In this lesson, the student will understand the flight conditions leading to Vortex Ring State, to recognize the symptoms and to apply the correct recovery action.
- Brief Vortex ring state with emphasis on the requirements for Vortex Ring State, how to recognize the onset and flight conditions that could lead to the helicopter entering Vortex Ring State.
- Climb to a safe altitude, at least 1500ft AGL, conduct HASELL CHECKS
- Demonstrate Vortex ring state:
- Slowly bleed off the speed whilst maintaining a power setting just below that required for a HOGE
- When the speed decreases to 30kts, indicate to the student the onset of a ROD
- As the speed decreases through 20kts, indicate the onset of Vortex Ring State by drawing the student’s attention to the rapid increase in ROD, onset of random yawing, shaking and decreased effectiveness of cyclic.
- Initiate the recovery by lowering the nose, to increase forward speed
- Point out to the student how the recovery happens almost instantaneously as speed increases through 20Kts
- Climb again to a safe altitude, conduct HASELL CHECKS, re-enter Vortex ring state
- Initiate the recovery by lowering the collective fully to enter autorotation, then increasing speed with forward cyclic.
- Point out to the student the excessive height loss with this method of recovery.
- The student must climb again to a safe altitude, conduct HASELL CHECKS, and demonstrate re-entry of Vortex ring state, his/her ability to recognize the onset and recovery from Vortex Ring State.
At the completion of this exercise the student must be able to positively recognize the onset of Vortex Ring State and recover safely with minimal height loss. They need to understand the flight conditions leading to vortex ring state, and how to safely manage speed and ROD in these conditions to avoid the onset.