SA1184NW
Installation of Hartzell HC-B3TN-5/T10178E-13Q propellers on AiResearch Model TPE-331-43 series engines. Held by Pacific Propeller International LLC, which holds 27 approved modifications in all. Last revised June 30, 2005. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Twin Commander Aircraft Corporation; Twin Commander Aircraft Corporation; Twin Commander Aircraft Corporation
- Models
- 680-V, 680-W, 681
- Type certificates
- 2A4, 2A4, 2A4
- 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.