Aircraft Maintenance Requirements

Regular maintenance of an aircraft is crucial for ensuring its airworthiness and compliance with Federal Aviation Regulations (FARs). This guide outlines the key maintenance requirements, inspections, and documentation needed to keep an aircraft in safe operating condition.

1. Required Inspections

The FARs mandate certain inspections and maintenance to keep an aircraft airworthy. These inspections must be completed at specific intervals.

1.1 Annual Inspection

• Frequency: Once every 12 calendar months.
• Who Can Perform: A certified Airframe and Powerplant (A&P) mechanic with an Inspection Authorization (IA).
• Applicability: Required for all aircraft, except those operating under a progressive inspection program.

1.2 100-Hour Inspection

• Frequency: Every 100 hours of flight time.
• Who Can Perform: A certified A&P mechanic (IA not required).
• Applicability: Required for aircraft used for hire or flight instruction. Private-use aircraft are exempt unless used commercially.

1.3 Progressive Inspection

• Purpose: Replaces the annual and 100-hour inspections with phased inspections at shorter intervals.
• Applicability: Approved by the FAA and typically used by operators to minimize aircraft downtime.

1.4 Altimeter and Pitot-Static System Inspection

• Frequency: Every 24 calendar months.
• Applicability: Required for IFR operations.

1.5 Transponder Inspection

• Frequency: Every 24 calendar months.
• Applicability: Required for all aircraft operating in controlled airspace requiring a transponder.

1.6 Emergency Locator Transmitter (ELT) Inspection

• Frequency: Every 12 calendar months.
• Battery Replacement: Required after 50% of the battery’s useful life or 1 cumulative hour of use.

2. Airworthiness Directives (ADs)

Airworthiness Directives (ADs) are legally enforceable rules issued by the FAA to correct unsafe conditions in aircraft, engines, propellers, or appliances.

• Compliance: ADs must be complied with as specified (e.g., immediately, at the next inspection, or within a certain timeframe).
• Responsibility: The aircraft owner/operator is responsible for ensuring compliance with applicable ADs.

3. Preventive Maintenance

Preventive maintenance can be performed by private pilots on aircraft they own or operate, as specified in FAR Part 43 Appendix A.

3.1 Examples of Preventive Maintenance

• Changing engine oil.
• Replacing spark plugs.
• Replenishing hydraulic fluid.
• Replacing landing light bulbs.

4. Required Maintenance Records

Aircraft maintenance records must be kept to document all inspections, repairs, and alterations.

• Airframe, Engine, and Propeller Logs: Document inspections, repairs, and overhauls.
• AD Compliance Records: Show compliance with applicable ADs.
• ELT Records: Include inspection dates and battery replacements.

5. Minimum Equipment List (MEL) and Inoperative Equipment

Not all equipment on an aircraft must be operational for it to be considered airworthy. The Minimum Equipment List (MEL) or FAR 91.213 governs operations with inoperative equipment.

5.1 MEL

• Purpose: Specifies equipment that may be inoperative and still allow flight operations.
• Applicability: MELs are specific to an aircraft and must be approved by the FAA.

5.2 Inoperative Equipment (Without MEL)

• Determine if the equipment is required by:
  • The aircraft’s type certificate.
  • FAR 91.205 (required equipment for day/night or IFR/VFR operations).
  • An AD.
• If not required, the equipment must be deactivated and placarded “Inoperative.”

6. Common Maintenance Acronyms

Acronym	Meaning
AVIATE	Required inspections: Annual, VOR (30 days for IFR), 100-hour, Altimeter (24 months), Transponder (24 months), ELT (12 months)
ARROW	Required documents: Airworthiness certificate, Registration, Radio license (international), Operating limitations, Weight and balance

7. Conclusion

Aircraft maintenance requirements are essential to ensure airworthiness, safety, and regulatory compliance. Regular inspections, adherence to ADs, proper documentation, and preventive maintenance are the responsibility of every aircraft owner and operator. By staying informed and organized, pilots can ensure their aircraft remains safe and ready for flight.