A commercial airliner typically has a service life of 20 to 30 years, though its "age" is measured more accurately by flight cycles (one takeoff and landing) and flight hours rather than calendar years. Narrow-body aircraft like the Boeing 737 often retire after about 50,000 to 60,000 cycles, while wide-body jets like the Boeing 777 are built for roughly 25 to 30 years of long-haul service. Interestingly, many passenger planes find a second life after "retirement" by being converted into freighters for companies like FedEx or UPS, where they can fly for another 10 to 15 years. With meticulous maintenance and part replacements, some specialty aircraft have flown for over 50 years; for instance, certain variants of the Boeing 737-200 are still operational in remote regions in 2026, despite being over half a century old, because their over-engineered frames remain structurally sound.