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

ST233CH

Limit maximum payload capacity to7500 lbs. maximum. Held by Basler Flight Service INC, which holds 5 approved modifications in all. Last revised July 27, 1994. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
McDonnell Douglas Corporation; McDonnell Douglas Corporation; McDonnell Douglas Corporation
Models
Super DC-3, R4D-8, R4D-8Z
Type certificates
6A2, 6A2, 6A2
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.