SA285SO
Installation of Lycoming IO-540- A1A5 powerplants and Hartzell HCA3XK-2B/7636D propellers. Held by Riley Aircraft CORP, which holds 31 approved modifications in all. Last revised November 29, 1984. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- The Cessna Aircraft Company; The Cessna Aircraft Company
- Models
- 320-1, 320
- Type certificates
- 3A25, 3A25
- On this site
- Cessna 320 137 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 21, 2026.