SA4-31
Wright R1820-52 engines and Hamilton Standard 33D50/6511-9 propellers. Held by Mercer D W. Last revised January 1, 1960. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Douglas Aircraft Co. Inc.
- Models
- DC-2 (Army C-32)
- Type certificate
- ATC 540
- 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 7, 2026.