How To Survive an STCWritten by Norm Ellis
This portion of the article about the application process for Supplemental Type Certificates was generated by listening to aircraft owners, A&Ps and A&P/IAs across the United States complaining about Flight Standards District Offices (FSDO) no longer approving Field Approvals Form 337 for aircraft.
I don’t know what brought about the modification to FAA Order 8300.10, Volume 2, Chapter 1, Change 15, which listed unacceptable alterations, but after hearing complaints, the FAA was prompted to create Change 16 stating what can be altered under FAA given guidelines.
Form 337 serves two main purposes. One provides aircraft owner(s) and operator(s) with a record of major repairs or alterations made to only one aircraft, an airframe, powerplant, propeller, appliance, or spare parts (indicating the details and approvals). The other provides the FAA with a copy of the form for inclusion in the aircraft records at the FAA Aircraft Registration Branch in Oklahoma City. Form 337 is, basically, a history of the aircraft.