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

SA117NW

Installation of Allison 250-B17 or 250-B17B engines and related changes. Held by Alaskan Turbine S.T.O.L. Aircraft. Last revised November 8, 2000. System: engine.

What it applies to

Kind of product
Aircraft
Design holder
The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company; The Cessna Aircraft Company
Models
401A, 402, 402A, 414, 401B, 401, 402B
Type certificates
A7CE, A7CE, A7CE, A7CE, A7CE, A7CE, A7CE
On this site
Cessna 401 51 registered
Cessna 402 174 registered
Cessna 414 Chancellor 605 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.