Maintainability | In-service Maintainability module

Introduction

The objective of the MSG-3 is to present means for developing the scheduled maintenance tasks and intervals which need to be acceptable to the authorities (1). MSG-3 is of great utility for determining scheduled maintenance requirements during the life of the aircraft. MSG-3 analyses do not include the non-scheduled or non-routine maintenance.

MSG-3 is used to determine the initial scheduled maintenance requirements based on the certificated operating capabilities. However, MSG-3 analyses can be modified or added/deleted throughout the lifespan of the aircraft, due to design modifications or safety discovers.

There are mainly four types of scheduled maintenance according to the MSG-3 document:

• Aircraft Systems/Powerplant Analyses: The MSIs are identified and the analyses are usually grouped by ATA chapters.

• Structural Analyses: All the SSIs are identified and the scheduled maintenance tasks are developed. Mandatory replacement times for the SSIs are included in the Airworthiness Limitations (chapter 4 of the AMM).

• Zonal Analyses: It requires an analysis of each zone on the aircraft. These analyses enable appropriate attention to electrical wiring, plumbing or ducting installations.

• L/HIRF Analyses: These analyses try to reduce the possibility of a single failure cause (e.g. lighting strike) or a common failure cause.

Content

The content of the FRACAS module is:

• MSG-3 MSI Analysis
  • MSI (Maintenance Significant Items)
  • Failures
  • Questions
  • Answers
  • SCM Tasks
  • Report & Export
• MSG-3 Zonal Analysis Procedure
  • Zone
  • Zonal analysis
  • Zonal tasks
• Zonal Safety Assesment
  • Zones
  • Requirements
  • Findings
• Maintainability settings
  • Report settings
  • MSI Analysis Task intervals
  • Rating tables intervals