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

SR00450AT

Installation of a seat pan inspection panel. Held by Thoroughbred Aviation Maintenance INC, which holds 8 approved modifications in all. Last revised February 25, 2022. System: cabin, seats and restraints.

What it applies to

Kind of product
Aircraft
Design holder
MD Helicopter Inc.; MD Helicopter Inc.; MD Helicopter Inc.
Models
500N, 600N, 369 Series
Type certificates
H3WE, H3WE, H3WE
On this site
Md Helicopters Inc 500 15 registered
Md Helicopters Inc 600 11 registered
Md Helicopters Llc 369 34 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.