This document provides guidance to users of ACS for the development of methods to control and manage ACS. Ideals contained within this document were developed from past experience and future expectations based on the business situations and maintenance actions of contributing aircraft manufacturers, airlines, Original Equipment Manufacturers (OEM), vendors, and software suppliers.

Airlines today find it cumbersome to match multiple software loading situations with multiple aircraft loading configurations. As aircraft and their components become more reliant upon software to operate, it is imperative that actions must be taken to maintain control and management of aircraft software. Different OEM installations, multiple vendor/supplier interfacing units, and varying operator requirements for data upload and retrieval have proven to be difficult integrations of the in-field software control. In the past, these short comings have caused discomposing situations. It is the clear intention of this document to provide a means to discourage such situations from being repeated. While this document is intended to provide guidance regarding methods of controlling and managing aircraft software configuration, it is recognized that many airlines have implemented different methods, reflecting their specific fleet composition and diverse infrastructure. The intention of this document is to offer guidance on how software may be managed and controlled.

Although the need for software validation after loading ACS is discussed in this document, the detailed procedures are not. Placing exacting procedures in this document will hinder ingenuity and business related decisions to further the industry. Certain subjects were specifically excluded from this document due to possible conflict or confusion between other standards. These aspects are described in related documents identified in Section 1.9. Figure 1-1 describes the overall ACS environment and shows the relationship of applicable documents.

Purpose and Goal

The purpose of this document is to provide guidance for the in-service management of Loadable Airborne Software. The types of Airborne Software are defined in Chapter 2. This document is intended to be broad and apply to all Aircraft Controlled Software (ACS). The key features of aircraft controlled software are as follows:

a. Usually capable of software load on-aircraft. Also covers hardware controlled software to some extent.

b. Part number is electronically verifiable on-aircraft.

c. Does not change target hardware part number.

d. The software has its own unique identification number.

e. The software part may be a type-certified aircraft part.

f. The software may be an application.

g. The software may be a database.

h. The software may be a document or list.