SA09120AC-D
Installation of S-TEC System 55/55X Two Axis automatic flight guidance system, Model ST-603. Held by S-Tec Corporation, which holds 1,083 approved modifications in all. Last revised August 3, 2021. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.; Textron Aviation Inc.
- Models
- 337, 337A, 337B, 337C, 337D, 337E, 337F, 337G, 337H, M337B, P337H, T337B, T337C, T337D, T337E, T337F, T337G, T337H, T337H-SP
- Type certificates
- A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE, A6CE
- On this site
- Cessna M337 34 registered
Cessna P337 33 registered
Cessna T337 193 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 5, 2026.