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

ST09510SC

Installation of an AlliedSignal RDR-4B weather radar/predictive windshear system. Held by Department of Justice, which holds 2 approved modifications in all. Last revised November 1, 2001. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
McDonnell Douglas Corporation
Models
DC-9-15
Type certificate
A6WE
On this site
Douglas DC-9 7 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 19, 2026.