Narrative:

We are finding severely clogged equipment cooling air filters for the weather radar transceivers on the A320 and B757 fleets. Some of these filters are so clogged you are unable to see direct sunlight through them. These small; washable filters are located on the weather radar transceiver trays and are the last catch to clean the cooling air before it enters the computer. While a clogged filter may not cause an immediate failure of the transceiver (TR); the elevated temperatures inside this component must drastically affect its service life. The airline effect is this: weather-radar (w-r) systems are rarely deferred; refused by either dispatch or flight crew on a consistent basis. At non-maintenance stations; [this] can be a cancellation. Maintenance requirements: repairs can add hours to an aircraft refusal; especially on the B757 (B757s require a pushback from the gate and 300 ft clearances for radar operational tests).

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Original NASA ASRS Text

Title: A Line Mechanic reports finding severely clogged Equipment Cooling air filters for the Weather Radar Transceivers on A320 and B757 fleets; causing elevated temperatures inside the Transceivers.

Narrative: We are finding severely clogged Equipment Cooling air filters for the Weather Radar Transceivers on the A320 and B757 fleets. Some of these filters are so clogged you are unable to see direct sunlight through them. These small; washable filters are located on the Weather Radar Transceiver trays and are the last catch to clean the cooling air before it enters the computer. While a clogged filter may not cause an immediate failure of the Transceiver (TR); the elevated temperatures inside this component must drastically affect its service life. The airline effect is this: Weather-Radar (W-R) systems are rarely deferred; refused by either Dispatch or flight crew on a consistent basis. At non-maintenance stations; [this] can be a cancellation. Maintenance requirements: repairs can add hours to an aircraft refusal; especially on the B757 (B757s require a pushback from the gate and 300 FT clearances for radar operational tests).

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.