Glossary
Engine Time
Hours an aircraft engine has accumulated since new manufacture or its most recent overhaul.
Definition
Engine time describes how many hours an aircraft engine has operated. The two most commonly referenced figures are Time Since New (TSN) and Time Since Overhaul (TSOH or TSOh). Most piston and turboprop engines also have a manufacturer-recommended Time Between Overhauls (TBO) — the interval at which an overhaul is recommended or required, depending on the operating rule.
Why it matters in a transaction
Engine time directly affects remaining useful life estimates, the likelihood of near-term overhaul costs, and resale value. An engine approaching TBO may require a major overhaul costing tens of thousands of dollars, so knowing engine time is essential for budgeting. Some engines are also run on condition rather than a fixed TBO interval, which changes the calculus.
What TailExchange can help you see
TailExchange displays engine time when provided by the seller. Listings that include both TSN and TSOH figures give you more to work with when comparing aircraft.
What TailExchange cannot verify or replace
TailExchange cannot verify engine time, confirm whether an overhaul was factory-performed or field-overhauled, or assess engine condition. Engine logbook review and a compressions test or borescope during a prebuy inspection are the appropriate ways to evaluate this.
Related
Airframe Time
Total hours the aircraft structure has been in flight since manufacture or major rebuild.
Prebuy Inspection
An independent mechanical inspection performed by an A&P mechanic before an aircraft purchase.
Annual Inspection
An FAA-required annual airworthiness inspection that must be completed for an aircraft to remain legally airworthy.
Prebuy Inspection vs. Annual Inspection
What is the difference between a prebuy inspection and an annual inspection?
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