Engine Inspection, Maintenance, and Troubleshooting
Core concepts
Know the types of inspections: preflight, postflight, progressive, phase, and annual/100-hour inspections. Understand borescope inspection, compression testing, oil analysis, and vibration analysis. Learn how to interpret engine instrument readings and correlate them with faults. Know the difference between a discrepancy and a defect, and the importance of logbook entries and return-to-service documentation. Study troubleshooting logic: verify the symptom, isolate the system, test the component, and confirm the repair. Understand the role of the maintenance manual and approved data.
Traps to expect
Questions often test whether you know that only approved data can be used for maintenance, and that a discrepancy must be recorded even if corrected. Watch for confusion between a compression test (cylinder condition) and an oil analysis (wear metals). Another trap is assuming a gauge reading is accurate; always verify with a known-good gauge. Also know that an annual inspection and a 100-hour inspection have similar scope but different applicability.
Worked example
If a cylinder compression test reads 45/80 psi, it is below the typical 60/80 minimum and requires investigation. Rule of thumb: compression below 60/80 or a leak past a valve or ring indicates a problem requiring further inspection.
Study habit
Use a systematic troubleshooting checklist for each system and practice writing a logbook entry that states the discrepancy, the action taken, and the reference used.