Monitoring debris in aircraft fluid systems can warn of potential problems with critical components, highlighting typical or accelerated wear conditions prior to failure.

This results in:

• reduced maintenance delays
• reduced in-flight shutdowns

While traditional analysis methods are effective, they are time-consuming and have limitations on the type, size, and nature of contamination detected. The Pall Dirt Alert^® Filter Element contains a removable layer of porous material that has been incorporated in the pleats of a traditional filter element. This layer can be easily pulled out and examined for visible signs of wear debris retained on the surface. The layer provides an indication of all fluid system particulate contaminants, whether metallic or non-metallic. The Dirt Alert filter can be designed as a "green run" element to replace the original BOM filter during testing or as a direct BOM replacement for use during normal operation.

Built-in manufacturing debris, operating system component wear, as well as ingested environmental contaminants, all introduce harmful impurities into fluid systems. These particulates reduce performance, system reliability and can potentially cause catastrophic failure. The control of these contaminants with "green run" and bill of material (BOM) filtration is fundamental to proper system operation. However, the identification of these contaminants can also provide valuable information on potential system problems.

The Dirt Alert ^® Filter Element helps prevent system failure by alerting maintenance crews to impending problems inside the system. After "green runs" or during normal operation, the maintenance crew can easily inspect the diagnostic layer and determine the types of debris being introduced into the system. Should the debris indicate incipient failure, perhaps due to a defective or incorrectly installed part, The Dirt Alert filter provides advanced warning. This allows repairs to be initiated before significant damage or failure.

Many OEM's specify Dirt Alert filter elements for use during "green runs" to help identify systems in need of additional work before shipment to the customer. In many cases the diagnostic layer is used as overhaul and "green run" validation. Numerous end-users replace their BOM filters with Dirt Alert filters for system condition monitoring, providing an added measure of safety and reduced maintenance delays.

Airline systems engineers and mechanics know that debris captured by a filter element can indicate potential problems in their fluid systems prior to incipient failure of critical components. Maintenance manuals instruct mechanics in "thumbing" of filter element pleats and even in dissecting the filters to examine debris collected by the element. These procedures are costly, difficult to accomplish, and may not be effective.

The Pall Dirt Alert Filter Element is designed to permit easy viewing of captured debris. The element is directly interchangeable with the current filter and incorporates a full-flow (pull-out) diagnostic layer of porous medium. This pull-out layer can be easily removed for on-site examination of both magnetic and non-magnetic collected debris.

Air Canada was interested in differentiating characteristic wear debris from normal debris, including coke/carbon. Pall presented Air Canada with the Dirt Alert Filter Element. The filter was evaluated in the test cell and later flight tested. Air Canada approved the Dirt Alert Filter Element and has been using it since 1989. With the Dirt Alert Filter Element, Air Canada can easily distinguish unusual wear debris and contamination from normal/background debris. It has been used on more than 190 JT8D engines and accumulated over 1.8 million flight hours. During that time, the Dirt Alert filter has helped mechanics identify a number of potential failures, thereby preventing in-flight shutdowns of those engines.