How to Keep Aircraft Airworthy

Keeping an aircraft airworthy is not just a legal requirement — it’s a matter of safety, performance, and operational reliability. Whether you operate a private plane, manage a fleet, or maintain aircraft professionally, understanding how to keep aircraft airworthy is essential for flight readiness and compliance with aviation authorities.

This guide outlines the key steps and best practices that ensure your aircraft remains safe, serviceable, and legally fit to fly.

Understand the Definition of Airworthiness

Airworthiness means the aircraft conforms to its type design and is in a condition for safe operation. This includes:

Meeting all maintenance and inspection requirements
Operating systems and equipment functioning properly
No unaddressed damage or defects
Required documents and certifications up to date

Regulatory bodies such as the FAA, EASA, or your local civil aviation authority define specific criteria for airworthiness. It’s your responsibility to stay in compliance at all times.

Perform Scheduled Inspections

Routine inspections are one of the most important ways to keep aircraft airworthy. These checks are required at specific time intervals based on flight hours, calendar time, or usage cycles.

Common inspection types:

Pre-flight inspection (pilot responsibility): Walkaround to check fuel, tires, controls, and surfaces
100-hour inspection (for rental or commercial aircraft)
Annual inspection (required for all U.S.-registered aircraft)
Progressive or phase inspections (used by fleet operators)
Special inspections (after hard landings, lightning strikes, etc.)

Always document inspections in the aircraft maintenance log and address any discrepancies before flight.

Stay Current with Maintenance Requirements

Preventive maintenance and corrective actions must be performed on schedule to ensure systems stay in optimal condition. Use your aircraft’s maintenance manual or manufacturer’s recommendations as your baseline.

Key maintenance tasks include:

Engine oil and filter changes
Brake pad and tire replacement
Propeller and control surface inspections
Avionics and instrument calibration
Battery checks and replacement
Corrosion treatment and cleaning

Unscheduled maintenance should be addressed promptly to prevent further damage and loss of airworthiness.

Comply with Airworthiness Directives (ADs)

Airworthiness Directives are legally enforceable rules issued by aviation authorities when a safety issue is discovered in a particular aircraft type, engine, propeller, or component.

To maintain airworthiness, you must:

Monitor ADs relevant to your aircraft model
Perform required actions by the specified compliance dates
Log completion of ADs in the maintenance records

Failure to comply with an AD automatically makes the aircraft unairworthy.

Keep Accurate and Complete Documentation

Proper recordkeeping proves that all maintenance, inspections, and directives have been completed. It’s also essential for resale, audits, and continued legal operation.

Your aircraft must have:

Airworthiness Certificate
Registration Certificate
Operating Handbook or POH
Weight and Balance data
Maintenance logbooks (airframe, engine, propeller)
Current list of complied Airworthiness Directives

Ensure all documents are accessible and updated after every service or inspection.

Use Certified Parts and Licensed Personnel

Only certified aviation parts and licensed mechanics (A&P, AME, LAME, etc.) should perform maintenance, especially tasks beyond basic preventive checks.

Guidelines to follow:

Install only FAA- or EASA-approved parts
Use licensed professionals for major repairs or inspections
Log technician license numbers in all maintenance entries
Avoid using undocumented or salvaged parts without traceability

Using unapproved components or unauthorized maintenance renders the aircraft unairworthy.

How to Keep Aircraft Airworthy

Perform Functional Tests and Operational Checks

After maintenance or component changes, always verify that the system functions as expected. These tests are part of return-to-service procedures and must be documented.

Systems that require regular testing:

Landing gear and brake systems
Electrical and lighting systems
Navigation and communication radios
Engine performance and throttle response
Flight control responsiveness

Functional checks catch issues that may not be visible during inspection.

Monitor Time-Limited Components and Life Cycles

Many aircraft parts have service life limits defined in hours, cycles, or calendar time. Keeping track of these limitations is critical to maintaining airworthiness.

Examples include:

Engine TBO (Time Between Overhaul)
Propeller overhaul cycles
Magneto inspection intervals
ELT battery expiration dates
Pitot-static and transponder testing schedules

Use maintenance tracking software or logbooks to monitor life-limited components accurately.

Store and Protect the Aircraft Properly

Aircraft that are parked or stored improperly can quickly become unairworthy due to environmental exposure, pests, or moisture.

Best storage practices:

Use hangars or covers to protect from UV and rain
Install control locks and tire chocks
Disconnect batteries if storing long-term
Perform preservation procedures for engines and fuel systems
Conduct a thorough inspection before returning to service

Environmental damage is one of the most preventable threats to airworthiness.

Train Pilots and Crew on Airworthiness Awareness

Pilots are the first line of defense in detecting airworthiness issues. They must understand their responsibility to assess aircraft condition before flight.

Training should include:

Pre-flight inspection procedures
Recognizing signs of mechanical or system problems
Logging discrepancies in the aircraft’s journey log
Knowing when to ground an aircraft

Educated pilots prevent accidents and protect the aircraft’s status.

Conclusion

Knowing how to keep aircraft airworthy is essential for safety, legal compliance, and efficient operation. From inspections and documentation to trained personnel and proper storage, each step plays a role in preserving the health and reliability of your aircraft. By following a disciplined, proactive approach, you reduce risks, lower maintenance costs, and keep your aircraft flight-ready at all times.