SA09232AC-D
Installation of S-TEC System 20/30 single and two axis automatic flight guidance systems, Model ST-687-20/30. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised May 30, 1997. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company
- Models
- 210G, 210H, 210J, T210G, T210H, T210J
- Type certificates
- 3A21, 3A21, 3A21, 3A21, 3A21, 3A21
- On this site
- Cessna 210 Centurion 1,528 registered
Cessna T210 Turbo Centurion 1,283 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.