SA1464NM
Installation of Hartzell HC-B3TN-5NL/LT propellers on TPE331-5-252K engines (installed per STC SA1024SO) and AiResearch TPE331-5-251K and TPE331-5-254K engines. Held by Aero Air, LLC, which holds 12 approved modifications in all. Last revised January 14, 2004. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Twin Commander Aircraft Corporation; Twin Commander Aircraft Corporation; Twin Commander Aircraft Corporation; Twin Commander Aircraft Corporation
- Models
- 690C, 690A, 690, 690B
- Type certificates
- 2A4, 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 12, 2026.