Type certificate A4EA
Held today by Helio Aircraft LLC, earlier by Helio Enterprises, INC., Helio Enterprises\Inc.. It covers 2 models. Last revised August 21, 2015 (revision 16). 62 approved modifications build on it.
Models under this certificate 2
HST-550A (USAF AU-24A), HST-550
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 0 · newest first
None in the current files.
Approved modifications 62 · 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/A4EA.json.