaft during operation
NATOPS Chap 2
Transmision System
What are attached on the Accessory Mods
The accessory mods provide mounting for hydraulic pumps, generators, and Nr tachometer (#2 side), Low oil px sensor and TDI (#1 side)
NATOPS Chap 2
Transmision System
How are the Intermediate and tail gearbox lubricated?
Splash type
NATOPS Chap 2
Transmision System
Main Tranmission lubrication system incorporates…
“integral wet sump lubrication system that provides: cooled, filtered oil to all bearings and gears.”
NATOPS Chap 2
Transmision System
What also uses cooled transmission oil?
both generators
NATOPS Chap 2
Transmision System
MAIN XMSN OIL HOT advisory
Oil temp is > 105 and OIL HOT caution is not activated
NATOPS Chap 2
Transmision System
XMSN Px LOW advisory
Oil Px is <= 30psi, Nr is >= 25%, and XMSN Px low caution is not activated
NATOPS Chap 2
Transmision System
XMSN Px Hi advisory
Oil Px is btwn 65 and 130
NATOPS Chap 2
Transmision System
XMSN OIL HOT caution
temp >117
NATOPS Chap 2
Transmision System
XMSN Px LOW caution
Px < 14 psi
NATOPS Chap 2
Transmision System
How many chip detectors does the system have?
5 in the MGB
1 in the IGB
1 in the TGB
NATOPS Chap 2
Transmision System
How does the burnoff feature work?
Each chip detector has a burn off feature which eliminates false warnings created by fuzz and minute particles. The feature is deactivated when oil temp is above 140*
NATOPS Chap 2
Transmision System
What does the detector in the main module contain/incorporate?
An embedded temp sensor as well as a 30 sec time delay to further eliminate false warnings
NATOPS Chap 2
Transmision System
At what temp does INT XMSN/TAIL XMSN OIL HOT appear?
When oil temp is 140*. This is measured at the chip detector which contains an embedded temp switch
NATOPS Chap 2
Transmision System
Explain the CHIP IBIT
The test takes approx 2 min to go away, and for the first 40 sec, 28VDc is interrupted and WCAS and Master lights will not work.
NATOPS Chap 2
Transmision System
What sensors are attached to the Transmission?
Nr sensor for vids—> Right side
Nr sensor for the TDI—> left side
NATOPS Chap 2
Transmision System
What is the degree of tilt for the TGB?
The TGB enables pitch changes of the rotor blades through the flight control system and has a built-in 20* left tilt
NATOPS Chap 2
Transmision System
CAUTION: Abnormal/Loud whining hoise heard during rotor engagement…
“If an abnormal or loud whining noise is heard during rotor engagement, shut down engine immediately. Whining noise may be an indication of a pending diaphragm coupling failure. Do not operate engine until appropriate troubleshooting has been performed to locate the source of the whining noise. If incorrect installation of diaphragm coupling is the source of the whining noise, further engine operation could result in diaphragm coupling failure”
NATOPS Chap 2
Transmision System
How does the Oil Cooler work?
It uses a blower, driven by the rotor drive shaft, to cool the oil before it enters the various modules
