SA7786SW-D
Installation of S-TEC System 40/50 single and two axis atutomatic flight guidance systems, model ST-399-40/50. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised January 28, 1991. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company
- Models
- R172H (USAF T-41D), R172E Series, R172G Series, R172F (USAF T-41D)
- Type certificates
- 3A17, 3A17, 3A17, 3A17
- On this site
- Cessna R172 Hawk XP 758 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.