# CH.VIII.B — Powerplant Failure at Altitude in a Single-Engine Helicopter — Commercial Pilot Rotorcraft ACS

> CH.VIII.B from FAA-S-ACS-16, including the official objective, references, notes, and 24 exact knowledge, risk-management, and skill descriptions.

Canonical HTML: [https://www.check-ride.ai/acs/rotorcraft/commercial-pilot/ch-viii-b](https://www.check-ride.ai/acs/rotorcraft/commercial-pilot/ch-viii-b)

Site reference: [https://www.check-ride.ai/llms.txt](https://www.check-ride.ai/llms.txt)

## Official Task context

- FAA document: Commercial Pilot for Rotorcraft Category Helicopter Rating Airman Certification Standards
- Identifier: FAA-S-ACS-16
- Published source date: November 2023
- Aircraft category: Rotorcraft
- Certificate or rating: Commercial Pilot
- Area of Operation: Area of Operation VIII. Emergency Operations
- Task: Task B. Powerplant Failure at Altitude in a Single-Engine Helicopter
- Task code prefix: CH.VIII.B
- Official references: AC 61-140; FAA-H-8083-2, FAA-H-8083-21, FAA-H-8083-25; POH/RFM
- FAA source library: https://www.faa.gov/training_testing/testing/acs

## Official Task objective

To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with a simulated powerplant failure at altitude.

## Knowledge elements

- **CH.VIII.B.K1** — Elements of a powerplant failure at altitude.
- **CH.VIII.B.K2** — Effects of wind, weight, temperature, and density altitude.
- **CH.VIII.B.K3** — Main rotor (Nr) speed.
- **CH.VIII.B.K4** — Energy management.
- **CH.VIII.B.K5** — Causes and effects of high descent rates.
- **CH.VIII.B.K6** — Effect of varying bank angles, airspeeds, and rotor rpm.

## Risk management elements

- **CH.VIII.B.R1** — Low entry altitudes.
- **CH.VIII.B.R2** — Selection of landing area.
- **CH.VIII.B.R3** — Flight control inputs.
- **CH.VIII.B.R4** — Turbulence, including wake turbulence.
- **CH.VIII.B.R5** — Windshear.
- **CH.VIII.B.R6** — Low rotor rpm or rotor stall.
- **CH.VIII.B.R7** — Powerplant failure during the maneuver.
- **CH.VIII.B.R8** — Collision hazards.
- **CH.VIII.B.R9** — Autorotation power-off never-exceed speed (VNE) limitation.
- **CH.VIII.B.R10** — Helicopter trim.
- **CH.VIII.B.R11** — Distractions, task prioritization, loss of situational awareness, or disorientation.

## Skills elements

- **CH.VIII.B.S1** — Establish an autorotation.
- **CH.VIII.B.S2** — Establish power-off glide with the helicopter trimmed and autorotation airspeed, ±5 knots.
- **CH.VIII.B.S3** — Maintain main rotor (Nr) within normal limits.
- **CH.VIII.B.S4** — Select a suitable landing area considering altitude, wind, terrain, and obstructions.
- **CH.VIII.B.S5** — Maneuver to avoid undershooting or overshooting the selected landing area.
- **CH.VIII.B.S6** — Make radio calls as appropriate.
- **CH.VIII.B.S7** — Terminate approach with a power recovery at a safe altitude as directed by the evaluator.

## Difficulty methodology

Difficulty calibration is ongoing for this Task. Observed difficulty is a privacy-thresholded check-ride.ai mock-oral practice proxy, not an FAA practical-test pass or fail rate. Underlying sample sizes and the private reporting threshold are not published.

## Official Task notes

- Note: See Appendix 2: Safety of Flight and Appendix 3: Aircraft, Equipment, and Operational Requirements & Limitations for information related to this Task.

## Use in practice

A mock examiner can ask a pilot to explain the published elements, apply them to the configured aircraft and airport context, identify risks, and defend a decision. Practice prompts are not represented as actual FAA examiner scripts or predictions of the questions a candidate will receive.