Aviation Dictionary

Propeller/rotor modulation error

Certain propeller rpm settings or helicopter rotor speeds can cause the VOR course deviation indicator (CDI) to fluctuate as much as ±6°. Slight changes to the rpm setting will normally smooth out this roughness.

Dictionary Term

Propeller/rotor modulation error

Definition

Certain propeller rpm settings or helicopter rotor speeds can cause the VOR course deviation indicator (CDI) to fluctuate as much as ±6°. Slight changes to the rpm setting will normally smooth out this roughness.

References

Pilot's Handbook of Aeronautical Knowledge · Federal Aviation Administration · 2023