Type certificate E-304
Held today by Lycoming Engines, earlier by Textron Lycoming, Avco Corporation. It covers 21 models; about 113 aircraft on the U.S. register are built to the designs it names. Last revised November 4, 2010 (revision 8). 13 FAA orders name its designs, and 22 approved modifications build on it.
Models under this certificate 21
VO-540-B2G, VO-540-B2A, VO-540-B2D, VO-540-B1B3, VO-540-B1D, VO-540-B1C, VO-540-B1A, VO-540-A2A, VO-540-B1B, VO-540-B2E, VO-540-B1E, VO-540-B1H3, VO-540-C1A, VO-540-B2C, VO-540-B1F, VO-540-C2A (O-540-9), VO-540-C2C, VO-540-C1C3, VO-540-A1A, VO-540-C2B, VO-540-C1B
Engine series
The data sheet on the FAA's site: the approved engines and propellers, weights, speeds and limits for each model.
FAA orders on these designs 13 · newest first
Approved modifications 22 · companies holding the most
Source: FAA type certificate data sheets (Dynamic Regulatory System); register counts from the FAA register of October 5, 2026. Connections as data: /graph/certificate/E-304.json.