AMC E 20  Engine Configuration and Interfaces

ED Decision 2007/015/R

(1)     The components and equipment listed in the Engine type design (see CS-E 20(a)) should include those items necessary for the satisfactory functioning and control of the Engine.

(2)     It is not necessary to include any items required to provide non mechanical inputs to the Engine if the characteristics of these inputs (e.g. voltage, current, timing, fuel, air, etc) can be clearly specified.

(3)     The components or equipment identified under CS-E 20(c) constitute interfaces for the purposes of CS-E 20(d). The effect of these components or equipment on the Engine should be considered during the Engine certification, in normal and Failure cases (see CS-E 80). The Engine instructions for installation required under CS-E 20(d) should clearly specify the need for such components or equipment to comply with CS-E 80(c).

(4)     The applicant should give the aircraft manufacturer the information on the assumptions which were made during the Engine certification and which need to be taken into account when designing the installation (see CS-E 30). The applicant should ensure, when appropriate in co-ordination with the aircraft manufacturer, that Engine design considerations which might be imposed by the assumed installation certification specifications are taken into account. For example, all necessary provision should be made in the Engine for the fitment and operation of at least the mandatory items of equipment prescribed by the use of the word ‘should’ in the assumed applicable aircraft specifications.

(5)     The Engine instructions for installation should include or make reference to installation interface descriptions, limitations, and specifications for the Engine Control System. For example, the Electronic Engine Control System (EECS) power specifications and quality, including interrupt limitations, should be clearly defined for the installer. Another example is that the impedance and buffering limitations for the signals provided by the EECS for display and instrumentation, or signals used by the EECS, such as air data information, should be specified.

(6)     The trend toward system integration may lead to EECS that:

—          Have other control functions integrated within the Engine Control System, such as an integrated Engine and Propeller Control System or,

—          Depend on aircraft resources.

Examples of these aircraft supplied resources include recording of rotorcraft One Engine Inoperative data and aircraft central computers that perform some or all of the Engine control functions.

The applicant is responsible for specifying the specifications for the EECS for these aircraft supplied resources in the Engine instructions for installation and substantiating the adequacy of those specifications.

(7)     The Engine instructions for installation should include a description of all operational modes of the Engine Control System and its functional interface with the aircraft systems including Back-up or Alternate Modes whether dispatchable or not, and including the Propeller when applicable.

[Amdt. No.: E/1]