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

SA100NW

Installation of cargo door, a 6 "G" barrier bulkhead, and a class "E" cargo compartment. Held by Rosembalm Aviation. Last revised April 24, 1975. System: airframe structure.

What it applies to

Kind of product
Aircraft
Design holder
The Boeing Company
Models
DC-6B
Type certificate
6A4
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.