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

SA1635SO

Installation of replacement fuel cell assemblies. (SEE LIMITATIONS). Held by Ffc Manufacturing, which holds 86 approved modifications in all. Last revised March 10, 1995. System: other and general.

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
A185F, 185E, 185D, 185C, 185B, 185, 185A
Type certificates
3A24, 3A24, 3A24, 3A24, 3A24, 3A24, 3A24
On this site
Cessna 185 Skywagon 227 registered
Cessna A185 Skywagon 1,372 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.