SA2921WE
Reduce size of cockpit openings, install rounded windshields, flush rivet and increase fuselage skin gages, install internal top longerons, remove external top longerons and install internal aileron balance weight. Held by Helicorp INC., which holds 3 approved modifications in all. Last revised April 30, 2008. System: flight controls.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Ryan Aeronautical Company
- Models
- ST-3KR
- Type certificate
- A-749
- On this site
- Ryan Aeronautical ST3 116 registered
- The FAA's record
- On the FAA's site
What an approved modification is
A supplemental type certificate is the FAA's approval of a change to a certified design: a new engine or propeller, avionics, an autopilot, floats, a parachute, a larger fuel tank, an ice-protection kit. The company holding it may sell the kit and the paperwork to owners of the listed models; the modification then becomes part of that aircraft's record. The FAA's list says what was approved and for which models, not how many aircraft carry it.
Source: FAA supplemental type certificates (Dynamic Regulatory System). Register counts from the FAA register of October 7, 2026.