DQ27 Flashcards
(4 cards)
What is Transverse Flow Effect?
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 fack the greater 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 horisontal. These differences in lift between the fore and the aft portions of the rotor disk are called transverse flow effect. This effect causes unequal drag in the fore and aft portions of the rotor disk and results in vibration easily recognizable by the aviator. it occurs between 10 and 20 knots. Gyroscopic precession causes the effects to be manifested 90 degrees in the direction of rotation, resulting in a right rolling motion.
WARINING LIGHT INDICATIONS — ROTOR RPM
NRO low
- NRO ______ or less - _____________
- Audio signal - _____________
NRO high
- NRO ______ or above- _____________
- Audio signal at _____ or above - _____________
Procedure
NRO low/NRO high
- Rotor RPM indicator - Check
- Collective lever - ________________
WARINING LIGHT INDICATIONS — ROTOR RPM
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
- Rotor RPM indicator - Check
- Collective lever - Adjust as necessary to maintain NRO within normal range
Tail rotor drive failure - hover
Procedure - HOVER IN GROUND EFFECT
1. Both Twist grips – ___________
and simultaneously:
2. Landing attitude – ___________
3. Collective lever – _______________
After landing:
4. Double engine emergency shutdown – ___________
Tail rotor drive failure - hover
Procedure - 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
