New Cessna Service Bulletin 1973 and up 337's
 

MEB09-3 titled Electrical Switches Inspection and Replacement dated May 11, 2009. Effectivity: T303, 337G-H, T337G, P337H, F337G, F337H, FT337GP, FT337HP. Purpose: to inspect switched installed in the landing light, taxi light and beacon light circuits for time in service. Switches that have been in service for 4 or more years shall be replaced and the month and year of installation shall be written on the new replacement switch. Compliance: Mandatory: shall be accomplished within the next 400 hours of operation or 12 months, whichever occurs first. NOTE: For future switch replacement intervals after compliance with this Service Bulletin, refer to the applicable airplane Service/Maintenance Manual. Revised switch replacement intervals are in development and will be issued in the next revision to the affected airplanes Service/Maintenance Manuals.

I want to interject something here, there is no such thing as a "Mandatory" service bulletin. The only things that are mandatory are AD notes and type certificate data sheet limitations. If I were to arbitrarily start replacing switches, it would be master and alternator switches as they cause many problems associated with age and high resistance.

Why the SB about switches of all things? Has there been an accident because of switches? I'm not sure I understand Cessna's motives...a 4 year switch? What about all the 30 & 40 year old switches on other Cessna switches?

Probably just that Cessna's running a little short of money. There is a sort of depression on, you know... And I haven't heard of Cessna getting any "bailout" money.