SP09397SC
Installation of a propeller blade seal. Held by Schweis Robert W, which holds 8 approved modifications in all. Last revised November 18, 1997. System: propeller.
What it applies to
- Kind of product
- Propeller
- Design holder
- Hamilton Standard Division
- Models
- 12D
- Type certificate
- P-257
- 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.