Aeronautical Design Standard 79-B Handbook For Condition Based Maintenance On Us Army Aircraft

The purpose of this paper is to provide the widest dissemination of the Army's efforts to further Condition Based Maintenance (CBM) which is documented in Aeronautical Design Standard 79-B Handbook (ADS-79B HDBK). The Army has spent over ten years and hundreds of millions of dollars to refine a practical approach to implementing CBM and is pioneering end-user benefits from CBM (with about half the fleet equipped with monitoring systems). The Handbook outlines the engineering approach for obtaining maintenance credits utilizing four proven methodologies. These four methodologies are: Embedded Diagnostics (vibration monitoring), Fatigue Damage Monitoring, Regime Recognition, and Fatigue Damage Remediation. ADS-79B HDBK describes the Army's various CBM systems and defines the overall engineering guidance necessary to achieve the CBM goals and objectives for Army Aviation rotary wing helicopters. Future versions of the Handbook will provide guidance for Unmanned Aerial Systems (UAS) as well. The ADS-79 HDBK was first published in January 2009 and is updated on an annual basis. Feedback on the contents of the Handbook are solicited and highly encouraged from all facets of the aviation community during the annual update cycle. ADS-79-B HDBK provides guidance and standards to be used in development of the data, software and equipment to support Condition Based Maintenance (CBM) for systems, subsystems and components of US Army rotary wing helicopters. This guidance can be readily adapted by other governmental agencies as well as commercial implementations. The purpose of Condition Based Maintenance is to take maintenance action on equipment where there is evidence of need. Maintenance guidance is based on the condition or status of the equipment instead of specified calendar or time based limits such as Maximum Operating Time (MOT) while preserving the system baseline risk. The key to implementing CBM is to 'right size' CBM for the targeted platform. This is achieved by defining what is practical to implement vs. attempting to implement condition based maintenance on all possible equipment. The Design Handbook describes the elements that enable the issuance of CBM Credits, or modified inspection and removal criteria of components based on measured condition and actual usage utilizing systems engineering methods proven by Army Aviation Engineering Directorate's team of highly skilled engineers. CBM is a set of maintenance processes and capabilities derived primarily from the real time assessment of system condition which are obtained from embedded sensors and/or external test and measurements using portable equipment. This paper will examine the general guidance and associate required reliability guidance (validation) for Embedded Diagnostics, Fatigue Damage Monitoring, Regime Recognition, and Fatigue Damage Remediation. The paper will further examine specific guidance in areas such as State Detection, Data Acquisition, Health Assessment, Prognostics Assessment, Modifying Maintenance Intervals, Seeded Fault Testing, and the creation of the CBM Management Plan.