Hobbies And Interests
Engine Life Specifications
All engines, in any application, have a limited life span. Parts wear out due to constant normal stresses, and eventually these parts fail. When the parts fail, the engine fails. The FAA is keenly aware of this, and has mandated specifications for time between overhauls, or TBO, for aircraft engines. In order for an engine to be deemed airworthy, its manufacturer has to develop management activities for engine life and submit requirements to the FAA. Understanding TBOs can get confusing, since it is not only based upon hours of running time, but based upon years of service as well. Aviation Maintenance Magazine states that the TBO is based upon manufacturer's determinations of how long their engines can last between TBO services. A logbook must be kept of an engine's running time so the overhaul can take place before the allotted hours run out.
Internal Component Specifications
In business, a popular saying is "time is money." For example, a Lycoming O-235-C1 engine has a 2010 manufacturer's suggested price of $36,342. On the surface, this is an exorbitant price for a simple piston-powered engine. Peering below the surface, however, reveals a great deal of work is invested into aircraft engines. For example, all engine bolts, no matter how small, are either X-rayed or ultrasonically tested to ensure no internal flaws or cracks are present. Because an aircraft engine is held to strict life-or-death standards, by default all internal components are held to tight specifications.
Certified Engines
In order for an engine to be deemed airworthy by the FAA, it must be certified. This is not an easy process. The specifications for certification are extensive, and the process may take years. For this reason, many engines are sold as "non-certified." This means that even though these engines are suitable for aircraft, the FAA has not yet reviewed them, or the engines are in the process of being reviewed.