How often are airliners inspected and maintained?

In this article · 7 sections

No single number, on purpose
What the rules require
Where the intervals come from
Checking that it works
Older airplanes get extra reviews
What this means for your flight
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No single number, on purpose

People often ask "how often is a plane inspected?" expecting one answer, like a car's annual check. Airliners don't work that way. Each part of the airplane has its own schedule, depending on how it wears.

What the rules require

Every US airline flying under Part 121 must have an inspection program and a program covering other maintenance, and those programs must ensure that work is done according to the airline's manual, by competent people with proper facilities, and that each aircraft released to service is airworthy.¹

The FAA's guidance on these programs explains what goes into the schedule: airworthiness directives, manufacturer service bulletins, replacement of parts with a fixed life, overhauls, special inspections, checks and tests, lubrication and servicing, and tasks identified by the type's Maintenance Review Board.⁴

Where the intervals come from

Most modern airliners get their starting maintenance schedule from a structured industry process (called MSG-3) that manufacturers use to work out what scheduled maintenance each system needs. The initial intervals are based on knowledge of the design and the judgment of the review group, and then validated with real operating data once the type is in service.⁴

Checking that it works

Airlines must also run a continuing analysis and surveillance system: an ongoing check of whether their inspection and maintenance programs are actually effective, with a way to correct any deficiency.² The FAA's guidance describes this as how an airline judges whether its scheduled maintenance is doing its job.⁴

Older airplanes get extra reviews

Age-sensitive parts get special attention. Under the FAA's aging-airplane rule, an airline may not keep flying an airplane past set dates unless the FAA has completed an inspection and records review showing that the maintenance of age-sensitive parts has been adequate and timely. For newer airplanes the first one is due within 5 years after the start of the 15th year in service, and they repeat at intervals of no more than 7 years.³ The records reviewed include total flight hours and cycles, life-limited parts, structural repairs and the status of every airworthiness directive.³

What this means for your flight

An airplane at the gate is released to service only when it's airworthy under that program.¹ If a crew or mechanic finds an issue before departure, fixing it can cause a maintenance delay. Annoying, but it's the system working.

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Quick answers

How often do airlines inspect their planes?

Each US airline must have an inspection program and a maintenance program, and each task in it has its own interval. Intervals are set from the manufacturer's maintenance planning data and adjusted as the airline collects real service data.

Are old airplanes inspected more?

Yes. US rules add an aging-airplane inspection and records review by the FAA within about 5 years of an airplane entering its 15th year of service, then at intervals of no more than 7 years.

What are airworthiness directives?

FAA orders, issued under 14 CFR Part 39, that require a specific inspection, fix or change on a type of aircraft, engine or part. Airlines are required to carry them out, and their maintenance schedules track each one.

Who checks that airline maintenance is working?

The airline itself must run a continuing analysis and surveillance system to check that its programs are effective and to correct problems, and for older airplanes the FAA carries out its own inspection and records review.

Sources

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Facts last checked against these sources: October 18, 2026.