SE04117CH
Conversion of Continental Motors engine models TSIO-520-C, -G, -H, -M & -R to the naturally aspirated IO-520-A, -F, -J & -L. Held by Western Skyways. Last revised September 30, 2016. System: engine.
What it applies to
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 22, 2026.