MAG TEST FAILS...Am I done?

Introduction

This tutorial addresses what to do if your airplane fails the magneto check during pre-flight inspections. Understanding how to troubleshoot this situation can help you decide whether to continue your flight or seek maintenance.

Step 1: Conduct a Magneto Check

• Begin by performing a magneto check during the pre-flight inspection.
• Follow these steps:
  1. Start the engine and let it warm up.
  2. Set the throttle to a low RPM.
  3. Switch to the left magneto and monitor engine performance.
  4. Switch to the right magneto and observe any changes.
  5. Return to both magnetos and ensure everything is running smoothly.

Step 2: Identify the Issue

• If the magneto check reveals a failure, determine the nature of the problem:
  • Rough running engine: This could indicate fouled spark plugs.
  • Significant drop in RPM: This may also suggest spark plug issues or a malfunctioning magneto.

Step 3: Attempt to Clear the Spark Plugs

• If you suspect fouled spark plugs, try the following method:
  1. Increase the RPM to about 1,800 for a brief period.
  2. This higher RPM can help burn off any carbon deposits on the plugs.
  3. After a few moments, return to a low RPM and perform the magneto check again.

Step 4: Assess the Results

• After attempting to clear the plugs, re-check the magnetos:
  • If the engine runs smoothly and performs well on both magnetos, you may proceed with the flight.
  • If the issues persist, it’s best to ground the aircraft and consult maintenance.

Step 5: Document the Incident

• Keep a record of the magneto check results and any actions taken.
• This documentation is essential for maintenance records and can help technicians diagnose the problem more effectively.

Conclusion

In the event of a magneto check failure, it’s crucial to remain calm and methodical. By following these steps, you can troubleshoot and potentially resolve minor issues before deciding to seek maintenance. Always prioritize safety and never hesitate to ground your aircraft if you're unsure about its performance.