Panel Switches

Cliff Daugherty's installation of SK-156

Service Kit #156, the replacement of the instrument panel rocker switches with toggle switches, was primarily cosmetic as only two switches had failed in the past 33 years. The paperwork is avaiable from Fletchair in Houston, Texas. However, the new rocker switches were slightly different than the original and didn’t fit as well in the holes. So the sub panel cut out as shown to make room for the toggle switches.

Note the connecting structure between the two holes - it is important to not make the cutout too wide as it compromises the strength of the sub panel.

The aluminum plate was fabricated, painted, and engraved instead of using the placards suggested in the SK. As an alternative, a plastic placard to match the aluminum piece could also be used and simply glued to the metal.

Mark Matthews created the aluminum plate using design software from [Front Panel Express], who also manufactures the plate for you. Cost was less that $40 delivered, and about a week turnaround time.

SK #156 first came about from a request from the UK CAA to address the problems of overheating and smoke in the copit from the cheap Carling rocker switches. In Europe there is an Annual AD to inspect these switches and spade connectors for signs of overheating. At one stage it looked like SK156 was to become mandatory, but common sense prevailed.