Standard chassis frames provide an excellent method of housing rapidly developed products, as well as providing a low cost advantage since they are manufactured in volume. These frames are used over and over to provide the level of support required for vendors and customers who can leverage them appropriately.
For more difficult applications (eg where installation may be as part of an airborne system mounted in either a small or large aircraft) there may be other considerations. The dominant features for these installations are that subsystems can be removed and inserted from the front of the chassis in a few seconds just like the familiar “cassette”. Connectors align accurately and slide in without human touch. There are no plugs that have to be removed from the rear or reason for any special access. The “cassette” approach allows an operator to conduct replacement maintenance during a mission without otherwise delaying it. The time to re-insert a new cassette allows him to be up and running again after unit replacement within a very short time. System recalibration can occur quickly with the newly replaced hardware, but there is no rear access required at any time during this replacement. Precision slides do it all!