Maintenance Practices, Inspection, and Documentation
Core concepts
Candidates must understand maintenance documentation: logbooks, work orders, inspection records, airworthiness directives, service bulletins, and approved data. Know the difference between a maintenance release, a certificate of airworthiness, and an annual inspection. Understand inspection types: preflight, post-flight, progressive, phased, and special inspections. Know the role of nondestructive testing: visual, dye penetrant, magnetic particle, eddy current, ultrasonic, and radiography, and when each is appropriate. Understand torque procedures, calibration of tools, and the importance of recording serial numbers and part numbers. Know the concept of return to service and who is authorized to sign it.
Traps in questions
A frequent trap is confusing a service bulletin (advisory) with an airworthiness directive (mandatory). Another is assuming any mechanic can return any aircraft to service; authorization depends on rating and scope. Watch for questions on inspection intervals: they are based on calendar time, flight hours, or cycles, and the most restrictive applies. Also remember that a maintenance record must be made at the time of work, not reconstructed later.
Worked example / rule of thumb
Rule of thumb: if an AD and a service bulletin address the same component, the AD is mandatory and the SB is advisory unless the AD incorporates it. If an AD requires compliance within 100 flight hours and the aircraft has 40 hours since the last check, the remaining time is 60 hours. Always record the AD number, method of compliance, and date in the maintenance record.