SA09366AC-D
Installation of S-TEC system 20/30 single and two axcis automatic flight guidance systems, Model ST-818-20/30. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised May 22, 1998. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Alexandria Aircraft LLC; Alexandria Aircraft LLC; Alexandria Aircraft LLC
- Models
- 17-30A, 17-31A, 17-31ATC
- Type certificates
- A18CE, A18CE, A18CE
- On this site
- Bellanca 17 Viking 628 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 20, 2026.