In 2003, mechanical and maintenance were the major cause of 15% of all GA accidents, and 7.5% of fatal accidents

Typically, one mistake or failure—a precipitating event—leads to another in a cascading series of malfunctions and mistakes, culminatiing in an accident. This is called the accident chain.

By any calculation, the average pilot could fly many, many lifetimes without having an accident of any sort, let alone a much more rare fatal mishap.

In 2003, electrical/ignition failures accounted for 3% of all accidents, and 0% of fatal accidents.

2004 Nall Report

  
 

CIRRUS Monthly Proficiency Program
3 part series on IFR operations
August – Part 1: Electrical Systems


  • Isolation Diode
    The isolation diode connects the essential distribution bus and the main bus in the MCU. The diode prevents ALT 2 and BAT 2 from supplying power to the main distribution bus. In the event of an ALT 2 failure, the diode allows ALT 1 to supply power to the essential distribution bus.

Why a diode and not a cross-tie switch?
The diode isolates a failure to one bus. At times, equipment can cause an alternator to fail. A cross-tie switch would potentially allow the same equipment to damage the entire electrical system.

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