SA360EA
Installation of Franklin Engine Co Inc Model 6A-335-B engine with McCauley 2A31C21/84S-8 propeller and new engine mount and associated components. Held by Franklin Engine CO INC, which holds 7 approved modifications in all. Last revised June 19, 1970. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company
- Models
- 170B, 172, 172A
- Type certificates
- A-799, 3A12, 3A12
- On this site
- Cessna 170 2,085 registered
Cessna 172 Skyhawk 20,676 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.