SA5355SW-D
Installation of S-TEC System 40/50 single and two axis automatic flight guidance systems, Model ST-252-40/50. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised November 29, 1984. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Piper Aircraft Inc.; Piper Aircraft Inc.
- Models
- PA-23-250, PA-E23-250
- Type certificates
- 1A10, 1A10
- On this site
- Piper PA-23 Apache and Aztec 1,316 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.