CH.VIII.I — Ground Resonance

What does ACS code CH.VIII.I cover?

ACS Code CH.VIII.I covers "Ground Resonance" under Area of Operation VIII (Emergency Operations) for the FAA Commercial Pilot Helicopter certificate (FAA-S-ACS-16). Candidates are tested on knowledge elements and risk management factors defined in 14 CFR regulations and FAA handbooks (PHAK / AFH).

Task Specification & Required References

• ACS Document: FAA-S-ACS-16 (Commercial Pilot Helicopter)
• Area of Operation: Area VIII — Emergency Operations
• Task: Task I — Ground Resonance
• Primary FAA Sources: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25), Airplane Flying Handbook (FAA-H-8083-3) / Helicopter Flying Handbook (FAA-H-8083-21), Aviation Weather Handbook (FAA-H-8083-28), 14 CFR Parts 61, 91 & 107, Aeronautical Information Manual (AIM).

Airman Certification Standards Elements

Knowledge Elements

• CH.VIII.I.K1: Exhibits knowledge of the elements related to ground resonance by describing:
• CH.VIII.I.K1a: a. Conditions that contribute to ground resonance
• CH.VIII.I.K1b: b. Preventive flight technique during takeoffs and landings
• CH.VIII.I.K1c: c. Landing surface
• CH.VIII.I.K2: Inspection of items that may contribute to ground resonance.
• CH.VIII.I.K3: Corrective actions during low and normal rotor rpm speeds.

Risk Management Elements

• CH.VIII.I.R1: Factors that may contribute to the onset of ground resonance.
• CH.VIII.I.R2: Recognition of the onset of ground resonance.
• CH.VIII.I.R3: Recovery procedure selection.

How do I study CH.VIII.I?

1. Read each element for CH.VIII.I in FAA-S-ACS-16 and note any you cannot explain in your own words.
2. Study each one in the FAA source it points to: the handbook chapter, the 14 CFR section or the AIM paragraph.
3. Practice with questions tagged CH.VIII.I, and read the explanation for every miss.
4. Retest, then review the ACS codes you still miss on your practice test report.

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Related ACS tasks

• Previous task: CH.VIII.H — Dynamic Rollover
• Next task: CH.VIII.J — Low Gravity (G) Recognition and Recovery
• Same area: CH.VIII.A — Powerplant Failure in a Hover in a Single-Engine Helicopter
• Same area: CH.VIII.B — Powerplant Failure at Altitude in a Single-Engine Helicopter
• Same area: CH.VIII.C — Approach and Landing with One Engine Inoperative (OEI) (Simulated)
• Same area: CH.VIII.D — Systems and Equipment Malfunctions
• Same area: CH.VIII.E — Vortex Ring State (VRS)
• Same area: CH.VIII.F — Low Rotor Revolutions Per Minute (RPM) Recognition and Recovery