>>1b. John Cooper, a working A&P/AI, agreed that the skull cap spinner is not permitted without an approved form 337 for that aircraft but he didn't cite his documentary source.<<
Just to keep me honest, I am not an IA, although I am an A&P. I did cite a documentary source, Part 45 appendix A, definition of a major alteration. However, it is the lack of documentation permitting the skull cap that I feel is most compelling. In addition, the aircraft specification or TCDS lists items where there is a choice, like the engine and prop, but is mute on items where there is no choice, like wings, cowls, and, IMHO, spinners. John Cooper Skyport Services www.skyportservices.net
