Ch 7- Transmissions

Question 1

How does the manufacturer align the transmission on the bell 206

Answer 1

String method?

Question 2

What gears are used on the bell 206

Answer 2

• spiral bevel
• planetary
• sun
• fixed
• crown

Question 3

What 3 accessories are there on the bell 206

Answer 3

• Transmissions oil pump
• Hydraulic oil pump
• rotor tach generator

Question 4

26 Qs

Answer 4

31 marks

Question 5

What is the purpose of a clutch?

Answer 5

To unload the engine during starting operation because the inertia required to move the rotor system would be too great

Question 6

Which engines require a clutch?

Answer 6

Reciprocating engines and turbine powered helicopters that don’t use a free turbine

Question 7

Why is it necessary to have a free wheel?

Answer 7

It allows the engine to drive the transmission and prevent the rotor from driving the engine. It allows for autorotation in the event of engine seizure

Question 8

Name the types of freewheelings

Answer 8

Sprag clutch
-freewheeling unit
-overrunning clutch
Ramping roller

Question 9

What is the main purpose of a transmission?

Answer 9

It’s a gear reduction mechanism attached to the adapter plate at the upper end of the engine

Question 10

What accessories are driven off of Bell 206 main Transmissions?

Answer 10

• transmission oil pump
• hydraulic pump
• rotor tachometer generator

Question 11

Lubrication system on Hughes 500 and Bell 206 freewheels

Answer 11

Hughes 500
-self-contained oil system
Bell 206
-lubricated by transmission oil system