Settling with Power (VRS)

The three conditions — refresher

All three must be present at the same time:

1. Powered descent at 20-100% of available engine power.
2. Descent rate ≥ 300 fpm — the threshold varies with gross weight, rotor RPM, and density altitude. At max gross weight or low rotor RPM, VRS can develop at lower descent rates.
3. Airspeed below ETL — typically below ~30 kt in still air. Headwind raises this threshold (helps); tailwind lowers it (hurts).

The CPL nuance the PPL doesn't always cover: low rotor RPM aggravates the condition. A rotor that's drooped 5% under high collective demand has less margin and enters VRS at lower descent rates. Watch the RPM gauge during high-power-demand phases of flight.

The five operational scenarios where it kills

Almost every VRS accident traces back to one of these:

1. Steep approach with high descent rate — pilot tries to clear an obstacle on short final, lets the descent rate build past 300 fpm, and arrives at the LZ slow and sinking. Most common civilian VRS scenario.
2. Downwind approach — the apparent groundspeed feels normal, but the airspeed is much lower than the pilot perceives. The helicopter is below ETL while the ground says "you're moving." Most common confined-area VRS scenario.
3. Formation flight in a leader's downwash — wingman flies into the column of disturbed air the leader produced. Conditions for VRS arrive without the pilot doing anything wrong. Military and EMS multi-ship operations.
4. OGE hover at performance limit — pilot tries to hover OGE at a weight/DA combination that's at or beyond the chart limit. Helicopter can't quite hold altitude, descent rate creeps up, VRS sets in.
5. Photo / sling-load operations — slow flight near an object, often with limited maneuver options. Pilots task-focus on the work and lose track of airspeed and descent rate.

Early recognition — the operational standard

The PPL student learns to recognize VRS once it's developed. The CPL standard is to see the conditions assembling and abort before VRS sets in.

Your scan during high-risk phases (slow approach, OGE work, downwind operations):

• Airspeed — staying above ETL? If not, why are you slow?
• Descent rate — under 300 fpm? If approaching that number with airspeed already low, abort the approach and re-fly.
• Collective response — does pulling collective produce the expected climb? If response feels mushy or absent, treat it as VRS prelude.
• Vibration — building low-frequency rumble means rotor tip vortices are reaching the disc.

The discipline: any time your scan shows two of those flags during a slow descent, recover before the third arrives. Pilots who wait for full VRS development run out of altitude.

The standard recovery

The book recovery, taught at every flight school and required on the ACS:

1. Lower collective slightly — stop adding to the recirculating downwash.
2. Forward cyclic — gain airspeed, fly out of the disturbed-air column.
3. As airspeed builds through ETL, the rotor finds clean air, lift returns.
4. Recover with collective.

Cost: typically 100-500 ft altitude loss. The recovery is universally applicable (works for any helicopter, any rotation direction) but it's altitude-expensive. If you noticed VRS at 200 AGL on approach to a confined area, the standard recovery puts you in the trees.

The Vuichard recovery

Claude Vuichard, a Swiss helicopter pilot, developed an alternative recovery in the 1990s that has been increasingly adopted as the preferred method, especially for low-altitude entries. The Vuichard recovery exits the disturbed air column laterally instead of flying forward through it.

For a US (CCW main rotor) helicopter:

1. Raise collective to maximum continuous power.
2. Right cyclic — about 10-20° of lateral bank.
3. Left pedal as needed to maintain heading against the increased torque.

The aircraft slides sideways out of the disturbed air column in 1-3 seconds. The advancing blade (right side of disc on a CCW rotor) is moving into clean undisturbed air; combined with the lateral acceleration, the rotor finds lift much faster than the standard recovery's forward acceleration provides.

Reported altitude loss: often under 50 ft — an order of magnitude better than the standard recovery.

For CCW-rotor helicopters (most European designs — Eurocopter family), the lateral inputs reverse: left cyclic, right pedal. Same principle, mirrored.

Which to teach, which to use

The honest answer: both, in the right context.

• Standard recovery — universally applicable, on the ACS, no retraining required, lots of altitude loss. Right for: high-altitude entries, training, the checkride.
• Vuichard recovery — much less altitude loss, requires retraining, direction reverses for CW rotors. Right for: low-altitude entries, operational pilots who've trained the technique.

The CPL pilot should know both, understand when each is appropriate, and not freeze under task load trying to remember which one their instructor told them about. Drill both during recurrent training.

Avoidance — the operational discipline

Recovery is for failure mode. Avoidance is the daily practice:

• Never let descent rate exceed 300 fpm below ETL — full stop. If the approach demands it, the approach is wrong.
• Brief downwind approaches as carefully as max-perf takeoffs — they're at least as risky.
• Verify OGE hover capability at destination before committing to a confined approach.
• In formation, never fly through the wake of a preceding helicopter at slow speed.
• Watch rotor RPM during high-power demand phases. Drooping rotor narrows VRS margin.