SA4-171
Approval to use 1,350 hp for takeoff with Wright R1820-56A, -66 and -72A engines and 1,300 hp, with Wright R-1820-56 and -72 engines with Hamilton Standard33D50/6511-12 and -12S propellers. Held by Garside'S Aircraft & Engine Parts & Svc INC, which holds 32 approved modifications in all. Last revised February 1, 1984. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Lockheed Aircraft Corporation
- Models
- Lockheed 18
- Type certificate
- A-723
- 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 8, 2026.