For LRUs with cooling requirements, tray assemblies can support convection air fl ow, aircraft
forced air cooling, and forced air cooling requiring a fan:
An LRU without external forced air cooling may require a tray shell with an oval cutout to
optimize air fl ow to cool the LRU through normal convection.
Trays are designed to accommodate forced air cooling from the aircraft or a tray mounted fan.
Metering Plates and Seals:
Air inlet holes in the metering plate allow for air fl ow regulation. Metering plate seals and
baffl e plugs (plug bumpers) are supplied with each tray assembly for insertion by the customer
to direct air fl ow as required. For assemblies requiring a fan, we also provide an
open metering plate or seal retainer for maximum air fl ow.
Fan Assemblies and Filters:
Trays are designed with options for rear, side or bottom mounted fans and meet ARINC
600 Level (1) or Level (2) cooling requirements.