SA293NW
Installation of Franklin 6A-350-C1 or 6A-350-C2 engines, Hartzell HC-C2YF-1BF/F8459A -4 to -8, HC-C2YF-1BF/F8459A-4Q to -8Q, or McCauley 2A31C21/84S-4 to -8 propellers in accordance with Seaplane Flying, Inc. Assembly and Installation Instructions SF 20690, SF20821, or SF 20820, on Cessna Models 170A, 170B, 172, 172A, 172B through P, 175, 175A, 175B and 175C as defined in AML. 2.) Installation of Franklin 6A-350-C1R engines, Hartzell HC-C2YF-1BF/F8459A-4 to -8, HC-C2YF-1BF/F8459-4Q to -8, McCauley 2A31C21/84S-4 to -8 or 2A34C201/90DA-10 to -14 propellers in accordance with Seaplane Flying Inc. Assembly and Installation Instructions SF 20690 on Cessna Models 170A, 170B (Serial Numbers 20267 to 26504) as defined in AML. Held by Franklin Aircraft Engines INC., which holds 18 approved modifications in all. Last revised April 21, 2011. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company; Cessna Aircraft Company
- Models
- 172, 172A, 172B, 172C, 172D, 172E, 172F (USAF T-41A), 172G, 172H (USAF T-41A), 172I, 172K, 172L, 172M, 172N, 172P, 175, 175A, 175B, 175C, 170A, 170B
- Type certificates
- 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A12, 3A17, 3A17, 3A17, 3A17, A-799, A-799
- On this site
- Cessna 170 2,084 registered
Cessna 172 Skyhawk 20,669 registered
Cessna 175 Skylark 927 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.