Which magneto check criterion includes both an RPM drop and a difference requirement, and is acceptable?

Which magneto check criterion includes both an RPM drop and a difference requirement, and is acceptable?

• A. Less than 110 RPM drop L/R and less than 50 RPM difference
• B. Less than 125 RPM drop L/R and less than 60 RPM difference
• C. Less than 150 RPM drop L/R and less than 70 RPM difference
• D. Less than 125 RPM drop L/R and less than 50 RPM difference

Answer: (D)

In magneto checks, you assess two things at once: how much RPM each magneto loses and how close the two magnetos stay to each other. The acceptable criterion is to have an RPM drop of less than 125 RPM on each magneto and a left-right difference of less than 50 RPM. This shows both mags are delivering power adequately and staying in balance. If either magneto drops more than 125 RPM, or the difference between the two sides exceeds 50 RPM, the readings are out of tolerance and indicate a possible issue that needs inspection. The other options impose either a stricter drop limit or a different difference limit that doesn’t satisfy both requirements together, so they don’t meet the accepted standard.

In magneto checks, you assess two things at once: how much RPM each magneto loses and how close the two magnetos stay to each other. The acceptable criterion is to have an RPM drop of less than 125 RPM on each magneto and a left-right difference of less than 50 RPM. This shows both mags are delivering power adequately and staying in balance. If either magneto drops more than 125 RPM, or the difference between the two sides exceeds 50 RPM, the readings are out of tolerance and indicate a possible issue that needs inspection. The other options impose either a stricter drop limit or a different difference limit that doesn’t satisfy both requirements together, so they don’t meet the accepted standard.