Commercial jets age on pressurization cycles and flight hours, and Boeing fleet planners monitor both. In frontline service, a Boeing 737 typically gives around 20 years before replacement starts to make financial sense. Wide-bodies such as the 747, 777, and 787 often remain in service closer to 25 years. Those ranges are planning tools, however not expiration dates.
Across the last two decades, the average global jet age has sat at around 10 to 12 years, as fleets renew inventory even as individual aircraft can feasibly run safely far longer under their inspection programs. The FAA's Widespread Fatigue Damage rule (2010) requires every transport model to publish a Limit of Validity — a manufacturer-set cap that tells operators how long the official inspection program is valid, measured in either cycles or hours. Duty cycle simply means how an aircraft is used, as many short flights add lots of pressurizations and landings. Meanwhile, long flights add hours but result in fewer pressurizations.
Teams weigh how the plane is used, how often it leaves without issues, and what maintenance costs are expected before approving a major service event. Regulators also shape that timeline, and the service-life window of an aircraft remains open only if maintenance stays on a strictly managed schedule.
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Boeing's maintenance planning assumes long service when the schedule is kept and inspections are done on time. Heavy checks — also referred to as D checks — involve a top-to-bottom inspection that opens up the airframe for a deep look at fatigue or corrosion, then repair what those inspections uncover. Depending on type and usage, a heavy check typically lands every 6 to 12 years and can consume 30,000 to 50,000 labor hours.
Inspections use non-destructive testing (checking for cracks without damaging parts) such as dye penetrant, ultrasound, and laser measurement. The maintenance program itself is the required checklist set by the manufacturer and regulators. When safety issues arise, regulators issue Airworthiness Directives and manufacturers publish Service Bulletins, telling operators what additional work to perform. Stress can vary by environment — hot and humid conditions invite corrosion, cold or salty routes punish a plane's exterior, while dust and heat stress engines.
Monitoring these factors is critical. In 1988, Aloha Airlines Flight 243 (737-200) experienced an explosive decompression event that ripped the roof off the aircraft. The investigators traced the problem to widespread fatigue cracking in a high-cycle fuselage crown panel. Composite-rich designs such as the 787 change where fatigue develops, but they still follow the same scheduled inspection framework.
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Age is a factor in retirements, but money and mission often carry more weight. Many carriers refresh narrow-body fleets in the 10- to 15-year window, while others run aircraft longer depending on lease terms, performance, and network needs. Exits are typically aligned with heavy checks and the arrival of new deliveries.
Replacement slots can be tight, which keeps older Boeing aircraft flying as long as records are clean and inspections continue to pass. In September 2025, the FAA let Boeing resume limited self-certification on alternating weeks for the 737 MAX and 787, with the agency overseeing the other weeks. That cadence can slow or bunch deliveries and, in turn, keep older jets in service longer.
Most retired aircraft end up in deserts set up for preservation. AMARG in Tucson spans about 2,600 acres and stores thousands of aircraft. Low humidity and alkaline soil limit corrosion and allow heavy airframes to park on hardened ground without building concrete parking surfaces. Some aircraft are preserved for a return to service when demand and condition align. Others are dismantled so engines, avionics, and high-value components can be reused, with remaining materials recycled where practical.
After retirement, most airliners are parted out, resold, or find second lives. End-of-life decisions are framed by fatigue-damage policy and each model's published life limits. In practice, Boeing passenger jets bow out when the economics turn, even if the structure remains sound.
