TD 27

Question 1

What is Transverse Flow Effect?

Answer 1

In forward flight, air passing through the rear portion of the rotor disk has a greater downwash angle than air passing through the forward portion. This is due to the fact the greater the distance air flows over the rotor disk, the longer the disk has to work on it and the greater the deflection on the aft portion. Downward flow at the rear of the rotor disk causes a reduced AOA, resulting in less lift. The front portion of the disk produces an increased AOA and more lift because airflow is more horizontal. These differences in lift between the fore and aft portions of the rotor disk are called transverse flow effect

Question 2

Rotor RPM Limitations

CONDITION POWER ON POWER OFF
Min Transient -
Min Cont
GM <= 2000 kg
GM >= 2000 kg
Max Cont
Partial Power
Torque <= 2x30% -
Max Transient

Answer 2

CONDITION POWER ON POWER OFF
Min Transient 85% -
Min Cont
GM <= 2000 kg 96% 80%
GM >= 2000 kg 96% 85%
Max Cont
Partial Power 104% 104%
Torque <= 2x30% 106% -
Max Transient 106% 110%

Question 3

WARNING LIGHT INDICATIONS - ROTOR RPM

Conditions/Indications

NRO low

• NRO ____ or less -
• Audio signal -

NRO high
- NRO ____ or above -
Audio signal at ____ or above -

Procedure

NRO low/NRO high

1. Rotor RPM indicator - Check
2. Collective lever -

Answer 3

NRO low

• NRO 95% or less - steady light
• Audio signal - low-pitch beeping tone

NRO high
- NRO 106% or above - flashing light and warning gong
Audio signal at 110% or above - flashing light and steady high pitch tone

Procedure

NRO low/NRO high

1. Rotor RPM indicator - Check
2. Collective lever - Adjust as necessary to maintain NRO within normal range

Question 3

WARNING LIGHT INDICATIONS - ROTOR RPM

Conditions/Indications

NRO low

• NRO ____ or less -
• Audio signal -

NRO high
- NRO ____ or above -
Audio signal at ____ or above -

Procedure

NRO low/NRO high

1. Rotor RPM indicator - Check
2. Collective lever -

Answer 3

NRO low

• NRO 95% or less - steady light
• Audio signal - low-pitch beeping tone

NRO high
- NRO 106% or above - flashing light and warning gong
Audio signal at 110% or above - flashing light and steady high pitch tone

Procedure

NRO low/NRO high

1. Rotor RPM indicator - Check
2. Collective lever - Adjust as necessary to maintain NRO within normal range

Question 4

Tail rotor drive failure - hover
Conditions/Indications
Complete loss of tail rotor thrust
– Tail rotor failure in power-on flight is indicated by a yawing motion nose right; the yaw rate depends on the aircraft power at the time of failure.
Procedure
F HOVER IN GROUND EFFECT
1. Both Twist grips –
and simultaneously:
2. Landing attitude – 
3. Collective lever – 
After landing:
4. Double engine emergency shutdown –

Answer 4

Tail rotor drive failure - hover
Conditions/Indications
Complete loss of tail rotor thrust
– Tail rotor failure in power-on flight is indicated by a yawing motion nose right; the yaw rate depends on the aircraft power at the time of failure.
Procedure
F HOVER IN GROUND EFFECT
1. Both Twist grips – Rotate to IDLE
and simultaneously:
2. Landing attitude – Establish
3. Collective lever – Apply as necessary
After landing:
4. Double engine emergency shutdown – Perform