| Definitions |
| Certified
Engine |
In the most
basic terms, a certified engine is a “data plate”.
During the life of a certified aircraft engine, its original
identity becomes more and more obscure as components are
replaced and overhaul is performed. There is no regulatory
requirement to keep all or any of the original parts together,
so at overhaul, the overhaul process may result in an engine
in which none of the original parts are attached to the
data plate. Maintenance and overhaul is a mix and match
process in which OEM instructions must be followed but all
parts are interchangeable with non-original parts so long
as they meet the form, fit and function requirements of
the type design, they are FAA approved and they are airworthy. |
| Data Plate |
A stainless steel plate that
is affixed to an aircraft engine by the engine manufacturer
when the engine leaves the factory. Certified and non-certified
engines may have data plates and the certification status
will be noted on the data plate. The data plate is usually
affixed to the crankcase or the oil sump and is removable.
The data plate can be removed from one engine and put on
another engine so long as the configuration of the engine
meets the design requirements of the data plate. The information
stamped on a certified engine data plate can be modified
to reflect changes made to the underlying engine when approved
by the administrator. |
| Non-aircraft Engine
Conversion |
Usually an
automotive engine that has a reduction drive grafted on
to the front end of the engine. |
| OEM |
Original Equipment Manufacturer. |
| Scratch
Built Engine |
A traditional
type aircraft engine that starts with the acquisition of
a core. The core is acquired through local sources, auctions,
salvage companies or ads placed in aviation magazines and
is usually purchased on a caveat emptor basis. The core
is disassembled, cleaned and inspected and parts are replaced
by choice or as necessary. The parts can be new or used.
The resulting engine can be certified or non-certified. |
| STC |
Supplemental Type Certificate |
| TBO |
Time Between
Overhaul. This value (operating hours) is established by
the OEM as part of the engine certification process. Commercial
use of a certified engine requires that the TBO be observed,
however, Part 91 (recreational use) does not require that
the engine be overhauled at any specific time but rather,
on condition. |
| Traditional Kit Engine |
A non-certificated traditional
type aircraft engine built from new certified (FAA-PMA)
parts that are designed and manufactured as direct replacement
parts for use in the certified engine of similar design.
The engine is assembled and tested in accordance with practices
and procedures published for the certified version of the
engine. |
| Traditional
Non-certified Aircraft Engine |
An engine that
is purposely designed and built to be installed in an airplane
and power a propeller. The engine may or may not have a
reduction drive. Certification of the engine was never contemplated
by the designer and there is no certified engine of similar
design. |
| Type |
As used with respect to aircraft
engines means those engines which are similar in design. |