On aircraft the electronics bay contains multiple systems, e.g. for the A320:

photo corresponding to the above diagram
A320, photo by B-2230, source: JetPhotos

How is the electronic equipment locked (it seems there are two mobile screws) and how are the wires connected? Details will be appreciated: standards, diagrams, images...

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    $\begingroup$ This company page (not affiliated) seems to provide better images of the various trays and fasteners: avionicshardwareandmounts.com $\endgroup$ Dec 1, 2017 at 14:47
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    $\begingroup$ And this company's product catalog seems to provide some illustrations of the hold down mechanisms: arconic.com/fastening_systems_and_rings/aerospace/catalog/pdf/… $\endgroup$ Dec 1, 2017 at 14:51
  • $\begingroup$ @selectstriker2: Very good finds, that's more than what I was looking for. $\endgroup$
    – mins
    Dec 1, 2017 at 14:53
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    $\begingroup$ @selectstriker2 I totally think you should add that to your answer, it completes it quite nicely $\endgroup$
    – Federico
    Dec 1, 2017 at 15:25

1 Answer 1


The LRUs are attached to trays which house the electrical connectors and the cabling behind them: enter image description here source

The hold down mechanisms vary in design, but it appears they generally attach the LRU to the tray at the front, the back likely being held in by the electrical connectors at the back.

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    $\begingroup$ The LRUs slide into the trays and are electrically mated at the rear. There are small hooks on the bottom front of the LRUs. The hold down is a screw collar on the bottom front of the tray that swings up and is screwed down over the hook. Additionally, the trays support forced-air cooling of the LRUs. Air is forced up through the LRUs (the plastic on the bottom of the trays in the pic is a flow restrictor.) It's all spelled out in ARINC Characteristic 600. $\endgroup$
    – Gerry
    Dec 1, 2017 at 17:00

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