Main & Tail Rotor Systems

Question 1

When does the Main Gearbox Oil Hot caution light illuminate?

Answer 1

130 degrees C

Question 2

If you experience a loss of oil pressure in the MGB will the oil temperature be reliable?

Answer 2

NO- The main gearbox oil temperature sensors are “wet bulb” systems which require some presence of oil to indicate properly. When MGB oil pressure is completely lost MGB temperature indications are not reliable.

Question 3

If an EMERGENCY DECENT is performed what minimum TQ you would set in the event of a MGB Oil pressure/temperature issue?

Answer 3

At least 15%

Question 4

What is the purpose of the Mixing Unit?

Answer 4

Reduces pilot workload by adding required pitch, roll, and yaw outputs as a result of collective inputs

1. Collective to Roll (Translating Tendency)
2. Collective to Pitch (compensates for the effects of changes in rotor downwash on the horizontal stabilizder)
3. Collective to Yaw (Anti-Torque)
4. Yaw to Pitch (Corrects for vertical lift of Tail Rotor)

Question 5

What is the vertical lift component of the tail rotor?

Answer 5

4%

Question 6

During start and shutdown at what Nr should Droop stops be out during run-up and be back in during shutdown?

Answer 6

By 70-75% they should be out during run-up and in 50% during shut down

Question 7

What is the minimum transient Nr during OEI landing?

Answer 7

80%

Question 8

When can you use the Rotor Brake?

Answer 8

Normal shut down – <40% Nr, and up to 105% Nr in Emergencies

Question 9

Should you experience a TR QUAD with loss of heading control what airspeeds provide a balance of forces and why?

Answer 9

Yaw force is less at 30 & 150 KIAS because a centering spring will set 10.5° of positive TR pitch.

Question 10

How are main rotor vibrations controlled?

Answer 10

Bifilar- counteracts and cancels the vibratory forces at the main rotor before they can be felt within the airframe
Active Vibration Control (AVC)