How to Understand BizAv Maintenance Diagnostics Systems

On-board maintenance diagnostics systems were introduced several decades ago with the extended use of digital computers connected to a larger number of sensors to monitor and control aircraft systems. How have they evolved today?

Aircraft maintenance diagnostics systems began with devices, such as laptops, that could be connected to aircraft computers to retrieve fault codes for each specific system, but in more recent times the technology has developed to enable improved planning of maintenance and more data integration.

Maintenance Diagnostics Systems on Business Aircraft

Today, on-board diagnostics systems are common on business aircraft, particularly for the flight deck, cabin electronics, engines, and auxiliary power units. “While these systems have evolved over time, they are still equipped in older models,” Glen Howard, Technical Information Services Director at Gulfstream, says.

“For example, the Gulfstream GV’s maintenance data acquisition unit monitored certain parameters and reported back, with several operational checks tied in.

“Beginning with the Gulfstream G450 and G550, the central maintenance computer provided diagnostics, troubleshooting and return-to-service capability. Now, Gulfstream aircraft are equipped with state-of-the-art, full health and trend monitoring systems.”

In the earlier part of the millennium, the EASy avionics suite was introduced on all production Dassault Falcon aircraft, with a Centralized Maintenance Computer (CMC) allowing consolidation of maintenance diagnostics at the aircraft level with information from all systems.

The CMC also records data files allowing more in-depth troubleshooting when necessary.

“In later years, FalconBroadcast was offered on EASy aircraft, providing the operator on the ground with real-time, in-flight notification of failures, and therefore real-time anticipation of the spares, tools and technicians required to return the aircraft to service,” explains Jean Kayanakis, Dassault Senior Vice President of Worldwide Falcon Customer Service & Service Centre.

All in-production Cessna Citation business jets, meanwhile, incorporate on-board maintenance and diagnostic systems that can transmit data while on the ground or flying.

“In addition, new turboprop models including the Cessna Denali and SkyCourier will incorporate similar on-board maintenance and diagnostics solutions, says Brian Adams, Vice President of Aftermarket Innovation at Textron Aviation.

Diagnostics Solutions for Older Aircraft?

When it comes to older aircraft, however, there is a reliance on built-in-test (BIT) or component/system supplier-provided troubleshooting software programs, Adams says.

“We recently launched an analytics project that will leverage data from our entire fleet so we can anticipate and react to the needs of the fleet long-term.

“The aircraft systems, and maintenance and diagnostic systems, require integration during initial aircraft design to be most effective,” he argues. “Therefore, there are currently no maintenance and diagnostics retrofit options for older in-service aircraft.”

Nevertheless, Howard points out that there is increasing appreciation and demand for diagnostic capability. 

“Although a complete nose-to-tail solution is not necessarily practical for an older aircraft,” he says, “elements of diagnostics are included with new systems as the aircraft is updated, which enables operators to reap the benefits.”

For older aircraft that do not have on-board maintenance diagnostics capacity, Dassault offers an on-ground maintenance diagnostics tool that it refers to as the Computer Aided Troubleshooting System (CATS).

“We are also developing aftermarket solutions to modernize cockpits, cabin in-flight entertainment (IFE) or to install Satcom systems. These new generation solutions have integrated diagnostics features”, reveals Kayanakis.

Safety and Efficiency of Maintenance Diagnostics

Business aircraft safety relies on systems design, flight manual procedures to cope with failures, and scheduled maintenance.

“Maintenance diagnostics systems improve the efficiency to achieve these safety requirements, providing a better in-depth knowledge and monitoring of the health of each system”, says Kayanakis. “For example, it allows [owners/operators] to decrease the amount of scheduled maintenance that would otherwise be required to achieve this monitoring”.

And health and trend monitoring and diagnostics systems provide benefits in terms of safety and efficiency, as well as improved reliability and aircraft availability, thereby enabling aircraft operators to conduct proactive maintenance.

“The introduction of greater capabilities and performance in aircraft systems has resulted in many more sensors which are able to provide a wider variety of information about the health of the aircraft and its systems,” Howard notes.

In case of failure, these systems directly point to the root cause in about 95% of the cases, avoiding the need for additional tests on aircraft, helping reduce the time for technicians to fix the problem.

“Thanks to these systems, together with the equipment manufacturers, we can also collect and analyze data from a large part of the in-service fleet, using the comprehensive feedback for improving systems reliability, as well as the computer diagnostics algorithms or fault isolation procedures”, Kayanakis says.

“Maintenance diagnostics offer the potential for increased safety by supplementing detailed analysis of component wear and in-service anomalies, leading to better-informed maintenance processes and procedures,” Howard adds, “and that results in fewer failures and safer operations.”

Textron Aviation recently announced LinxUs FDM which allows operators to participate in Flight Data Monitoring (FDM)/Flight Operations Quality Assurance (FOQA) services from authorized providers using data from the on-board maintenance and diagnostic systems.

“The on-board maintenance and diagnostics system identifies both the root cause and corrective action of an issue the first time it happens”, says Adams. “The system makes the discovery portion of service quicker while also identifying trends. “LinxUs provides the customer maintenance data portal with fast fault notifications and expedites unexpected maintenance by isolating important details,” he adds.

The Future of Maintenance Tracking and Diagnostics

Looking to the future, the growing variety of available aircraft system data will enable analysis of fleet data to establish more accurate failure rates of components and, potentially, extend component replacement intervals, says Howard.

“Additionally, the trend toward integrating electronic components has reduced part counts and improved overall reliability, while enabling statistical maintenance data which can help quickly identify the most likely root cause and recommended action”, he says.

“For example, if similar failures have occurred on other aircraft in the fleet, a recommendation can be made from the OEM to help identify the most likely cause. This enables the maintenance technician to more quickly isolate the relevant issue rather than spend time executing a lengthier troubleshooting procedure.

“The trend for certain events can trigger notifications to the maintenance team, which provides advance warning and enables maintenance actions or component replacement to be scheduled at a convenient time, rather than waiting for a potential failure to occur,” Howard adds.

As more systems participate in on-board maintenance and diagnostics solutions this will allow maintenance technicians to eliminate most ancillary troubleshooting tools. 

“With more digital systems participating in on-board tools, the ability to identify both root cause and corrective action at the first occurrence has greatly improved,” Adams notes.

“The robust on-board tools coupled with the ability to transmit relevant data airborne allows us to prepare aircraft maintenance actions before the airplane lands,” he adds. “We continue to upgrade and add new customer-facing solutions through LinxUs, our customer data portal.”

With its Falcon 6X, Dassault is introducing a new maintenance diagnostics system branded FalconScan.

“This system features new capacities that include recording of about 100,000 aircraft parameters, smart diagnostics performed by our patented algorithms – providing unique capacity to isolate the faulty equipment – and is ready for the next-generation health and trend monitoring program development that include prognostic algorithm integration and ‘big data’ advanced services,” concludes Kayanakis.

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