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

SA2-993

Installation of P&W R-985 Fuel Injection Engines, as modified by STC SE1-391. Held by Staggerwing Museum Foundation INC., which holds 123 approved modifications in all. Last revised October 6, 2006. System: engine.

What it applies to

Kind of product
Aircraft
Design holder
Hawker Beechcraft Corporation; Hawker Beechcraft Corporation
Models
E18S, E18S-9700
Type certificates
A-765, A-765
On this site
Beechcraft E18 58 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 7, 2026.