Hall loves the panel, and feels confident in the redundancy. “The chances of a complete electrical failure are small. The standby alternator manages itself.” if an STCed alternative is installed and it meets the applicable regulations. Alas, Hall couldn’t find a backup alternator that was STCed for the M20J. Adams says the easiest road is an STCed system. “In these cases, it doesn’t matter what the type certificate says. Look for an STC that will get it done for you.” FINDING HELP. Knowing the removal wasn’t going to be easy, Hall set about trying to find some help. He reached out to the Mooney factory; the folks at B&C Specialty Products, which makes the backup alternator; Weber Aircraft Distributors; and his contacts at the local FSDO. When Hall learned that installing a B&C alternator THE TIGHT SPACE inside a Mooney cowling makes projects like adding a second alternator more complicated. Hall’s Lycoming IO-360 didn’t have a second pad for the additional alternator, so he removed the vacuum pump, and the shop relocated the then-ill-fitting tachometer cable (upper left). 72 | AOPA PILOT May 2013 PILOT January 2012