SA4172WE
Installation of Hamilton Standard 3D40-209 hub with 6101A-18 propeller blades. Held by Mid Cal Dusters. Last revised March 18, 1999. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Air Tractor Inc.
- Models
- AT-301
- Type certificate
- A9SW
- On this site
- Air Tractor Inc AT-301 84 registered
- 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 20, 2026.