Powertrain And Rotor System

Question 1

Main module

Answer 1

Rigidly mounted to airframe by 8 bolts

Has a 3 degree forward tilt in main mast (rigid for lifting loads and 120kt attitude)

Transmission scavenge pumps are driven off the planetary gears, oil pressure in STEADY STATE flight should be 45-60psi sudden pressure drop by 10psi or more should be written up in the appropriate maintenance form)

Question 2

2 input modules

Answer 2

Input module changes the direction of the shaft input to the high speed shaft into the main module.

Has a hydraulic pump and generator on each module. Generator is cooled by transmission oil from main/input modules

Low pressure high temperature - land as soon as possible (slow to single engine airspeed, turn on APU, turn of generators)

Input into the input module has the free-wheeling unit on it

Question 3

Chip detectors

Answer 3

One on each transmission module, intermediate transmission, and tail rotor gearbox (5) (Main five pack) plus two others elsewhere.

Fuzz buildup can be burned. Each chip detector has a flow shutoff so that it may be removed for visual inspection without loss of oil.

Main mod chip detector has a 30 second delay, if the chip is still there, light will come on and you have to perform the EP (fuzz burner could not get it off)

(Input module chip - engine to idle, single engine airspeed, land as soon as possible)

Fuzz burn capability will be taken away if oil temp gets above 140*C. Disabling fuzz-burn off will NOT disable chip detection

A CHIP IBIT FAIL caution will appear after power up if any of the transmission chip detectors fail their PBIT

Question 4

Lubrication system

Answer 4

1 accessory module houses the oil pressure switch, if the pressure gets below 14psi it puts the caution light on

Transmission oil dipstick: pull out, clean, insert, pull out, read it (hot or cold)

Oil cooler and fan is driven by the tail-rotor driveshaft

Question 5

Rotors

Answer 5

Tail-rotor: 2 blades, 4 paddles

Main rotors are wider (wide chord blades) for better maneuverability

Inspect control rod bearings for damage/cracks

Primary servos to connect flight controls to rotor system are the for/aft/lateral

Tail rotor head blades canted 20*

Rotor brake hold main and tail rotor during engine start with engines at idle for 12-18 seconds with 150-180% at 40%NR during engine shutdown

Rotor brake solenoid locks the power control levers at idle