SA51SW
Increase in gross weight to 22,500 pounds takeoff and 20,500 landing. Held by Signature Flight Support Corporation, which holds 335 approved modifications in all. Last revised August 31, 2000. System: other and general.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Lockheed Martin Aeronautics Company
- Models
- 18
- Type certificate
- A-723
- On this site
- Lockheed 18 13 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.