SA491SW
Installation of Mitchell Automatic pilot AK135. Held by Mitchell Industries INC, which holds 37 approved modifications in all. Last revised January 20, 1966. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Cessna Aircraft Company
- Models
- 337
- Type certificate
- A6CE
- On this site
- Cessna 337 Skymaster 370 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.