My A&P/AI, who does owner assisted annuals for me and has saved me literally thousands of $$$, is reluctant to install the USB charger I bought. (See above post). He thinks it is a major modification and needs an STC. For those of you who have installed a new USB charging device, what did it take to have someone install and sign it off?
Cheers, Elliot

With a mile of highway, you can go one mile. With a mile of runway, you can go just about anywhere.
[Linked Image from visitedstatesmap.com]