ARINC 600-16

It is intended that this specification be used with theapplication and customer needs in mind. To enhance the breadth ofuse, the specification is set forth in three phases defined asfollows:

a. Phase I – This phase specifies the definitions, guidances,and appraisals given in Section 1.1 for those instances in whichthe aircraft manufacturer intends to randomly mix ARINC 600 boxesand ARINC 404/404A boxes.

COMMENTARY

In some aircraft it may be that some ARINC 600 boxes will beinterspersed with ARINC 404/404A boxes on one rack while otherswill be installed in a dedicated ARINC 600 Phase I rack/cabinet.The guiding principle followed in this specification is one-waygeneration (or phase) interchangeability. ARINC 600 Phase I boxesshould meet qualification requirements and fit and performsatisfactorily when installed on a Phase 0 (ARINC 404/404A) rack.It is recognized that a portion of the ARINC 404/404A rack willhave to be made to accommodate the ARINC 600 Phase I boxes due todifferent hold-downs, different connectors. This is not to implythat cooling air will be different. Air will continue to be drawndown in 404A Racks and Phase I LRUs will have to live with thiscondition. On the other hand, an ARINC 404/404A box could not beinstalled in an ARINC 600 Phase I rack/cabinet because it may betoo large, it has front “dog houses,” a cooling system (e.g., holesin the sides of the LRU) that would upset the cooling provided inan ARINC 600 Phase I Rack/Cabinet, and for other reasons. The userof this Specification may, therefore, always install a mix of boxesin the lower numbered phase rack/cabinet and only two phases willbe mixed in one rack/cabinet.For purposes of this discussion,RINC404/404A is considered Phase 0 when considered along with ARINC600 Phase I.

b. Phase II – This phase specifies the definitions, guidances,and appraisals given in Section 1.1 for those instances where ARINC600 LRUs are of a design catering to mechanical, electrical, andenvironmental control that is substantially beyond those featuresfor Phase I. Phase II, therefore, is another step in theevolutionary development of avionic installations. It is intendedto enhance the operator’s satisfaction with avionics built to andinstalled in accordance with Phase II specifications. Thissatisfaction is meant to encompass life cycle cost, reliability,maintainability, etc. As with Phase I and ARINC 404/404A, it islikely that aircraft manufacturers will find it necessary(convenient) to sometimes mix Phase II LRUs and Phase I LRUs in thenew rack. When this is done, the installation criteria for Phase Iwill prevail. However, it will not be proper to install Phase IILRUs in ARINC 404/404A shelves since these shelves will not be ableto meet certain Phase II requirements. The standard rule is, asstated above, always install a mix of LRU phases in thelower-numbered phase shelf/cabinet and no more than two phases maybe mixed on one shelf. Put differently, a Phase N + 1 LRU can beused in (and only in) a Phase N or a Phase N+ 1 Rack/Cabinet.Similarly, a Phase N LRU can be used only in a Phase N or Phase N -1 Rack/Cabinet.

COMMENTARY

The commentary set forth in (a) above generally applies here. Itmust be clearly understood that a Phase II box has not yet beenfully defined and may not be expected to fit or survive in an ARINC404/404A rack.

c. Phase III- This phase specifies the definitions, guidances,and appraisals given in Section 1.1 for those instances where ARINC600 LRUs are of a design catering to improved mechanical,electrical, and environmental control that is substantially beyondthose features for Phase II. The criteria for mixing Phase II andPhase III LRUs include the requirement that such a mix must alwaysoccur in a Phase III Rack/Cabinet only.

COMMENTARY

The commentaries under (a) and (b) generally apply here.

NIC Phase I Design Requirements are contained in Section 3 ofthis document. Phase II and Phase III Design Requirements will beprovided as additional sections when they are developed and adoptedby AEEC.

Edition:

06

Published:

11/22/2006

Number of Pages:

286

File Size:

1 file , 3.7 MB