• Provides fault detection and analysis for the Collins Pro Line 4 and Pro Line 21 systems
• Monitors avionics and aircraft system LRUs to detect failures and assists maintenance personnel with identification of LRUs requiring replacement
• Logs fault data to permit diagnosis of intermittent faults
• Load maintenance diagnostic tables independent of application
• Provides capability to download fault information to disk
• Displays fault information in instantly recognizable English words and phrases as well as using traditional hexadecimal and binary readouts
• Integrated with an aircraft's EICAS to collect engine and airframe wear information thereby simplifying the airplane maintenance program
• Provides extensive airframe/user customized electronic checklists
• Provides test and rigging functions for supporting system LRUs
• Provides remote access of maintenance information
• Provides ACARS support for downlinking of maintenance reports
• Separately loadable Maintenance Diagnostic Tables

The Collins MDS-3110/4110 Maintenance Diagnostic System performs an integral function within Pro Line 4 and Pro Line 21 by monitoring Line Replaceable Units (LRUs) and Line Replaceable Modules (LRMs) to detect failures, identifying LRUs requiring replacement and logging fault data to permit diagnosis of intermittent faults. Along with the system's ability to provide avionics maintenance diagnostics, the MDS-3110/4110 can also display aircraft systems data, engine maintenance information and extensive airframe/user customized checklists that depend on aircraft configuration. In addition, the MDS-3110/4110 provides test and rigging functions for supporting system LRUs, remote access of maintenance information through a PC or Portable Maintenance Access Terminal (PMAT), and support for downlinking of maintenance reports via ACARS. With this level of system flexibility, the effective maintenance of the aircraft is increased along with significant cost of ownership benefits being realized.

The MDS-3110/4110 provides fault detection and analysis as well as immediate identification, recording and display of maintenance information. The system utilizes the flight deck Multifunction Displays (MFDs) as the display media for the fault information and uses a variety of formats that include an English format along with the traditional hexadecimal and binary readouts to depict diagnostic information. By incorporating instantly recognizable English words and phrases, the ability of flight crew or maintenance personnel to take appropriate action quickly and accurately is greatly enhanced, thereby increasing the utilization of the aircraft.

The system can also be integrated with an aircraft's Engine Indication and Crew Alerting System (EICAS) to store captured events, service messages, engine exceedances, engine trend snapshots, system parameters and aircraft life cycle counters. By providing a means to collect engine and airframe wear information, the MDS-3110/4110 simplifies the airplane maintenance program by giving single-point access to long-term engine trend and historical airplane data.

Reduction of paper in the flight deck in terms of checklists is yet another benefit of the MDS-3110/4110. Electronic airframe/user checklists can be stored, accessed and executed by the system. Checklists to cover normal operations and specific crew notes, as well as abnormal and emergency operations can be incorporated into the MDS-3110/4110.

To assist the maintenance personnel with troubleshooting and aircraft checkout, the MDS-3110/4110 provides the capability to initiate LRU tests and rigging procedures. The maintenance information can be accessed either through the flight deck MFDs or through a PMAT running the Remote Maintenance Access (RMA) application. To support look-ahead maintenance, the MDS-3110/4110 can transmit the maintenance information via ACARS.

The MDS-3110/4110 is comprised of two LRUs - the MDC-3110/4110 Maintenance Diagnostic Computer and the DBU-4000/4100/5000 Database Unit. A separate, loadable MDT-3110 Maintenance Diagnostic Table that is specific to an aircraft program is also provided. The MDC is packaged in the Pro Line Integrated Avionics Processing System, reducing avionics weight and size and simplifying avionics interconnect. This integration allows the MDS-3110/4110 to gain extensive access to available aircraft system diagnostic information.

The MDT-3110 provides aircraft unique diagnostic data for the MDC-3110/4110 to operate on to diagnose faults unique to the aircraft type. The MDT-3110 is a separate software part that can be field loaded into the MDC-3110/110 using the DBU-4000/4100/5000 Database Unit. Refer to the MDT-3110 Service Information Letter (SIL) 1-04 for proper MDT version information for the applicable aircraft program.

With the integrated nature of the Collins Pro Line 4 and Pro Line 21 systems, a computer is paramount in providing assistance with the maintainability of the equipment. The MDS-3110/4110 provides that assistance in the form of fault processing and overall system utility support.

Reporting LRUs can provide one or more dedicated fault words to the system for which fault equations may be generated. A typical number of fault equations created for an aircraft's MDS is 2000 (this number is dependent on the application). To further enhance the user interface, custom English text fault descriptions up to 24 ASCII characters can be provided for each LRU fault condition.

• The current fault page displays the faults currently detected by the MDS. The information available includes the name of the failed LRU, its ATA chapter number, operational status and associated fault in English text format. This page provides a concise summary of the current fault status to the flight or maintenance crew prior to departure.
• The fault history page lists the LRUs with persistent or intermittent faults and provides a text fault message, the state of its diagnostic words at the time the fault occurred and the time/date of occurrence for each fault. The system can store up to 20 LRU fault entries per flight leg, a total of 100 flight legs and display a maximum number of 500 entries. When the fault leg storage is full, the oldest stored flight leg data will be overwritten.
• For a selected fault, the advanced diagnostics page displays the current state of diagnostic information for the reporting LRUs, as well as help and troubleshooting tips. The diagnostic information can be displayed in traditional hexadecimal and binary readouts, along with English text through the data reader page. This data is provided to help determine the specific cause of a failure and is available in real-time for all reporting LRUs.
• Service messages are text fault messages that correlate to crew alert or maintenance messages and are time/date stamped when the event occurred.
• At the completion of a flight, a flight leg index display can be accessed to provide an overview of prior flights. The index shows the number of faults, service messages and exceedances that were recorded for a flight. An indication is also provided to show if engine trend data was recorded during a flight. If further data is required for a particular flight leg, a summary display shows all if information stored for the selected flight. The index and summary displays are provided to permit quick assessment of all events that occurred on a specific flight.

• A long-term history of engine exceedances is provided to help crews to determine when engine maintenance inspections are necessary.
• Engine trend data offered by the system also assists in determining when an engine should be taken out of service for inspection or repairs by comparing current data to historical data.
• System exceedances are available and report in text form the threshold for a particular parameter, the peak value reached, the duration of the exceedance and the time/date when the event occurred.

By coupling EICAS support with the maintenance diagnostic system, the flight crew and maintenance personnel are given ready access to monitor the condition of various equipment complements on the aircraft. It is this level of unprecedented integration that has proven to be extremely valuable in the area of aircraft dispatchability.