SA00888SE
Option 1: Install Walter M601-E11S engine and a Hartzell HC-B3TW-3/T10282N+4 propeller or a Walter M601-E11 engine and an Avia V508-E-AG 106/A propeller per the Master Drawing List and Installation Instructions given in Approved Model List SA00888SE. (Note: Prior to July 17, 2002, the model M601-E11S engine was designated as the model M601-E11 engine). Option 2: Install a Walter M601-D11 engine and Avia V508-E-AG 106/A propeller per Cascade Flying Service Master Drawing List CFS-MDL-0001 Rev G, dated June 15, 2004, and Cascade Flying Service Document CFS-IM-107, Rev A, dated July 29, 2003, “Installation Instructions for Walter Turbine Installation on Air Tractor 300 & 400 Series Ag Aircraft,” or later FAA-approved revisions to these documents. NOTE: The Air Tractor model AT-400, AT-402B, AT-502, AT-502B, and AT-503A airplanes are not eligible for modification under option 2. Held by Cascade Flying Service LLC, which holds 7 approved modifications in all. Last revised March 3, 2021. System: propeller.
What it applies to
- Kind of product
- Aircraft
- Design holder
- Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.; Air Tractor Inc.
- Models
- AT-401, AT-401A, AT-401B, AT-402, AT-402A, AT-402B, AT-502, AT-502B, AT-503A, AT-300, AT-301, AT-302, AT-400, AT-400A
- Type certificates
- A17SW, A17SW, A17SW, A17SW, A17SW, A17SW, A17SW, A17SW, A17SW, A9SW, A9SW, A9SW, A9SW, A9SW
- On this site
- Air Tractor Inc AT-301 83 registered
Air Tractor Inc AT-400 49 registered
Air Tractor Inc AT-401 68 registered
Air Tractor Inc AT-402 160 registered
Air Tractor Inc AT-502 501 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 22, 2026.