Powertrain System Flashcards
The main transmission system changes the engine RPM to a usable rotor RPM of ____ gear reduction
20.4 : 1 gear reduction
The transmission allows auto rotation through the use of a ____.
Free wheeling unit (sprag clutch)
What are the 5 cases on the main transmission?
Top Case Planetary Case Main Case Support Sump case
What components are mounted on and driven by the transmission? (4)
Nr tachometer
Hydraulic pump
DC generator
Rotor Brake
Do not apply rotor break above ___% Nr
20%
WARNING: Applying rotor break above ___% Nr will increase tendency for aircraft to spin on smooth surfaces
40%
This component lifts the airframe and is attached to bottom of the transmission and the airframe lift beam
Lift link
The Th-1H has ___ chip detectors in the main transmission.
3
One in the upper mast, one in the planetary area, and one in the sump/oil area
The ____ is required for ground run and flight
Structural tube
The oil system has a thermal bypass valve which causes the oil to bypass the cooler when oil reaches below ____ degrees C
54.4 degrees C
How many driveshaft make up the tailrotor driveshaft?
Hangar bearings?
6 driveshafts (one short 18 inches long)
4 hangar bearings
How many vibration isolation mounts are found on the transmission?
5
What is the gear ratio of the 90 degree gearbox?
reduces RPM 2.6 : 1 and changes angle of drive
The 42 degree gearbox provides ___ gear reduction and changes angle of drive
No
How many chip detectors are in the transmission and gearboxes?
5
