SA622CH
Replace two Pratt & Whitney model PT6A-112 engines with two Pratt & Whitney model PT6A-135/135A engines and Hartzell model HC-B3TN-3(C, K)/ T10178(B, K)-8R propellers. Held by Duncan Aviation, which holds 51 approved modifications in all. Last revised February 12, 1997. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- The Cessna Aircraft Company
- Models
- 425
- Type certificate
- A7CE
- On this site
- Cessna 425 Conquest I 161 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.