The U.S. aircraft register, updated daily
Approved modifications · supplemental type certificate · current · issued

SP9WE

Installation of Serv-Aero SA-10-P-18Q blades. Held by Serv-Aero Engr INC, which holds 3 approved modifications in all. Last revised November 26, 1980. System: propeller.

What it applies to

Kind of product
Propeller
Design holder
Hamilton Standard Division
Models
23E
Type certificate
P-603
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.